Add a function for getting language config by injection layer

Sourcehut has outages occasionally that cause the CI and from-source
builds to fail. It also doesn't setup redirects when a user renames
themselves, so if a user that publishes a tree-sitter grammar we use
changes their sourcehut name then it breaks the build and any prior
builds using that grammar.

For now let's remove them from the default build. It's a bandaid over
a larger reliability and trust problem with the grammar repositories
but it should fix the build for now.

.cargo/config.toml

@@ -0,0 +1,3 @@
+[alias]
+xtask = "run --package xtask --"
+integration-test = "test --features integration --profile integration --workspace --test integration"

.envrc

@@ -1,2 +1,7 @@
 watch_file shell.nix
-use flake
+watch_file flake.lock
+watch_file rust-toolchain.toml
+
+# try to use flakes, if it fails use normal nix (ie. shell.nix)
+use flake || use nix
+eval "$shellHook"

.gitattributes

@@ -0,0 +1,11 @@
+# Auto detect text files and perform normalization
+*          text=auto
+
+*.rs       text diff=rust
+*.toml     text diff=toml
+
+*.scm      text diff=scheme
+*.md       text diff=markdown
+
+book/theme/highlight.js linguist-vendored
+Cargo.lock text

.github/FUNDING.yml

@@ -0,0 +1 @@
+open_collective: helix-editor

.github/ISSUE_TEMPLATE/blank_issue.md

@@ -0,0 +1,4 @@
+---
+name: Blank Issue
+about: Create a blank issue.
+---

.github/ISSUE_TEMPLATE/bug_report.yaml

@@ -0,0 +1,78 @@
+name: Bug Report
+description: Create a report to help us improve
+labels: C-bug
+body:
+  - type: markdown
+    attributes:
+      value: Thank you for filing a bug report! 🐛
+  - type: textarea
+    id: problem
+    attributes:
+      label: Summary
+      description: >
+        Please provide a short summary of the bug, along with any information
+        you feel relevant to replicate the bug.
+    validations:
+      required: true
+  - type: textarea
+    id: reproduction-steps
+    attributes:
+      label: Reproduction Steps
+      value: |
+        <!-- Ideally provide a key sequence and/or asciinema.org recording. --> 
+
+        I tried this:
+
+        1. `hx`
+
+        I expected this to happen:
+
+        Instead, this happened:
+  - type: textarea
+    id: helix-log
+    attributes:
+      label: Helix log
+      description: See `hx -h` for log file path. If you can reproduce the issue run `RUST_BACKTRACE=1 hx -vv` to generate a more detailed log file.
+      value: |
+        <details><summary>~/.cache/helix/helix.log</summary>
+
+        ```
+        please provide a copy of `~/.cache/helix/helix.log` here if possible, you may need to redact some of the lines
+        ```
+
+        </details>
+  - type: input
+    id: platform
+    attributes:
+      label: Platform
+      placeholder: Linux / macOS / Windows
+    validations:
+      required: true
+  - type: input
+    id: terminal-emulator
+    attributes:
+      label: Terminal Emulator
+      placeholder: wezterm 20220101-133340-7edc5b5a
+    validations:
+      required: true
+  - type: input
+    id: installation-method
+    attributes:
+      label: Installation Method
+      description: >
+        How you installed Helix - from a package manager like Homebrew or the
+        AUR, built from source, downloaded a binary from the releases page, etc.
+      placeholder: "source / brew / nixpkgs / flake / releases page"
+    validations:
+      required: true
+  - type: input
+    id: helix-version
+    attributes:
+      label: Helix Version
+      description: >
+        Helix version (`hx -V` if using a release, `git describe` if building
+        from master).
+        **Make sure that you are using the [latest helix release](https://github.com/helix-editor/helix/releases) or a newer master build**
+      placeholder: "helix 22.12 (5eaa6d97)"
+    validations:
+      required: true

.github/ISSUE_TEMPLATE/enhancement.md

@@ -0,0 +1,13 @@
+---
+name: Enhancement
+about: Suggest an improvement
+title: ''
+labels: C-enhancement
+assignees: ''
+---
+
+<!--
+Your enhancement may already be reported!
+Please search on the issue tracker before creating a new issue.
+If this is an idea for a feature, please open an "Idea" Discussion instead.
+-->

.github/dependabot.yml

@@ -0,0 +1,14 @@
+# Please see the documentation for all configuration options:
+# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: "cargo"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"

.github/workflows/build.yml

@@ -1,134 +1,118 @@
 name: Build
 on:
+  pull_request:
   push:
     branches:
       - master
-  pull_request:
-    branches:
-      - master
+  merge_group:
+  schedule:
+    - cron: '00 01 * * *'
 
 jobs:
   check:
-    name: Check
+    name: Check (msrv)
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
-        uses: actions/checkout@v2
-        with:
-          submodules: true
-
+        uses: actions/checkout@v4
       - name: Install stable toolchain
-        uses: actions-rs/toolchain@v1
+        uses: helix-editor/rust-toolchain@v1
         with:
           profile: minimal
-          toolchain: stable
           override: true
 
-      - name: Cache cargo registry
-        uses: actions/cache@v1
+      - uses: Swatinem/rust-cache@v2
         with:
-          path: ~/.cargo/registry
-          key: ${{ runner.os }}-v1-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
-
-      - name: Cache cargo index
-        uses: actions/cache@v1
-        with:
-          path: ~/.cargo/git
-          key: ${{ runner.os }}-v1-cargo-index-${{ hashFiles('**/Cargo.lock') }}
-
-      - name: Cache cargo target dir
-        uses: actions/cache@v1
-        with:
-          path: target
-          key: ${{ runner.os }}-v1-cargo-build-target-${{ hashFiles('**/Cargo.lock') }}
+          shared-key: "build"
 
       - name: Run cargo check
-        uses: actions-rs/cargo@v1
-        with:
-          command: check
+        run: cargo check
 
   test:
     name: Test Suite
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    env:
+      RUST_BACKTRACE: 1
+      HELIX_LOG_LEVEL: info
     steps:
       - name: Checkout sources
-        uses: actions/checkout@v2
-        with:
-          submodules: true
+        uses: actions/checkout@v4
 
       - name: Install stable toolchain
-        uses: actions-rs/toolchain@v1
-        with:
-          profile: minimal
-          toolchain: stable
-          override: true
+        uses: dtolnay/rust-toolchain@1.70
 
-      - name: Cache cargo registry
-        uses: actions/cache@v1
+      - uses: Swatinem/rust-cache@v2
         with:
-          path: ~/.cargo/registry
-          key: ${{ runner.os }}-v1-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
+          shared-key: "build"
 
-      - name: Cache cargo index
-        uses: actions/cache@v1
+      - name: Cache test tree-sitter grammar
+        uses: actions/cache@v3
         with:
-          path: ~/.cargo/git
-          key: ${{ runner.os }}-v1-cargo-index-${{ hashFiles('**/Cargo.lock') }}
-
-      - name: Cache cargo target dir
-        uses: actions/cache@v1
-        with:
-          path: target
-          key: ${{ runner.os }}-v1-cargo-build-target-${{ hashFiles('**/Cargo.lock') }}
+          path: runtime/grammars
+          key: ${{ runner.os }}-stable-v${{ env.CACHE_VERSION }}-tree-sitter-grammars-${{ hashFiles('languages.toml') }}
+          restore-keys: ${{ runner.os }}-stable-v${{ env.CACHE_VERSION }}-tree-sitter-grammars-
 
       - name: Run cargo test
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
+        run: cargo test --workspace
+
+      - name: Run cargo integration-test
+        run: cargo integration-test
+
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
 
   lints:
     name: Lints
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
-        uses: actions/checkout@v2
-        with:
-          submodules: true
+        uses: actions/checkout@v4
 
       - name: Install stable toolchain
-        uses: actions-rs/toolchain@v1
+        uses: dtolnay/rust-toolchain@1.70
         with:
-          profile: minimal
-          toolchain: stable
-          override: true
           components: rustfmt, clippy
 
-      - name: Cache cargo registry
-        uses: actions/cache@v1
+      - uses: Swatinem/rust-cache@v2
         with:
-          path: ~/.cargo/registry
-          key: ${{ runner.os }}-v1-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
-
-      - name: Cache cargo index
-        uses: actions/cache@v1
-        with:
-          path: ~/.cargo/git
-          key: ${{ runner.os }}-v1-cargo-index-${{ hashFiles('**/Cargo.lock') }}
-
-      - name: Cache cargo target dir
-        uses: actions/cache@v1
-        with:
-          path: target
-          key: ${{ runner.os }}-v1-cargo-build-target-${{ hashFiles('**/Cargo.lock') }}
+          shared-key: "build"
 
       - name: Run cargo fmt
-        uses: actions-rs/cargo@v1
-        with:
-          command: fmt
-          args: --all -- --check
+        run: cargo fmt --all --check
 
       - name: Run cargo clippy
-        uses: actions-rs/cargo@v1
+        run: cargo clippy --workspace --all-targets -- -D warnings
+
+      - name: Run cargo doc
+        run: cargo doc --no-deps --workspace --document-private-items
+        env:
+          RUSTDOCFLAGS: -D warnings
+
+  docs:
+    name: Docs
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v4
+
+      - name: Install stable toolchain
+        uses: dtolnay/rust-toolchain@1.70
+
+      - uses: Swatinem/rust-cache@v2
         with:
-          command: clippy
-          args: -- -D warnings
+          shared-key: "build"
+
+      - name: Validate queries
+        run: cargo xtask query-check
+
+      - name: Generate docs
+        run: cargo xtask docgen
+
+      - name: Check uncommitted documentation changes
+        run: |
+          git diff
+          git diff-files --quiet \
+            || (echo "Run 'cargo xtask docgen', commit the changes and push again" \
+            && exit 1)
+

.github/workflows/cachix.yml

@@ -0,0 +1,26 @@
+# Publish the Nix flake outputs to Cachix
+name: Cachix
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  publish:
+    name: Publish Flake
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout sources
+      uses: actions/checkout@v4
+
+    - name: Install nix
+      uses: cachix/install-nix-action@v24
+
+    - name: Authenticate with Cachix
+      uses: cachix/cachix-action@v13
+      with:
+        name: helix
+        authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+
+    - name: Build nix flake
+      run: nix build -L

.github/workflows/gh-pages.yml

@@ -0,0 +1,41 @@
+name: Github Pages
+
+on:
+  push:
+    branches:
+      - master
+    tags:
+      - '*'
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup mdBook
+        uses: peaceiris/actions-mdbook@v1
+        with:
+          mdbook-version: 'latest'
+          # mdbook-version: '0.4.8'
+
+      - run: mdbook build book
+      
+      - name: Set output directory
+        run: |
+          OUTDIR=$(basename ${{ github.ref }})
+          echo "OUTDIR=$OUTDIR" >> $GITHUB_ENV
+
+      - name: Deploy stable
+        uses: peaceiris/actions-gh-pages@v3
+        if: startswith(github.ref, 'refs/tags/')
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: ./book/book
+
+      - name: Deploy
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: ./book/book
+          destination_dir: ./${{ env.OUTDIR }}

.github/workflows/languages.toml

@@ -0,0 +1,26 @@
+# This languages.toml is used for testing in CI.
+
+[[language]]
+name = "rust"
+scope = "source.rust"
+injection-regex = "rust"
+file-types = ["rs"]
+comment-token = "//"
+roots = ["Cargo.toml", "Cargo.lock"]
+indent = { tab-width = 4, unit = "    " }
+
+[[grammar]]
+name = "rust"
+source = { git = "https://github.com/tree-sitter/tree-sitter-rust", rev = "0431a2c60828731f27491ee9fdefe25e250ce9c9" }
+
+[[language]]
+name = "nix"
+scope = "source.nix"
+injection-regex = "nix"
+file-types = ["nix"]
+shebangs = []
+roots = []
+comment-token = "#"
+
+# A grammar entry is not necessary for this language - it is only used for
+# testing TOML merging behavior.

.github/workflows/release.yml

@@ -1,42 +1,97 @@
 name: Release
 on:
-  # schedule:
-  # - cron: '0 0 * * *' # midnight UTC
-
   push:
     tags:
-    - 'v[0-9]+.[0-9]+.[0-9]+'
-    ## - release
+    - '[0-9]+.[0-9]+'
+    - '[0-9]+.[0-9]+.[0-9]+'
+    branches:
+    - 'patch/ci-release-*'
+  pull_request:
+    paths:
+    - '.github/workflows/release.yml'
+
+env:
+  # Preview mode: Publishes the build output as a CI artifact instead of creating
+  # a release, allowing for manual inspection of the output. This mode is
+  # activated if the CI run was triggered by events other than pushed tags, or
+  # if the repository is a fork.
+  preview: ${{ !startsWith(github.ref, 'refs/tags/') || github.repository != 'helix-editor/helix' }}
 
 jobs:
+  fetch-grammars:
+    name: Fetch Grammars
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v4
+
+      - name: Install stable toolchain
+        uses: dtolnay/rust-toolchain@stable
+
+      - uses: Swatinem/rust-cache@v2
+
+      - name: Fetch tree-sitter grammars
+        run: cargo run --package=helix-loader --bin=hx-loader
+
+      - name: Bundle grammars
+        run: tar cJf grammars.tar.xz -C runtime/grammars/sources .
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: grammars
+          path: grammars.tar.xz
+
   dist:
     name: Dist
+    needs: [fetch-grammars]
+    env:
+      # For some builds, we use cross to test on 32-bit and big-endian
+      # systems.
+      CARGO: cargo
+      # When CARGO is set to CROSS, this is set to `--target matrix.target`.
+      TARGET_FLAGS:
+      # When CARGO is set to CROSS, TARGET_DIR includes matrix.target.
+      TARGET_DIR: ./target
+      # Emit backtraces on panics.
+      RUST_BACKTRACE: 1
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false # don't fail other jobs if one fails
       matrix:
-        build: [x86_64-linux, aarch64-linux, x86_64-macos, x86_64-windows] #, x86_64-win-gnu, win32-msvc
+        build: [x86_64-linux, x86_64-macos, x86_64-windows] #, x86_64-win-gnu, win32-msvc
         include:
         - build: x86_64-linux
-          os: ubuntu-20.04
+          os: ubuntu-latest
           rust: stable
           target: x86_64-unknown-linux-gnu
           cross: false
         - build: aarch64-linux
-          os: ubuntu-20.04
+          os: ubuntu-latest
           rust: stable
           target: aarch64-unknown-linux-gnu
           cross: true
+        # - build: riscv64-linux
+        #   os: ubuntu-latest
+        #   rust: stable
+        #   target: riscv64gc-unknown-linux-gnu
+        #   cross: true
         - build: x86_64-macos
           os: macos-latest
           rust: stable
           target: x86_64-apple-darwin
           cross: false
         - build: x86_64-windows
-          os: windows-2019
+          os: windows-latest
           rust: stable
           target: x86_64-pc-windows-msvc
           cross: false
+        # 23.03: build issues
+        - build: aarch64-macos
+          os: macos-latest
+          rust: stable
+          target: aarch64-apple-darwin
+          cross: false
+          skip_tests: true  # x86_64 host can't run aarch64 code
         # - build: x86_64-win-gnu
         #   os: windows-2019
         #   rust: stable-x86_64-gnu
@@ -48,55 +103,124 @@ jobs:
 
     steps:
       - name: Checkout sources
-        uses: actions/checkout@v2
-        with:
-          submodules: true
+        uses: actions/checkout@v4
+
+      - name: Download grammars
+        uses: actions/download-artifact@v4
+
+      - name: Move grammars under runtime
+        if: "!startsWith(matrix.os, 'windows')"
+        run: |
+          mkdir -p runtime/grammars/sources
+          tar xJf grammars/grammars.tar.xz -C runtime/grammars/sources
+
+      # The rust-toolchain action ignores rust-toolchain.toml files.
+      # Removing this before building with cargo ensures that the rust-toolchain
+      # is considered the same between installation and usage.
+      - name: Remove the rust-toolchain.toml file
+        run: rm rust-toolchain.toml
 
       - name: Install ${{ matrix.rust }} toolchain
-        uses: actions-rs/toolchain@v1
+        uses: dtolnay/rust-toolchain@master
         with:
-          profile: minimal
           toolchain: ${{ matrix.rust }}
           target: ${{ matrix.target }}
-          override: true
+
+      # Install a pre-release version of Cross
+      # TODO: We need to pre-install Cross because we need cross-rs/cross#591 to
+      #       get a newer C++ compiler toolchain. Remove this step when Cross
+      #       0.3.0, which includes cross-rs/cross#591, is released.
+      - name: Install Cross
+        if: "matrix.cross"
+        run: |
+          cargo install cross --git https://github.com/cross-rs/cross.git --rev 47df5c76e7cba682823a0b6aa6d95c17b31ba63a
+          echo "CARGO=cross" >> $GITHUB_ENV
+        # echo "TARGET_FLAGS=--target ${{ matrix.target }}" >> $GITHUB_ENV
+        # echo "TARGET_DIR=./target/${{ matrix.target }}" >> $GITHUB_ENV
+
+      - name: Show command used for Cargo
+        run: |
+          echo "cargo command is: ${{ env.CARGO }}"
+          echo "target flag is: ${{ env.TARGET_FLAGS }}"
 
       - name: Run cargo test
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
-          args: --locked
+        if: "!matrix.skip_tests"
+        run: ${{ env.CARGO }} test --release --locked --target ${{ matrix.target }} --workspace
+
+      - name: Set profile.release.strip = true
+        shell: bash
+        run: |
+          cat >> .cargo/config.toml <<EOF
+          [profile.release]
+          strip = true
+          EOF
 
       - name: Build release binary
-        uses: actions-rs/cargo@v1
-        with:
-          use-cross: ${{ matrix.cross }}
-          command: build
-          args: --release --locked --target ${{ matrix.target }}
+        run: ${{ env.CARGO }} build --release --locked --target ${{ matrix.target }}
 
-      - name: Strip release binary (linux and macos)
-        if: matrix.build == 'x86_64-linux' || matrix.build == 'x86_64-macos'
-        run: strip "target/${{ matrix.target }}/release/hx"
-
-      - name: Strip release binary (arm)
-        if: matrix.build == 'aarch64-linux'
+      - name: Build AppImage
+        shell: bash
+        if: matrix.build == 'x86_64-linux'
         run: |
-          docker run --rm -v \
-            "$PWD/target:/target:Z" \
-            rustembedded/cross:${{ matrix.target }} \
-            aarch64-linux-gnu-strip \
-            /target/${{ matrix.target }}/release/hx
+          # Required as of 22.x https://github.com/AppImage/AppImageKit/wiki/FUSE
+          sudo add-apt-repository universe
+          sudo apt install libfuse2
+
+          mkdir dist
+
+          name=dev
+          if [[ $GITHUB_REF == refs/tags/* ]]; then
+            name=${GITHUB_REF:10}
+          fi
+
+          build="${{ matrix.build }}"
+
+          export VERSION="$name"
+          export ARCH=${build%-linux}
+          export APP=helix
+          export OUTPUT="helix-$VERSION-$ARCH.AppImage"
+          export UPDATE_INFORMATION="gh-releases-zsync|$GITHUB_REPOSITORY_OWNER|helix|latest|$APP-*-$ARCH.AppImage.zsync"
+
+          mkdir -p "$APP.AppDir"/usr/{bin,lib/helix}
+
+          cp "target/${{ matrix.target }}/release/hx" "$APP.AppDir/usr/bin/hx"
+          rm -rf runtime/grammars/sources
+          cp -r runtime "$APP.AppDir/usr/lib/helix/runtime"
+
+          cat << 'EOF' > "$APP.AppDir/AppRun"
+          #!/bin/sh
+
+          APPDIR="$(dirname "$(readlink -f "${0}")")"
+          HELIX_RUNTIME="$APPDIR/usr/lib/helix/runtime" exec "$APPDIR/usr/bin/hx" "$@"
+          EOF
+          chmod 755 "$APP.AppDir/AppRun"
+
+          curl -Lo linuxdeploy-x86_64.AppImage \
+              https://github.com/linuxdeploy/linuxdeploy/releases/download/continuous/linuxdeploy-x86_64.AppImage
+          chmod +x linuxdeploy-x86_64.AppImage
+
+          ./linuxdeploy-x86_64.AppImage \
+              --appdir "$APP.AppDir" -d contrib/Helix.desktop \
+              -i contrib/helix.png --output appimage
+
+          mv "$APP-$VERSION-$ARCH.AppImage" \
+              "$APP-$VERSION-$ARCH.AppImage.zsync" dist
 
       - name: Build archive
         shell: bash
         run: |
-          mkdir dist
+          mkdir -p dist
           if [ "${{ matrix.os }}" = "windows-2019" ]; then
             cp "target/${{ matrix.target }}/release/hx.exe" "dist/"
           else
             cp "target/${{ matrix.target }}/release/hx" "dist/"
           fi
+          if [ -d runtime/grammars/sources ]; then
+            rm -rf runtime/grammars/sources
+          fi
+          cp -r runtime dist
 
-      - uses: actions/upload-artifact@v1
+      - uses: actions/upload-artifact@v4
         with:
           name: bins-${{ matrix.build }}
           path: dist
@@ -107,33 +231,22 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
-        uses: actions/checkout@v2
-        with:
-          submodules: false
+        uses: actions/checkout@v4
 
-      - uses: actions/download-artifact@v2
-        # with:
-        #   path: dist
-      # - run: ls -al ./dist
-      - run: ls -al bins-*
-
-      - name: Calculate tag name
-        run: |
-          name=dev
-          if [[ $GITHUB_REF == refs/tags/v* ]]; then
-            name=${GITHUB_REF:10}
-          fi
-          echo ::set-output name=val::$name
-          echo TAG=$name >> $GITHUB_ENV
-        id: tagname
+      - uses: actions/download-artifact@v4
 
       - name: Build archive
         shell: bash
         run: |
           set -ex
 
-          rm -rf tmp
-          mkdir tmp
+          source="$(pwd)"
+          mkdir -p runtime/grammars/sources
+          tar xJf grammars/grammars.tar.xz -C runtime/grammars/sources
+          rm -rf grammars
+
+          cd "$(mktemp -d)"
+          mv $source/bins-* .
           mkdir dist
 
           for dir in bins-* ; do
@@ -141,25 +254,42 @@ jobs:
               if [[ $platform =~ "windows" ]]; then
                   exe=".exe"
               fi
-              pkgname=helix-$TAG-$platform
-              mkdir tmp/$pkgname
-              cp LICENSE README.md tmp/$pkgname
-              cp -r runtime tmp/$pkgname/
-              mv bins-$platform/hx$exe tmp/$pkgname
-              chmod +x tmp/$pkgname/hx$exe
+              pkgname=helix-$GITHUB_REF_NAME-$platform
+              mkdir -p $pkgname
+              cp $source/LICENSE $source/README.md $pkgname
+              mkdir $pkgname/contrib
+              cp -r $source/contrib/completion $pkgname/contrib
+              mv bins-$platform/runtime $pkgname/
+              mv bins-$platform/hx$exe $pkgname
+              chmod +x $pkgname/hx$exe
+
+              if [[ "$platform" = "x86_64-linux" ]]; then
+                  mv bins-$platform/helix-*.AppImage* dist/
+              fi
 
               if [ "$exe" = "" ]; then
-                  tar cJf dist/$pkgname.tar.xz -C tmp $pkgname
+                  tar cJf dist/$pkgname.tar.xz $pkgname
               else
-                  (cd tmp && 7z a -r ../dist/$pkgname.zip $pkgname)
+                  7z a -r dist/$pkgname.zip $pkgname
               fi
           done
 
+          tar cJf dist/helix-$GITHUB_REF_NAME-source.tar.xz -C $source .
+          mv dist $source/
+
       - name: Upload binaries to release
         uses: svenstaro/upload-release-action@v2
+        if: env.preview == 'false'
         with:
           repo_token: ${{ secrets.GITHUB_TOKEN }}
           file: dist/*
           file_glob: true
-          tag: ${{ steps.tagname.outputs.val }}
+          tag: ${{ github.ref_name }}
           overwrite: true
+      
+      - name: Upload binaries as artifact
+        uses: actions/upload-artifact@v4
+        if: env.preview == 'true'
+        with:
+          name: release
+          path: dist/*

.gitignore

@@ -1,4 +1,5 @@
 target
 .direnv
 helix-term/rustfmt.toml
-helix-syntax/languages/
+result
+runtime/grammars

.gitmodules

@@ -1,84 +0,0 @@
-[submodule "helix-syntax/languages/tree-sitter-cpp"]
-	path = helix-syntax/languages/tree-sitter-cpp
-	url = https://github.com/tree-sitter/tree-sitter-cpp
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-javascript"]
-	path = helix-syntax/languages/tree-sitter-javascript
-	url = https://github.com/tree-sitter/tree-sitter-javascript
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-julia"]
-	path = helix-syntax/languages/tree-sitter-julia
-	url = https://github.com/tree-sitter/tree-sitter-julia
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-python"]
-	path = helix-syntax/languages/tree-sitter-python
-	url = https://github.com/tree-sitter/tree-sitter-python
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-typescript"]
-	path = helix-syntax/languages/tree-sitter-typescript
-	url = https://github.com/tree-sitter/tree-sitter-typescript
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-agda"]
-	path = helix-syntax/languages/tree-sitter-agda
-	url = https://github.com/tree-sitter/tree-sitter-agda
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-go"]
-	path = helix-syntax/languages/tree-sitter-go
-	url = https://github.com/tree-sitter/tree-sitter-go
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-ruby"]
-	path = helix-syntax/languages/tree-sitter-ruby
-	url = https://github.com/tree-sitter/tree-sitter-ruby
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-java"]
-	path = helix-syntax/languages/tree-sitter-java
-	url = https://github.com/tree-sitter/tree-sitter-java
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-php"]
-	path = helix-syntax/languages/tree-sitter-php
-	url = https://github.com/tree-sitter/tree-sitter-php
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-html"]
-	path = helix-syntax/languages/tree-sitter-html
-	url = https://github.com/tree-sitter/tree-sitter-html
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-scala"]
-	path = helix-syntax/languages/tree-sitter-scala
-	url = https://github.com/tree-sitter/tree-sitter-scala
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-bash"]
-	path = helix-syntax/languages/tree-sitter-bash
-	url = https://github.com/tree-sitter/tree-sitter-bash
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-rust"]
-	path = helix-syntax/languages/tree-sitter-rust
-	url = https://github.com/tree-sitter/tree-sitter-rust
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-json"]
-	path = helix-syntax/languages/tree-sitter-json
-	url = https://github.com/tree-sitter/tree-sitter-json
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-css"]
-	path = helix-syntax/languages/tree-sitter-css
-	url = https://github.com/tree-sitter/tree-sitter-css
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-c-sharp"]
-	path = helix-syntax/languages/tree-sitter-c-sharp
-	url = https://github.com/tree-sitter/tree-sitter-c-sharp
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-c"]
-	path = helix-syntax/languages/tree-sitter-c
-	url = https://github.com/tree-sitter/tree-sitter-c
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-haskell"]
-	path = helix-syntax/languages/tree-sitter-haskell
-	url = https://github.com/tree-sitter/tree-sitter-haskell
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-swift"]
-	path = helix-syntax/languages/tree-sitter-swift
-	url = https://github.com/tree-sitter/tree-sitter-swift
-	shallow = true
-[submodule "helix-syntax/languages/tree-sitter-toml"]
-	path = helix-syntax/languages/tree-sitter-toml
-	url = https://github.com/ikatyang/tree-sitter-toml
-	shallow = true

.ignore

@@ -0,0 +1,2 @@
+# Things that we don't want ripgrep to search that we do want in git
+# https://github.com/BurntSushi/ripgrep/blob/master/GUIDE.md#automatic-filtering

Cargo.toml

@@ -1,16 +1,50 @@
 [workspace]
+resolver = "2"
 members = [
   "helix-core",
   "helix-view",
   "helix-term",
   "helix-tui",
-  "helix-syntax",
   "helix-lsp",
+  "helix-event",
+  "helix-dap",
+  "helix-loader",
+  "helix-vcs",
+  "helix-parsec",
+  "xtask",
 ]
 
-# Build helix-syntax in release mode to make the code path faster in development.
-# [profile.dev.package."helix-syntax"]
-# opt-level = 3
+default-members = [
+  "helix-term"
+]
 
-[profile.dev]
-split-debuginfo = "unpacked"
+[profile.release]
+lto = "thin"
+# debug = true
+
+[profile.opt]
+inherits = "release"
+lto = "fat"
+codegen-units = 1
+# strip = "debuginfo" # TODO: or strip = true
+opt-level = 3
+
+[profile.integration]
+inherits = "test"
+package.helix-core.opt-level = 2
+package.helix-tui.opt-level = 2
+package.helix-term.opt-level = 2
+
+[workspace.dependencies]
+tree-sitter = { version = "0.20", git = "https://github.com/tree-sitter/tree-sitter", rev = "ab09ae20d640711174b8da8a654f6b3dec93da1a" }
+nucleo = "0.2.0"
+
+[workspace.package]
+version = "23.10.0"
+edition = "2021"
+authors = ["Blaž Hrastnik <blaz@mxxn.io>"]
+categories = ["editor"]
+repository = "https://github.com/helix-editor/helix"
+homepage = "https://helix-editor.com"
+license = "MPL-2.0"
+rust-version = "1.70"

README.md

@@ -1,16 +1,34 @@
-# Helix
+<div align="center">
 
+<h1>
+<picture>
+  <source media="(prefers-color-scheme: dark)" srcset="logo_dark.svg">
+  <source media="(prefers-color-scheme: light)" srcset="logo_light.svg">
+  <img alt="Helix" height="128" src="logo_light.svg">
+</picture>
+</h1>
 
-[![Build status](https://github.com/helix-editor/helix/workflows/ci/badge.svg)](https://github.com/helix-editor/helix/actions)
+[![Build status](https://github.com/helix-editor/helix/actions/workflows/build.yml/badge.svg)](https://github.com/helix-editor/helix/actions)
+[![GitHub Release](https://img.shields.io/github/v/release/helix-editor/helix)](https://github.com/helix-editor/helix/releases/latest)
+[![Documentation](https://shields.io/badge/-documentation-452859)](https://docs.helix-editor.com/)
+[![GitHub contributors](https://img.shields.io/github/contributors/helix-editor/helix)](https://github.com/helix-editor/helix/graphs/contributors)
+[![Matrix Space](https://img.shields.io/matrix/helix-community:matrix.org)](https://matrix.to/#/#helix-community:matrix.org)
+
+</div>
 
 ![Screenshot](./screenshot.png)
 
-A kakoune / neovim inspired editor, written in Rust.
+A [Kakoune](https://github.com/mawww/kakoune) / [Neovim](https://github.com/neovim/neovim) inspired editor, written in Rust.
 
-The editing model is very heavily based on kakoune; during development I found
-myself agreeing with most of kakoune's design decisions.
+The editing model is very heavily based on Kakoune; during development I found
+myself agreeing with most of Kakoune's design decisions.
 
-For more information, see the [website](https://helix-editor.com).
+For more information, see the [website](https://helix-editor.com) or
+[documentation](https://docs.helix-editor.com/).
+
+All shortcuts/keymaps can be found [in the documentation on the website](https://docs.helix-editor.com/keymap.html).
+
+[Troubleshooting](https://github.com/helix-editor/helix/wiki/Troubleshooting)
 
 # Features
 
@@ -20,43 +38,27 @@ For more information, see the [website](https://helix-editor.com).
 - Smart, incremental syntax highlighting and code editing via tree-sitter
 
 It's a terminal-based editor first, but I'd like to explore a custom renderer
-(similar to emacs) in wgpu or skulpin.
+(similar to Emacs) in wgpu or skulpin.
+
+Note: Only certain languages have indentation definitions at the moment. Check
+`runtime/queries/<lang>/` for `indents.scm`.
 
 # Installation
 
-Note: Only the Rust syntax has indentation definitions at the moment.
+[Installation documentation](https://docs.helix-editor.com/install.html).
 
-We provide packaging for various distributions, but here's a quick method to
-build from source.
-
-```
-git clone --recurse-submodules --shallow-submodules -j8 https://github.com/helix-editor/helix
-cd helix
-cargo install --path helix-term
-```
-
-This will install the `hx` binary to `$HOME/.cargo/bin`.
-
-Now copy the `runtime/` directory somewhere. Helix will by default look for the
-runtime inside the same folder as the executable, but that can be overriden via
-the `HELIX_RUNTIME` environment variable.
+[![Packaging status](https://repology.org/badge/vertical-allrepos/helix.svg)](https://repology.org/project/helix/versions)
 
 # Contributing
 
-Contributors are very welcome! **No contribution is too small and all contributions are valued.**
-
-Some suggestions to get started:
-
-- You can look at the [good first issue](https://github.com/helix-editor/helix/labels/good%20first%20issue) label on the issue tracker.
-- Help with packaging on various distributions needed!
-- If your preferred language is missing, integrating a tree-sitter grammar for
-    it and defining syntax highlight queries for it is straight forward and
-    doesn't require much knowledge of the internals.
-
-We provide an [architecture.md](./docs/architecture.md) that should give you
-a good overview of the internals.
+Contributing guidelines can be found [here](./docs/CONTRIBUTING.md).
 
 # Getting help
 
-Discuss the project on the community [Matrix channel](https://matrix.to/#/#helix-editor:matrix.org).
+Your question might already be answered on the [FAQ](https://github.com/helix-editor/helix/wiki/FAQ).
 
+Discuss the project on the community [Matrix Space](https://matrix.to/#/#helix-community:matrix.org) (make sure to join `#helix-editor:matrix.org` if you're on a client that doesn't support Matrix Spaces yet).
+
+# Credits
+
+Thanks to [@jakenvac](https://github.com/jakenvac) for designing the logo!

TODO.md

@@ -1,66 +0,0 @@
-- Refactor tree-sitter-highlight to work like the atom one, recomputing partial tree updates.
-- syntax errors highlight query
-
-------
-
-- tree sitter:
-  - lua
-  - markdown
-  - zig
-  - regex
-  - vue
-  - kotlin
-  - julia
-  - clojure
-  - erlang
-
-- [ ] use signature_help_provider and completion_provider trigger characters in
-    a hook to trigger signature help text / autocompletion
-- [ ] document.on_type provider triggers
-- [ ] completion isIncomplete support
-
-- [ ] extract indentation calculation queries so we can support other languages.
-
-1
-- [ ] :format/:fmt that formats the buffer
-- [ ] respect view fullscreen flag
-- [ ] Implement marks (superset of Selection/Range)
-
-- [ ] nixos packaging
-- [ ] CI binary builds
-
-- [ ] = for auto indent line/selection
-- [ ]  :x for closing buffers
-
-- [ ] repeat selection
-
-- [] jump to alt buffer
-
-- [ ] lsp: signature help
-- [x] lsp: hover
-- [ ] lsp: document symbols (nested/vec)
-- [ ] lsp: code actions
-- [ ] lsp: formatting
-- [x] lsp: goto
-
-- [ ] search: smart case by default: insensitive unless upper detected
-
-- [ ] move Compositor into tui
-
-2
-- [ ] surround bindings (select + surround ( wraps selection in parens )
-- [ ] macro recording
-- [ ] extend selection (treesitter select parent node) (replaces viw, vi(, va( etc )
-- [x] bracket pairs
-- [x] comment block (gcc)
-- [ ] selection align
-- [ ] store some state between restarts: file positions, prompt history
-- [ ] highlight matched characters in completion
-
-3
-- [ ] diff mode with highlighting?
-- [ ] snippet support (tab to jump between marks)
-- [ ] gamelisp/wasm scripting
-
-X
-- [ ] rendering via skulpin/skia or raw wgpu

base16_theme.toml

@@ -0,0 +1,51 @@
+# Author: NNB <nnbnh@protonmail.com>
+
+"ui.menu" = { fg = "black", bg = "white" }
+"ui.menu.selected" = { modifiers = ["reversed"] }
+"ui.linenr" = { fg = "gray", bg = "black" }
+"ui.popup" = { modifiers = ["reversed"] }
+"ui.linenr.selected" = { fg = "white", bg = "black", modifiers = ["bold"] }
+"ui.selection" = { fg = "black", bg = "blue" }
+"ui.selection.primary" = { fg = "white", bg = "blue" }
+"ui.text.inactive" = { fg = "gray" }
+"comment" = { fg = "gray" }
+"ui.statusline" = { fg = "black", bg = "white" }
+"ui.statusline.inactive" = { fg = "gray", bg = "white" }
+"ui.cursor" = { fg = "white", modifiers = ["reversed"] }
+"variable" = "red"
+"constant.numeric" = "yellow"
+"constant" = "yellow"
+"attributes" = "yellow"
+"type" = "yellow"
+"ui.cursor.match" = { fg = "yellow", modifiers = ["underlined"] }
+"string"  = "green"
+"variable.other.member" = "green"
+"constant.character.escape" = "cyan"
+"function" = "blue"
+"constructor" = "blue"
+"special" = "blue"
+"keyword" = "magenta"
+"label" = "magenta"
+"namespace" = "magenta"
+"ui.help" = { fg = "white", bg = "black" }
+
+"markup.heading" = "blue"
+"markup.list" = "red"
+"markup.bold" = { fg = "yellow", modifiers = ["bold"] }
+"markup.italic" = { fg = "magenta", modifiers = ["italic"] }
+"markup.link.url" = { fg = "yellow", modifiers = ["underlined"] }
+"markup.link.text" = "red"
+"markup.quote" = "cyan"
+"markup.raw" = "green"
+
+"diff.plus" = "green"
+"diff.delta" = "yellow"
+"diff.minus" = "red"
+
+"diagnostic" = { modifiers = ["underlined"] }
+"ui.gutter" = { bg = "black" }
+"info" = "blue"
+"hint" = "gray"
+"debug" = "gray"
+"warning" = "yellow"
+"error" = "red"

book/book.toml

@@ -3,4 +3,14 @@ authors = ["Blaž Hrastnik"]
 language = "en"
 multilingual = false
 src = "src"
-theme = "colibri"
+
+[output.html]
+cname = "docs.helix-editor.com"
+default-theme = "colibri"
+preferred-dark-theme = "colibri"
+git-repository-url = "https://github.com/helix-editor/helix"
+edit-url-template = "https://github.com/helix-editor/helix/edit/master/book/{path}"
+additional-css = ["custom.css"]
+
+[output.html.search]
+use-boolean-and = true

book/custom.css

@@ -0,0 +1,231 @@
+html {
+  font-family: "Inter", sans-serif;
+}
+
+.sidebar .sidebar-scrollbox {
+  padding: 0;
+}
+
+.chapter {
+  margin: 0.25rem 0;
+}
+
+.chapter li.chapter-item {
+  line-height: initial;
+  margin: 0;
+  padding: 1rem 1.5rem;
+}
+
+.chapter .section li.chapter-item {
+  line-height: inherit;
+  padding: .5rem .5rem 0 .5rem;
+}
+
+.content {
+  overflow-y: auto;
+  padding: 0 15px;
+  padding-bottom: 50px;
+}
+
+/* 2 1.75 1.5 1.25 1 .875 */
+.content h1 { font-size: 2em }
+.content h2 { font-size: 1.75em }
+.content h3 { font-size: 1.5em }
+.content h4 { font-size: 1.25em }
+.content h5 { font-size: 1em }
+.content h6 { font-size: .875em }
+
+.content h1,
+.content h2,
+.content h3,
+.content h4 {
+  font-weight: 500;
+  margin-top: 1.275em;
+  margin-bottom: .875em;
+}
+
+.content p,
+.content ol,
+.content ul,
+.content table {
+  margin-top: 0;
+  margin-bottom: .875em;
+}
+
+.content ul li {
+  margin-bottom: .25rem;
+}
+
+.content ul {
+  list-style-type: square;
+}
+
+.content ul ul,
+.content ol ul {
+  margin-bottom: .5rem;
+}
+
+.content li p {
+  margin-bottom: .5em;
+}
+
+blockquote {
+  margin: 1.5rem 0;
+  padding: 1rem 1.5rem;
+  color: var(--fg);
+  opacity: .9;
+  background-color: var(--quote-bg);
+  border-left: 4px solid var(--quote-border);
+  border-top: none;
+  border-bottom: none;
+}
+
+blockquote *:last-child {
+  margin-bottom: 0;
+}
+
+table {
+  width: 100%;
+}
+
+table thead th {
+  padding: .75rem;
+  text-align: left;
+  font-weight: 500;
+  line-height: 1.5;
+  width: auto;
+}
+
+table td {
+  padding: .75rem;
+  border: none;
+}
+
+table thead tr {
+  border: none;
+  border-bottom: 2px var(--table-border-color) solid;
+}
+
+table tbody tr {
+  border-bottom: 1px var(--table-border-line) solid;
+}
+
+table tbody tr:nth-child(2n) {
+  background: unset;
+}
+
+pre code.hljs {
+  display: block;
+  overflow-x: auto;
+  padding: 1em;
+}
+
+code.hljs {
+  padding: 3px 5px;
+}
+
+.colibri {
+  --bg: #3b224c;
+  --fg: #bcbdd0;
+  --heading-fg: #fff;
+
+  --sidebar-bg: #281733;
+  --sidebar-fg: #c8c9db;
+  --sidebar-non-existent: #505274;
+  --sidebar-active: #a4a0e8;
+  --sidebar-spacer: #2d334f;
+
+  --scrollbar: var(--sidebar-fg);
+
+  --icons: #737480;
+  --icons-hover: #b7b9cc;
+
+  /* --links: #a4a0e8; */
+  --links: #ECCDBA;
+
+  --inline-code-color: hsl(48.7, 7.8%, 70%);
+
+  --theme-popup-bg: #161923;
+  --theme-popup-border: #737480;
+  --theme-hover: rgba(0, 0, 0, .2);
+
+  --quote-bg: #281733;
+  --quote-border: hsl(226, 15%, 22%);
+
+  --table-border-color: hsl(226, 23%, 76%);
+  --table-header-bg: hsla(226, 23%, 31%, 0);
+  --table-alternate-bg: hsl(226, 23%, 14%);
+  --table-border-line: hsla(201deg, 20%, 92%, 0.2);
+
+  --searchbar-border-color: #aaa;
+  --searchbar-bg: #aeaec6;
+  --searchbar-fg: #000;
+  --searchbar-shadow-color: #aaa;
+  --searchresults-header-fg: #5f5f71;
+  --searchresults-border-color: #5c5c68;
+  --searchresults-li-bg: #242430;
+  --search-mark-bg: #a2cff5;
+}
+
+.colibri .content .header {
+  color: #fff;
+}
+
+/* highlight.js theme, :where() is used to avoid increasing specificity */
+
+:where(.colibri) .hljs {
+  background: #2f1e2e;
+  color: #a39e9b;
+}
+
+:where(.colibri) .hljs-comment,
+:where(.colibri) .hljs-quote {
+  color: #8d8687;
+}
+
+:where(.colibri) .hljs-link,
+:where(.colibri) .hljs-meta,
+:where(.colibri) .hljs-name,
+:where(.colibri) .hljs-regexp,
+:where(.colibri) .hljs-selector-class,
+:where(.colibri) .hljs-selector-id,
+:where(.colibri) .hljs-tag,
+:where(.colibri) .hljs-template-variable,
+:where(.colibri) .hljs-variable {
+  color: #ef6155;
+}
+
+:where(.colibri) .hljs-built_in,
+:where(.colibri) .hljs-deletion,
+:where(.colibri) .hljs-literal,
+:where(.colibri) .hljs-number,
+:where(.colibri) .hljs-params,
+:where(.colibri) .hljs-type {
+  color: #f99b15;
+}
+
+:where(.colibri) .hljs-attribute,
+:where(.colibri) .hljs-section,
+:where(.colibri) .hljs-title {
+  color: #fec418;
+}
+
+:where(.colibri) .hljs-addition,
+:where(.colibri) .hljs-bullet,
+:where(.colibri) .hljs-string,
+:where(.colibri) .hljs-symbol {
+  color: #48b685;
+}
+
+:where(.colibri) .hljs-keyword,
+:where(.colibri) .hljs-selector-tag {
+  color: #815ba4;
+}
+
+:where(.colibri) .hljs-emphasis {
+  font-style: italic;
+}
+
+:where(.colibri) .hljs-strong {
+  font-weight: 700;
+}

book/src/SUMMARY.md

@@ -1,7 +1,19 @@
 # Summary
 
+[Helix](./title-page.md)
+
 - [Installation](./install.md)
 - [Usage](./usage.md)
-- [Configuration](./configuration.md)
   - [Keymap](./keymap.md)
-  - [Hooks](./hooks.md)
+  - [Commands](./commands.md)
+  - [Language support](./lang-support.md)
+- [Migrating from Vim](./from-vim.md)
+- [Configuration](./configuration.md)
+  - [Themes](./themes.md)
+  - [Key remapping](./remapping.md)
+  - [Languages](./languages.md)
+- [Guides](./guides/README.md)
+  - [Adding languages](./guides/adding_languages.md)
+  - [Adding textobject queries](./guides/textobject.md)
+  - [Adding indent queries](./guides/indent.md)
+  - [Adding injection queries](./guides/injection.md)

book/src/commands.md

@@ -0,0 +1,5 @@
+# Commands
+
+Command mode can be activated by pressing `:`. The built-in commands are:
+
+{{#include ./generated/typable-cmd.md}}

book/src/configuration.md

@@ -1 +1,376 @@
 # Configuration
+
+To override global configuration parameters, create a `config.toml` file located in your config directory:
+
+- Linux and Mac: `~/.config/helix/config.toml`
+- Windows: `%AppData%\helix\config.toml`
+
+> 💡 You can easily open the config file by typing `:config-open` within Helix normal mode.
+
+Example config:
+
+```toml
+theme = "onedark"
+
+[editor]
+line-number = "relative"
+mouse = false
+
+[editor.cursor-shape]
+insert = "bar"
+normal = "block"
+select = "underline"
+
+[editor.file-picker]
+hidden = false
+```
+
+You can use a custom configuration file by specifying it with the `-c` or
+`--config` command line argument, for example `hx -c path/to/custom-config.toml`.
+Additionally, you can reload the configuration file by sending the USR1
+signal to the Helix process on Unix operating systems, such as by using the command `pkill -USR1 hx`.
+
+Finally, you can have a `config.toml` local to a project by putting it under a `.helix` directory in your repository.
+Its settings will be merged with the configuration directory `config.toml` and the built-in configuration.
+
+## Editor
+
+### `[editor]` Section
+
+| Key | Description | Default |
+|--|--|---------|
+| `scrolloff` | Number of lines of padding around the edge of the screen when scrolling | `5` |
+| `mouse` | Enable mouse mode | `true` |
+| `middle-click-paste` | Middle click paste support | `true` |
+| `scroll-lines` | Number of lines to scroll per scroll wheel step | `3` |
+| `shell` | Shell to use when running external commands | Unix: `["sh", "-c"]`<br/>Windows: `["cmd", "/C"]` |
+| `line-number` | Line number display: `absolute` simply shows each line's number, while `relative` shows the distance from the current line. When unfocused or in insert mode, `relative` will still show absolute line numbers | `absolute` |
+| `cursorline` | Highlight all lines with a cursor | `false` |
+| `cursorcolumn` | Highlight all columns with a cursor | `false` |
+| `gutters` | Gutters to display: Available are `diagnostics` and `diff` and `line-numbers` and `spacer`, note that `diagnostics` also includes other features like breakpoints, 1-width padding will be inserted if gutters is non-empty | `["diagnostics", "spacer", "line-numbers", "spacer", "diff"]` |
+| `auto-completion` | Enable automatic pop up of auto-completion | `true` |
+| `auto-format` | Enable automatic formatting on save | `true` |
+| `auto-save` | Enable automatic saving on the focus moving away from Helix. Requires [focus event support](https://github.com/helix-editor/helix/wiki/Terminal-Support) from your terminal | `false` |
+| `idle-timeout` | Time in milliseconds since last keypress before idle timers trigger. Used for autocompletion, set to 0 for instant | `250` |
+| `preview-completion-insert` | Whether to apply completion item instantly when selected | `true` |
+| `completion-trigger-len` | The min-length of word under cursor to trigger autocompletion | `2` |
+| `completion-replace` | Set to `true` to make completions always replace the entire word and not just the part before the cursor | `false` |
+| `auto-info` | Whether to display info boxes | `true` |
+| `true-color` | Set to `true` to override automatic detection of terminal truecolor support in the event of a false negative | `false` |
+| `undercurl` | Set to `true` to override automatic detection of terminal undercurl support in the event of a false negative | `false` |
+| `rulers` | List of column positions at which to display the rulers. Can be overridden by language specific `rulers` in `languages.toml` file | `[]` |
+| `bufferline` | Renders a line at the top of the editor displaying open buffers. Can be `always`, `never` or `multiple` (only shown if more than one buffer is in use) | `never` |
+| `color-modes` | Whether to color the mode indicator with different colors depending on the mode itself | `false` |
+| `text-width` | Maximum line length. Used for the `:reflow` command and soft-wrapping if `soft-wrap.wrap-at-text-width` is set | `80` |
+| `workspace-lsp-roots` | Directories relative to the workspace root that are treated as LSP roots. Should only be set in `.helix/config.toml` | `[]` |
+| `default-line-ending` | The line ending to use for new documents. Can be `native`, `lf`, `crlf`, `ff`, `cr` or `nel`. `native` uses the platform's native line ending (`crlf` on Windows, otherwise `lf`). | `native` |
+| `insert-final-newline` | Whether to automatically insert a trailing line-ending on write if missing | `true` |
+| `popup-border` | Draw border around `popup`, `menu`, `all`, or `none` | `none` |
+| `indent-heuristic` | How the indentation for a newly inserted line is computed: `simple` just copies the indentation level from the previous line, `tree-sitter` computes the indentation based on the syntax tree and `hybrid` combines both approaches. If the chosen heuristic is not available, a different one will be used as a fallback (the fallback order being `hybrid` -> `tree-sitter` -> `simple`). | `hybrid`
+
+### `[editor.statusline]` Section
+
+Allows configuring the statusline at the bottom of the editor.
+
+The configuration distinguishes between three areas of the status line:
+
+`[ ... ... LEFT ... ... | ... ... ... ... CENTER ... ... ... ... | ... ... RIGHT ... ... ]`
+
+Statusline elements can be defined as follows:
+
+```toml
+[editor.statusline]
+left = ["mode", "spinner"]
+center = ["file-name"]
+right = ["diagnostics", "selections", "position", "file-encoding", "file-line-ending", "file-type"]
+separator = "│"
+mode.normal = "NORMAL"
+mode.insert = "INSERT"
+mode.select = "SELECT"
+```
+The `[editor.statusline]` key takes the following sub-keys:
+
+| Key           | Description | Default |
+| ---           | ---         | ---     |
+| `left`        | A list of elements aligned to the left of the statusline | `["mode", "spinner", "file-name", "read-only-indicator", "file-modification-indicator"]` |
+| `center`      | A list of elements aligned to the middle of the statusline | `[]` |
+| `right`       | A list of elements aligned to the right of the statusline | `["diagnostics", "selections", "register", "position", "file-encoding"]` |
+| `separator`   | The character used to separate elements in the statusline | `"│"` |
+| `mode.normal` | The text shown in the `mode` element for normal mode | `"NOR"` |
+| `mode.insert` | The text shown in the `mode` element for insert mode | `"INS"` |
+| `mode.select` | The text shown in the `mode` element for select mode | `"SEL"` |
+
+The following statusline elements can be configured:
+
+| Key    | Description |
+| ------ | ----------- |
+| `mode` | The current editor mode (`mode.normal`/`mode.insert`/`mode.select`) |
+| `spinner` | A progress spinner indicating LSP activity |
+| `file-name` | The path/name of the opened file |
+| `file-base-name` | The basename of the opened file |
+| `file-modification-indicator` | The indicator to show whether the file is modified (a `[+]` appears when there are unsaved changes) |
+| `file-encoding` | The encoding of the opened file if it differs from UTF-8 |
+| `file-line-ending` | The file line endings (CRLF or LF) |
+| `read-only-indicator` | An indicator that shows `[readonly]` when a file cannot be written |
+| `total-line-numbers` | The total line numbers of the opened file |
+| `file-type` | The type of the opened file |
+| `diagnostics` | The number of warnings and/or errors |
+| `workspace-diagnostics` | The number of warnings and/or errors on workspace |
+| `selections` | The number of active selections |
+| `primary-selection-length` | The number of characters currently in primary selection |
+| `position` | The cursor position |
+| `position-percentage` | The cursor position as a percentage of the total number of lines |
+| `separator` | The string defined in `editor.statusline.separator` (defaults to `"│"`) |
+| `spacer` | Inserts a space between elements (multiple/contiguous spacers may be specified) |
+| `version-control` | The current branch name or detached commit hash of the opened workspace |
+| `register` | The current selected register |
+
+### `[editor.lsp]` Section
+
+| Key                   | Description                                                 | Default |
+| ---                   | -----------                                                 | ------- |
+| `enable`              | Enables LSP integration. Setting to false will completely disable language servers regardless of language settings.| `true` |
+| `display-messages`    | Display LSP progress messages below statusline[^1]          | `false` |
+| `auto-signature-help` | Enable automatic popup of signature help (parameter hints)  | `true`  |
+| `display-inlay-hints` | Display inlay hints[^2]                                     | `false` |
+| `display-signature-help-docs` | Display docs under signature help popup             | `true`  |
+| `snippets`      | Enables snippet completions. Requires a server restart (`:lsp-restart`) to take effect after `:config-reload`/`:set`. | `true`  |
+| `goto-reference-include-declaration` | Include declaration in the goto references popup. | `true`  |
+
+[^1]: By default, a progress spinner is shown in the statusline beside the file path.
+
+[^2]: You may also have to activate them in the LSP config for them to appear, not just in Helix. Inlay hints in Helix are still being improved on and may be a little bit laggy/janky under some circumstances. Please report any bugs you see so we can fix them!
+
+### `[editor.cursor-shape]` Section
+
+Defines the shape of cursor in each mode.
+Valid values for these options are `block`, `bar`, `underline`, or `hidden`.
+
+> 💡 Due to limitations of the terminal environment, only the primary cursor can
+> change shape.
+
+| Key      | Description                                | Default |
+| ---      | -----------                                | ------- |
+| `normal` | Cursor shape in [normal mode][normal mode] | `block` |
+| `insert` | Cursor shape in [insert mode][insert mode] | `block` |
+| `select` | Cursor shape in [select mode][select mode] | `block` |
+
+[normal mode]: ./keymap.md#normal-mode
+[insert mode]: ./keymap.md#insert-mode
+[select mode]: ./keymap.md#select--extend-mode
+
+### `[editor.file-picker]` Section
+
+Set options for file picker and global search. Ignoring a file means it is
+not visible in the Helix file picker and global search.
+
+All git related options are only enabled in a git repository.
+
+| Key | Description | Default |
+|--|--|---------|
+|`hidden` | Enables ignoring hidden files | `true`
+|`follow-symlinks` | Follow symlinks instead of ignoring them | `true`
+|`deduplicate-links` | Ignore symlinks that point at files already shown in the picker | `true`
+|`parents` | Enables reading ignore files from parent directories | `true`
+|`ignore` | Enables reading `.ignore` files | `true`
+|`git-ignore` | Enables reading `.gitignore` files | `true`
+|`git-global` | Enables reading global `.gitignore`, whose path is specified in git's config: `core.excludesfile` option | `true`
+|`git-exclude` | Enables reading `.git/info/exclude` files | `true`
+|`max-depth` | Set with an integer value for maximum depth to recurse | Defaults to `None`.
+
+Ignore files can be placed locally as `.ignore` or put in your home directory as `~/.ignore`. They support the usual ignore and negative ignore (unignore) rules used in `.gitignore` files.
+
+Additionally, you can use Helix-specific ignore files by creating a local `.helix/ignore` file in the current workspace or a global `ignore` file located in your Helix config directory:
+- Linux and Mac: `~/.config/helix/ignore`
+- Windows: `%AppData%\helix\ignore`
+
+Example:
+
+```ini
+# unignore in file picker and global search
+!.github/
+!.gitignore
+!.gitattributes
+```
+
+### `[editor.auto-pairs]` Section
+
+Enables automatic insertion of pairs to parentheses, brackets, etc. Can be a
+simple boolean value, or a specific mapping of pairs of single characters.
+
+To disable auto-pairs altogether, set `auto-pairs` to `false`:
+
+```toml
+[editor]
+auto-pairs = false # defaults to `true`
+```
+
+The default pairs are <code>(){}[]''""``</code>, but these can be customized by
+setting `auto-pairs` to a TOML table:
+
+```toml
+[editor.auto-pairs]
+'(' = ')'
+'{' = '}'
+'[' = ']'
+'"' = '"'
+'`' = '`'
+'<' = '>'
+```
+
+Additionally, this setting can be used in a language config. Unless
+the editor setting is `false`, this will override the editor config in
+documents with this language.
+
+Example `languages.toml` that adds <> and removes ''
+
+```toml
+[[language]]
+name = "rust"
+
+[language.auto-pairs]
+'(' = ')'
+'{' = '}'
+'[' = ']'
+'"' = '"'
+'`' = '`'
+'<' = '>'
+```
+
+### `[editor.search]` Section
+
+Search specific options.
+
+| Key | Description | Default |
+|--|--|---------|
+| `smart-case` | Enable smart case regex searching (case-insensitive unless pattern contains upper case characters) | `true` |
+| `wrap-around`| Whether the search should wrap after depleting the matches | `true` |
+
+### `[editor.whitespace]` Section
+
+Options for rendering whitespace with visible characters. Use `:set whitespace.render all` to temporarily enable visible whitespace.
+
+| Key | Description | Default |
+|-----|-------------|---------|
+| `render` | Whether to render whitespace. May either be `"all"` or `"none"`, or a table with sub-keys `space`, `nbsp`, `tab`, and `newline` | `"none"` |
+| `characters` | Literal characters to use when rendering whitespace. Sub-keys may be any of `tab`, `space`, `nbsp`, `newline` or `tabpad` | See example below |
+
+Example
+
+```toml
+[editor.whitespace]
+render = "all"
+# or control each character
+[editor.whitespace.render]
+space = "all"
+tab = "all"
+newline = "none"
+
+[editor.whitespace.characters]
+space = "·"
+nbsp = "⍽"
+tab = "→"
+newline = "⏎"
+tabpad = "·" # Tabs will look like "→···" (depending on tab width)
+```
+
+### `[editor.indent-guides]` Section
+
+Options for rendering vertical indent guides.
+
+| Key           | Description                                             | Default |
+| ---           | ---                                                     | ---     |
+| `render`      | Whether to render indent guides                         | `false` |
+| `character`   | Literal character to use for rendering the indent guide | `│`     |
+| `skip-levels` | Number of indent levels to skip                         | `0`     |
+
+Example:
+
+```toml
+[editor.indent-guides]
+render = true
+character = "╎" # Some characters that work well: "▏", "┆", "┊", "⸽"
+skip-levels = 1
+```
+
+### `[editor.gutters]` Section
+
+For simplicity, `editor.gutters` accepts an array of gutter types, which will
+use default settings for all gutter components.
+
+```toml
+[editor]
+gutters = ["diff", "diagnostics", "line-numbers", "spacer"]
+```
+
+To customize the behavior of gutters, the `[editor.gutters]` section must
+be used. This section contains top level settings, as well as settings for
+specific gutter components as subsections.
+
+| Key      | Description                    | Default                                                       |
+| ---      | ---                            | ---                                                           |
+| `layout` | A vector of gutters to display | `["diagnostics", "spacer", "line-numbers", "spacer", "diff"]` |
+
+Example:
+
+```toml
+[editor.gutters]
+layout = ["diff", "diagnostics", "line-numbers", "spacer"]
+```
+
+#### `[editor.gutters.line-numbers]` Section
+
+Options for the line number gutter
+
+| Key         | Description                             | Default |
+| ---         | ---                                     | ---     |
+| `min-width` | The minimum number of characters to use | `3`     |
+
+Example:
+
+```toml
+[editor.gutters.line-numbers]
+min-width = 1
+```
+
+#### `[editor.gutters.diagnostics]` Section
+
+Currently unused
+
+#### `[editor.gutters.diff]` Section
+
+Currently unused
+
+#### `[editor.gutters.spacer]` Section
+
+Currently unused
+
+### `[editor.soft-wrap]` Section
+
+Options for soft wrapping lines that exceed the view width:
+
+| Key                  | Description                                                  | Default |
+| ---                  | ---                                                          | ---     |
+| `enable`             | Whether soft wrapping is enabled.                            | `false` |
+| `max-wrap`           | Maximum free space left at the end of the line.              | `20`    |
+| `max-indent-retain`  | Maximum indentation to carry over when soft wrapping a line. | `40`    |
+| `wrap-indicator`     | Text inserted before soft wrapped lines, highlighted with `ui.virtual.wrap` | `↪ `    |
+| `wrap-at-text-width` | Soft wrap at `text-width` instead of using the full viewport size. | `false` |
+
+Example:
+
+```toml
+[editor.soft-wrap]
+enable = true
+max-wrap = 25 # increase value to reduce forced mid-word wrapping
+max-indent-retain = 0
+wrap-indicator = ""  # set wrap-indicator to "" to hide it
+```
+
+### `[editor.smart-tab]` Section
+
+
+| Key        | Description | Default |
+|------------|-------------|---------|
+| `enable` | If set to true, then when the cursor is in a position with non-whitespace to its left, instead of inserting a tab, it will run `move_parent_node_end`. If there is only whitespace to the left, then it inserts a tab as normal. With the default bindings, to explicitly insert a tab character, press Shift-tab. | `true` |
+| `supersede-menu` | Normally, when a menu is on screen, such as when auto complete is triggered, the tab key is bound to cycling through the items. This means when menus are on screen, one cannot use the tab key to trigger the `smart-tab` command. If this option is set to true, the `smart-tab` command always takes precedence, which means one cannot use the tab key to cycle through menu items. One of the other bindings must be used instead, such as arrow keys or `C-n`/`C-p`. | `false` |

book/src/from-vim.md

@@ -0,0 +1,12 @@
+# Migrating from Vim
+
+Helix's editing model is strongly inspired from Vim and Kakoune, and a notable
+difference from Vim (and the most striking similarity to Kakoune) is that Helix
+follows the `selection → action` model. This means that whatever you are
+going to act on (a word, a paragraph, a line, etc.) is selected first and the
+action itself (delete, change, yank, etc.) comes second. A cursor is simply a
+single width selection.
+
+See also Kakoune's [Migrating from Vim](https://github.com/mawww/kakoune/wiki/Migrating-from-Vim) and Helix's [Migrating from Vim](https://github.com/helix-editor/helix/wiki/Migrating-from-Vim).
+
+> TODO: Mention textobjects, surround, registers

book/src/generated/lang-support.md

@@ -0,0 +1,194 @@
+| Language | Syntax Highlighting | Treesitter Textobjects | Auto Indent | Default LSP |
+| --- | --- | --- | --- | --- |
+| agda | ✓ |  |  |  |
+| astro | ✓ |  |  |  |
+| awk | ✓ | ✓ |  | `awk-language-server` |
+| bash | ✓ | ✓ | ✓ | `bash-language-server` |
+| bass | ✓ |  |  | `bass` |
+| beancount | ✓ |  |  |  |
+| bibtex | ✓ |  |  | `texlab` |
+| bicep | ✓ |  |  | `bicep-langserver` |
+| blueprint | ✓ |  |  | `blueprint-compiler` |
+| c | ✓ | ✓ | ✓ | `clangd` |
+| c-sharp | ✓ | ✓ |  | `OmniSharp` |
+| cabal |  |  |  | `haskell-language-server-wrapper` |
+| cairo | ✓ | ✓ | ✓ | `cairo-language-server` |
+| capnp | ✓ |  | ✓ |  |
+| clojure | ✓ |  |  | `clojure-lsp` |
+| cmake | ✓ | ✓ | ✓ | `cmake-language-server` |
+| comment | ✓ |  |  |  |
+| common-lisp | ✓ |  | ✓ | `cl-lsp` |
+| cpon | ✓ |  | ✓ |  |
+| cpp | ✓ | ✓ | ✓ | `clangd` |
+| crystal | ✓ | ✓ |  | `crystalline` |
+| css | ✓ |  |  | `vscode-css-language-server` |
+| cue | ✓ |  |  | `cuelsp` |
+| d | ✓ | ✓ | ✓ | `serve-d` |
+| dart | ✓ |  | ✓ | `dart` |
+| dbml | ✓ |  |  |  |
+| devicetree | ✓ |  |  |  |
+| dhall | ✓ | ✓ |  | `dhall-lsp-server` |
+| diff | ✓ |  |  |  |
+| dockerfile | ✓ |  |  | `docker-langserver` |
+| dot | ✓ |  |  | `dot-language-server` |
+| dtd | ✓ |  |  |  |
+| edoc | ✓ |  |  |  |
+| eex | ✓ |  |  |  |
+| ejs | ✓ |  |  |  |
+| elixir | ✓ | ✓ | ✓ | `elixir-ls` |
+| elm | ✓ | ✓ |  | `elm-language-server` |
+| elvish | ✓ |  |  | `elvish` |
+| env | ✓ |  |  |  |
+| erb | ✓ |  |  |  |
+| erlang | ✓ | ✓ |  | `erlang_ls` |
+| esdl | ✓ |  |  |  |
+| fish | ✓ | ✓ | ✓ |  |
+| forth | ✓ |  |  | `forth-lsp` |
+| fortran | ✓ |  | ✓ | `fortls` |
+| fsharp | ✓ |  |  | `fsautocomplete` |
+| gas | ✓ | ✓ |  |  |
+| gdscript | ✓ | ✓ | ✓ |  |
+| gemini | ✓ |  |  |  |
+| git-attributes | ✓ |  |  |  |
+| git-commit | ✓ | ✓ |  |  |
+| git-config | ✓ |  |  |  |
+| git-ignore | ✓ |  |  |  |
+| git-rebase | ✓ |  |  |  |
+| gleam | ✓ | ✓ |  | `gleam` |
+| glsl | ✓ | ✓ | ✓ |  |
+| gn | ✓ |  |  |  |
+| go | ✓ | ✓ | ✓ | `gopls`, `golangci-lint-langserver` |
+| godot-resource | ✓ |  |  |  |
+| gomod | ✓ |  |  | `gopls` |
+| gotmpl | ✓ |  |  | `gopls` |
+| gowork | ✓ |  |  | `gopls` |
+| graphql | ✓ |  |  | `graphql-lsp` |
+| hare | ✓ |  |  |  |
+| haskell | ✓ | ✓ |  | `haskell-language-server-wrapper` |
+| haskell-persistent | ✓ |  |  |  |
+| hcl | ✓ |  | ✓ | `terraform-ls` |
+| heex | ✓ | ✓ |  | `elixir-ls` |
+| hocon | ✓ |  | ✓ |  |
+| hosts | ✓ |  |  |  |
+| html | ✓ |  |  | `vscode-html-language-server` |
+| hurl | ✓ |  | ✓ |  |
+| idris |  |  |  | `idris2-lsp` |
+| iex | ✓ |  |  |  |
+| ini | ✓ |  |  |  |
+| janet | ✓ |  |  |  |
+| java | ✓ | ✓ | ✓ | `jdtls` |
+| javascript | ✓ | ✓ | ✓ | `typescript-language-server` |
+| jinja | ✓ |  |  |  |
+| jsdoc | ✓ |  |  |  |
+| json | ✓ |  | ✓ | `vscode-json-language-server` |
+| json5 | ✓ |  |  |  |
+| jsonnet | ✓ |  |  | `jsonnet-language-server` |
+| jsx | ✓ | ✓ | ✓ | `typescript-language-server` |
+| julia | ✓ | ✓ | ✓ | `julia` |
+| just | ✓ | ✓ | ✓ |  |
+| kdl | ✓ | ✓ | ✓ |  |
+| kotlin | ✓ |  |  | `kotlin-language-server` |
+| latex | ✓ | ✓ |  | `texlab` |
+| lean | ✓ |  |  | `lean` |
+| ledger | ✓ |  |  |  |
+| llvm | ✓ | ✓ | ✓ |  |
+| llvm-mir | ✓ | ✓ | ✓ |  |
+| llvm-mir-yaml | ✓ |  | ✓ |  |
+| log | ✓ |  |  |  |
+| lpf | ✓ |  |  |  |
+| lua | ✓ | ✓ | ✓ | `lua-language-server` |
+| make | ✓ |  |  |  |
+| markdoc | ✓ |  |  | `markdoc-ls` |
+| markdown | ✓ |  |  | `marksman` |
+| markdown.inline | ✓ |  |  |  |
+| matlab | ✓ | ✓ | ✓ |  |
+| mermaid | ✓ |  |  |  |
+| meson | ✓ |  | ✓ |  |
+| mint |  |  |  | `mint` |
+| msbuild | ✓ |  | ✓ |  |
+| nasm | ✓ | ✓ |  |  |
+| nickel | ✓ |  | ✓ | `nls` |
+| nim | ✓ | ✓ | ✓ | `nimlangserver` |
+| nix | ✓ |  |  | `nil` |
+| nu | ✓ |  |  | `nu` |
+| nunjucks | ✓ |  |  |  |
+| ocaml | ✓ |  | ✓ | `ocamllsp` |
+| ocaml-interface | ✓ |  |  | `ocamllsp` |
+| odin | ✓ |  | ✓ | `ols` |
+| opencl | ✓ | ✓ | ✓ | `clangd` |
+| openscad | ✓ |  |  | `openscad-lsp` |
+| org | ✓ |  |  |  |
+| pascal | ✓ | ✓ |  | `pasls` |
+| passwd | ✓ |  |  |  |
+| pem | ✓ |  |  |  |
+| perl | ✓ | ✓ | ✓ | `perlnavigator` |
+| php | ✓ | ✓ | ✓ | `intelephense` |
+| po | ✓ | ✓ |  |  |
+| pod | ✓ |  |  |  |
+| ponylang | ✓ | ✓ | ✓ |  |
+| prisma | ✓ |  |  | `prisma-language-server` |
+| prolog |  |  |  | `swipl` |
+| protobuf | ✓ | ✓ | ✓ | `bufls`, `pb` |
+| prql | ✓ |  |  |  |
+| purescript | ✓ | ✓ |  | `purescript-language-server` |
+| python | ✓ | ✓ | ✓ | `pylsp` |
+| qml | ✓ |  | ✓ | `qmlls` |
+| r | ✓ |  |  | `R` |
+| racket | ✓ |  | ✓ | `racket` |
+| regex | ✓ |  |  |  |
+| rego | ✓ |  |  | `regols` |
+| rescript | ✓ | ✓ |  | `rescript-language-server` |
+| rmarkdown | ✓ |  | ✓ | `R` |
+| robot | ✓ |  |  | `robotframework_ls` |
+| ron | ✓ |  | ✓ |  |
+| rst | ✓ |  |  |  |
+| ruby | ✓ | ✓ | ✓ | `solargraph` |
+| rust | ✓ | ✓ | ✓ | `rust-analyzer` |
+| sage | ✓ | ✓ |  |  |
+| scala | ✓ | ✓ | ✓ | `metals` |
+| scheme | ✓ |  | ✓ |  |
+| scss | ✓ |  |  | `vscode-css-language-server` |
+| slint | ✓ |  | ✓ | `slint-lsp` |
+| smali | ✓ |  | ✓ |  |
+| smithy | ✓ |  |  | `cs` |
+| sml | ✓ |  |  |  |
+| solidity | ✓ |  |  | `solc` |
+| sql | ✓ |  |  |  |
+| sshclientconfig | ✓ |  |  |  |
+| starlark | ✓ | ✓ |  |  |
+| strace | ✓ |  |  |  |
+| svelte | ✓ |  | ✓ | `svelteserver` |
+| sway | ✓ | ✓ | ✓ | `forc` |
+| swift | ✓ |  |  | `sourcekit-lsp` |
+| t32 | ✓ |  |  |  |
+| tablegen | ✓ | ✓ | ✓ |  |
+| task | ✓ |  |  |  |
+| templ | ✓ |  |  | `templ` |
+| tfvars | ✓ |  | ✓ | `terraform-ls` |
+| todotxt | ✓ |  |  |  |
+| toml | ✓ |  |  | `taplo` |
+| tsq | ✓ |  |  |  |
+| tsx | ✓ | ✓ | ✓ | `typescript-language-server` |
+| twig | ✓ |  |  |  |
+| typescript | ✓ | ✓ | ✓ | `typescript-language-server` |
+| typst | ✓ |  |  | `typst-lsp` |
+| ungrammar | ✓ |  |  |  |
+| unison | ✓ |  |  |  |
+| uxntal | ✓ |  |  |  |
+| v | ✓ | ✓ | ✓ | `v-analyzer` |
+| vala | ✓ |  |  | `vala-language-server` |
+| verilog | ✓ | ✓ |  | `svlangserver` |
+| vhdl | ✓ |  |  | `vhdl_ls` |
+| vhs | ✓ |  |  |  |
+| vue | ✓ |  |  | `vue-language-server` |
+| wast | ✓ |  |  |  |
+| wat | ✓ |  |  |  |
+| webc | ✓ |  |  |  |
+| wgsl | ✓ |  |  | `wgsl_analyzer` |
+| wit | ✓ |  | ✓ |  |
+| wren | ✓ | ✓ | ✓ |  |
+| xit | ✓ |  |  |  |
+| xml | ✓ |  | ✓ |  |
+| yaml | ✓ |  | ✓ | `yaml-language-server`, `ansible-language-server` |
+| yuck | ✓ |  |  |  |
+| zig | ✓ | ✓ | ✓ | `zls` |

book/src/generated/typable-cmd.md

@@ -0,0 +1,88 @@
+| Name | Description |
+| --- | --- |
+| `:quit`, `:q` | Close the current view. |
+| `:quit!`, `:q!` | Force close the current view, ignoring unsaved changes. |
+| `:open`, `:o` | Open a file from disk into the current view. |
+| `:buffer-close`, `:bc`, `:bclose` | Close the current buffer. |
+| `:buffer-close!`, `:bc!`, `:bclose!` | Close the current buffer forcefully, ignoring unsaved changes. |
+| `:buffer-close-others`, `:bco`, `:bcloseother` | Close all buffers but the currently focused one. |
+| `:buffer-close-others!`, `:bco!`, `:bcloseother!` | Force close all buffers but the currently focused one. |
+| `:buffer-close-all`, `:bca`, `:bcloseall` | Close all buffers without quitting. |
+| `:buffer-close-all!`, `:bca!`, `:bcloseall!` | Force close all buffers ignoring unsaved changes without quitting. |
+| `:buffer-next`, `:bn`, `:bnext` | Goto next buffer. |
+| `:buffer-previous`, `:bp`, `:bprev` | Goto previous buffer. |
+| `:write`, `:w` | Write changes to disk. Accepts an optional path (:write some/path.txt) |
+| `:write!`, `:w!` | Force write changes to disk creating necessary subdirectories. Accepts an optional path (:write! some/path.txt) |
+| `:write-buffer-close`, `:wbc` | Write changes to disk and closes the buffer. Accepts an optional path (:write-buffer-close some/path.txt) |
+| `:write-buffer-close!`, `:wbc!` | Force write changes to disk creating necessary subdirectories and closes the buffer. Accepts an optional path (:write-buffer-close! some/path.txt) |
+| `:new`, `:n` | Create a new scratch buffer. |
+| `:format`, `:fmt` | Format the file using the LSP formatter. |
+| `:indent-style` | Set the indentation style for editing. ('t' for tabs or 1-16 for number of spaces.) |
+| `:line-ending` | Set the document's default line ending. Options: crlf, lf. |
+| `:earlier`, `:ear` | Jump back to an earlier point in edit history. Accepts a number of steps or a time span. |
+| `:later`, `:lat` | Jump to a later point in edit history. Accepts a number of steps or a time span. |
+| `:write-quit`, `:wq`, `:x` | Write changes to disk and close the current view. Accepts an optional path (:wq some/path.txt) |
+| `:write-quit!`, `:wq!`, `:x!` | Write changes to disk and close the current view forcefully. Accepts an optional path (:wq! some/path.txt) |
+| `:write-all`, `:wa` | Write changes from all buffers to disk. |
+| `:write-all!`, `:wa!` | Forcefully write changes from all buffers to disk creating necessary subdirectories. |
+| `:write-quit-all`, `:wqa`, `:xa` | Write changes from all buffers to disk and close all views. |
+| `:write-quit-all!`, `:wqa!`, `:xa!` | Write changes from all buffers to disk and close all views forcefully (ignoring unsaved changes). |
+| `:quit-all`, `:qa` | Close all views. |
+| `:quit-all!`, `:qa!` | Force close all views ignoring unsaved changes. |
+| `:cquit`, `:cq` | Quit with exit code (default 1). Accepts an optional integer exit code (:cq 2). |
+| `:cquit!`, `:cq!` | Force quit with exit code (default 1) ignoring unsaved changes. Accepts an optional integer exit code (:cq! 2). |
+| `:theme` | Change the editor theme (show current theme if no name specified). |
+| `:yank-join` | Yank joined selections. A separator can be provided as first argument. Default value is newline. |
+| `:clipboard-yank` | Yank main selection into system clipboard. |
+| `:clipboard-yank-join` | Yank joined selections into system clipboard. A separator can be provided as first argument. Default value is newline. |
+| `:primary-clipboard-yank` | Yank main selection into system primary clipboard. |
+| `:primary-clipboard-yank-join` | Yank joined selections into system primary clipboard. A separator can be provided as first argument. Default value is newline. |
+| `:clipboard-paste-after` | Paste system clipboard after selections. |
+| `:clipboard-paste-before` | Paste system clipboard before selections. |
+| `:clipboard-paste-replace` | Replace selections with content of system clipboard. |
+| `:primary-clipboard-paste-after` | Paste primary clipboard after selections. |
+| `:primary-clipboard-paste-before` | Paste primary clipboard before selections. |
+| `:primary-clipboard-paste-replace` | Replace selections with content of system primary clipboard. |
+| `:show-clipboard-provider` | Show clipboard provider name in status bar. |
+| `:change-current-directory`, `:cd` | Change the current working directory. |
+| `:show-directory`, `:pwd` | Show the current working directory. |
+| `:encoding` | Set encoding. Based on `https://encoding.spec.whatwg.org`. |
+| `:character-info`, `:char` | Get info about the character under the primary cursor. |
+| `:reload`, `:rl` | Discard changes and reload from the source file. |
+| `:reload-all`, `:rla` | Discard changes and reload all documents from the source files. |
+| `:update`, `:u` | Write changes only if the file has been modified. |
+| `:lsp-workspace-command` | Open workspace command picker |
+| `:lsp-restart` | Restarts the language servers used by the current doc |
+| `:lsp-stop` | Stops the language servers that are used by the current doc |
+| `:tree-sitter-scopes` | Display tree sitter scopes, primarily for theming and development. |
+| `:tree-sitter-highlight-name` | Display name of tree-sitter highlight scope under the cursor. |
+| `:debug-start`, `:dbg` | Start a debug session from a given template with given parameters. |
+| `:debug-remote`, `:dbg-tcp` | Connect to a debug adapter by TCP address and start a debugging session from a given template with given parameters. |
+| `:debug-eval` | Evaluate expression in current debug context. |
+| `:vsplit`, `:vs` | Open the file in a vertical split. |
+| `:vsplit-new`, `:vnew` | Open a scratch buffer in a vertical split. |
+| `:hsplit`, `:hs`, `:sp` | Open the file in a horizontal split. |
+| `:hsplit-new`, `:hnew` | Open a scratch buffer in a horizontal split. |
+| `:tutor` | Open the tutorial. |
+| `:goto`, `:g` | Goto line number. |
+| `:set-language`, `:lang` | Set the language of current buffer (show current language if no value specified). |
+| `:set-option`, `:set` | Set a config option at runtime.<br>For example to disable smart case search, use `:set search.smart-case false`. |
+| `:toggle-option`, `:toggle` | Toggle a boolean config option at runtime.<br>For example to toggle smart case search, use `:toggle search.smart-case`. |
+| `:get-option`, `:get` | Get the current value of a config option. |
+| `:sort` | Sort ranges in selection. |
+| `:rsort` | Sort ranges in selection in reverse order. |
+| `:reflow` | Hard-wrap the current selection of lines to a given width. |
+| `:tree-sitter-subtree`, `:ts-subtree` | Display tree sitter subtree under cursor, primarily for debugging queries. |
+| `:config-reload` | Refresh user config. |
+| `:config-open` | Open the user config.toml file. |
+| `:config-open-workspace` | Open the workspace config.toml file. |
+| `:log-open` | Open the helix log file. |
+| `:insert-output` | Run shell command, inserting output before each selection. |
+| `:append-output` | Run shell command, appending output after each selection. |
+| `:pipe` | Pipe each selection to the shell command. |
+| `:pipe-to` | Pipe each selection to the shell command, ignoring output. |
+| `:run-shell-command`, `:sh` | Run a shell command |
+| `:reset-diff-change`, `:diffget`, `:diffg` | Reset the diff change at the cursor position. |
+| `:clear-register` | Clear given register. If no argument is provided, clear all registers. |
+| `:redraw` | Clear and re-render the whole UI |
+| `:move` | Move the current buffer and its corresponding file to a different path |

book/src/guides/README.md

@@ -0,0 +1,4 @@
+# Guides
+
+This section contains guides for adding new language server configurations,
+tree-sitter grammars, textobject queries, and other similar items.

book/src/guides/adding_languages.md

@@ -0,0 +1,55 @@
+# Adding new languages to Helix
+
+In order to add a new language to Helix, you will need to follow the steps
+below.
+
+## Language configuration
+
+1. Add a new `[[language]]` entry in the `languages.toml` file and provide the
+   necessary configuration for the new language. For more information on
+   language configuration, refer to the
+   [language configuration section](../languages.md) of the documentation.
+   A new language server can be added by extending the `[language-server]` table in the same file.
+2. If you are adding a new language or updating an existing language server
+   configuration, run the command `cargo xtask docgen` to update the
+   [Language Support](../lang-support.md) documentation.
+
+> 💡 If you are adding a new Language Server configuration, make sure to update
+> the
+> [Language Server Wiki](https://github.com/helix-editor/helix/wiki/How-to-install-the-default-language-servers)
+> with the installation instructions.
+
+## Grammar configuration
+
+1. If a tree-sitter grammar is available for the new language, add a new
+   `[[grammar]]` entry to the `languages.toml` file.
+2. If you are testing the grammar locally, you can use the `source.path` key
+   with an absolute path to the grammar. However, before submitting a pull
+   request, make sure to switch to using `source.git`.
+
+## Queries
+
+1. In order to provide syntax highlighting and indentation for the new language,
+   you will need to add queries.
+2. Create a new directory for the language with the path
+   `runtime/queries/<name>/`.
+3. Refer to the
+   [tree-sitter website](https://tree-sitter.github.io/tree-sitter/syntax-highlighting#queries)
+   for more information on writing queries.
+4. A list of highlight captures can be found [on the themes page](https://docs.helix-editor.com/themes.html#scopes).
+
+> 💡 In Helix, the first matching query takes precedence when evaluating
+> queries, which is different from other editors such as Neovim where the last
+> matching query supersedes the ones before it. See
+> [this issue](https://github.com/helix-editor/helix/pull/1170#issuecomment-997294090)
+> for an example.
+
+## Common issues
+
+- If you encounter errors when running Helix after switching branches, you may
+  need to update the tree-sitter grammars. Run the command `hx --grammar fetch`
+  to fetch the grammars and `hx --grammar build` to build any out-of-date
+  grammars.
+- If a parser is causing a segfault, or you want to remove it, make sure to
+  remove the compiled parser located at `runtime/grammars/<name>.so`.
+- If you are attempting to add queries and Helix is unable to locate them, ensure that the environment variable `HELIX_RUNTIME` is set to the location of the `runtime` folder you're developing in.

book/src/guides/indent.md

@@ -0,0 +1,369 @@
+# Adding indent queries
+
+Helix uses tree-sitter to correctly indent new lines. This requires a tree-
+sitter grammar and an `indent.scm` query file placed in `runtime/queries/
+{language}/indents.scm`. The indentation for a line is calculated by traversing
+the syntax tree from the lowest node at the beginning of the new line (see
+[Indent queries](#indent-queries)). Each of these nodes contributes to the total
+indent when it is captured by the query (in what way depends on the name of
+the capture.
+
+Note that it matters where these added indents begin. For example,
+multiple indent level increases that start on the same line only increase
+the total indent level by 1. See [Capture types](#capture-types).
+
+By default, Helix uses the `hybrid` indentation heuristic. This means that
+indent queries are not used to compute the expected absolute indentation of a
+line but rather the expected difference in indentation between the new and an
+already existing line. This difference is then added to the actual indentation
+of the already existing line. Since this makes errors in the indent queries
+harder to find, it is recommended to disable it when testing via
+`:set indent-heuristic tree-sitter`. The rest of this guide assumes that
+the `tree-sitter` heuristic is used.
+
+## Indent queries
+
+When Helix is inserting a new line through `o`, `O`, or `<ret>`, to determine
+the indent level for the new line, the query in `indents.scm` is run on the
+document. The starting position of the query is the end of the line above where
+a new line will be inserted.
+
+For `o`, the inserted line is the line below the cursor, so that starting
+position of the query is the end of the current line.
+
+```rust
+fn need_hero(some_hero: Hero, life: Life) -> {
+    matches!(some_hero, Hero { // ←─────────────────╮
+        strong: true,//←╮  ↑  ↑                     │
+        fast: true,  // │  │  ╰── query start       │
+        sure: true,  // │  ╰───── cursor            ├─ traversal 
+        soon: true,  // ╰──────── new line inserted │  start node
+    }) &&            //                             │
+//  ↑                                               │
+//  ╰───────────────────────────────────────────────╯
+    some_hero > life
+}
+```
+
+For `O`, the newly inserted line is the *current* line, so the starting position
+of the query is the end of the line above the cursor.
+
+```rust
+fn need_hero(some_hero: Hero, life: Life) -> { // ←─╮
+    matches!(some_hero, Hero { // ←╮          ↑     │
+        strong: true,//    ↑   ╭───╯          │     │
+        fast: true,  //    │   │ query start ─╯     │
+        sure: true,  //    ╰───┼ cursor             ├─ traversal
+        soon: true,  //        ╰ new line inserted  │  start node
+    }) &&            //                             │
+    some_hero > life //                             │
+} // ←──────────────────────────────────────────────╯
+```
+
+From this starting node, the syntax tree is traversed up until the root node.
+Each indent capture is collected along the way, and then combined according to
+their [capture types](#capture-types) and [scopes](#scopes) to a final indent
+level for the line.
+
+### Capture types
+
+- `@indent` (default scope `tail`):
+  Increase the indent level by 1. Multiple occurrences in the same line *do not*
+  stack. If there is at least one `@indent` and one `@outdent` capture on the
+  same line, the indent level isn't changed at all.
+- `@outdent` (default scope `all`):
+  Decrease the indent level by 1. The same rules as for `@indent` apply.
+- `@indent.always` (default scope `tail`):
+  Increase the indent level by 1. Multiple occurrences on the same line *do*
+  stack. The final indent level is `@indent.always` – `@outdent.always`. If
+  an `@indent` and an `@indent.always` are on the same line, the `@indent` is
+  ignored.
+- `@outdent.always` (default scope `all`):
+  Decrease the indent level by 1. The same rules as for `@indent.always` apply.
+- `@align` (default scope `all`):
+  Align everything inside this node to some anchor. The anchor is given
+  by the start of the node captured by `@anchor` in the same pattern.
+  Every pattern with an `@align` should contain exactly one `@anchor`.
+  Indent (and outdent) for nodes below (in terms of their starting line)
+  the `@align` node is added to the indentation required for alignment.
+- `@extend`:
+  Extend the range of this node to the end of the line and to lines that are
+  indented more than the line that this node starts on. This is useful for
+  languages like Python, where for the purpose of indentation some nodes (like
+  functions or classes) should also contain indented lines that follow them.
+- `@extend.prevent-once`:
+  Prevents the first extension of an ancestor of this node. For example, in Python
+  a return expression always ends the block that it is in. Note that this only
+  stops the extension of the next `@extend` capture. If multiple ancestors are
+  captured, only the extension of the innermost one is prevented. All other
+  ancestors are unaffected (regardless of whether the innermost ancestor would
+  actually have been extended).
+
+#### `@indent` / `@outdent`
+
+Consider this example:
+
+```rust
+fn shout(things: Vec<Thing>) {
+    //                       ↑
+    //                       ├───────────────────────╮ indent level
+    //                    @indent                    ├┄┄┄┄┄┄┄┄┄┄┄┄┄┄
+    //                                               │
+    let it_all = |out| { things.filter(|thing| { //  │      1
+    //                 ↑                       ↑     │
+    //                 ├───────────────────────┼─────┼┄┄┄┄┄┄┄┄┄┄┄┄┄┄
+    //              @indent                 @indent  │
+    //                                               │      2
+        thing.can_do_with(out) //                    │
+    })}; //                                          ├┄┄┄┄┄┄┄┄┄┄┄┄┄┄
+  //↑↑↑                                              │      1
+} //╰┼┴──────────────────────────────────────────────┴┄┄┄┄┄┄┄┄┄┄┄┄┄┄
+// 3x @outdent
+```
+
+```scm
+((block) @indent)
+["}" ")"] @outdent
+```
+
+Note how on the second line, we have two blocks begin on the same line. In this
+case, since both captures occur on the same line, they are combined and only
+result in a net increase of 1. Also note that the closing `}`s are part of the
+`@indent` captures, but the 3 `@outdent`s also combine into 1 and result in that
+line losing one indent level.
+
+#### `@extend` / `@extend.prevent-once`
+
+For an example of where `@extend` can be useful, consider Python, which is
+whitespace-sensitive.
+
+```scm
+]
+  (parenthesized_expression)
+  (function_definition)
+  (class_definition)
+] @indent
+
+```
+
+```python
+class Hero:
+    def __init__(self, strong, fast, sure, soon):#  ←─╮
+        self.is_strong = strong #                     │
+        self.is_fast = fast     # ╭─── query start    │
+        self.is_sure = sure     # │ ╭─ cursor         │
+        self.is_soon = soon     # │ │                 │
+        #     ↑            ↑      │ │                 │
+        #     │            ╰──────╯ │                 │
+        #     ╰─────────────────────╯                 │
+        #                                             ├─ traversal
+    def need_hero(self, life):         #              │  start node
+        return (                       #              │
+            self.is_strong             #              │
+            and self.is_fast           #              │
+            and self.is_sure           #              │
+            and self.is_soon           #              │
+            and self > life            #              │
+        ) # ←─────────────────────────────────────────╯
+```
+
+Without braces to catch the scope of the function, the smallest descendant of
+the cursor on a line feed ends up being the entire inside of the class. Because
+of this, it will miss the entire function node and its indent capture, leading
+to an indent level one too small.
+
+To address this case, `@extend` tells helix to "extend" the captured node's span
+to the line feed and every consecutive line that has a greater indent level than
+the line of the node.
+
+```scm
+(parenthesized_expression) @indent
+
+]
+  (function_definition)
+  (class_definition)
+] @indent @extend
+
+```
+
+```python
+class Hero:
+    def __init__(self, strong, fast, sure, soon):#  ←─╮
+        self.is_strong = strong #                     │
+        self.is_fast = fast     # ╭─── query start    ├─ traversal
+        self.is_sure = sure     # │ ╭─ cursor         │  start node
+        self.is_soon = soon     # │ │ ←───────────────╯
+        #     ↑            ↑      │ │                 
+        #     │            ╰──────╯ │
+        #     ╰─────────────────────╯
+    def need_hero(self, life):
+        return (
+            self.is_strong
+            and self.is_fast
+            and self.is_sure
+            and self.is_soon
+            and self > life
+        )
+```
+
+Furthermore, there are some cases where extending to everything with a greater
+indent level may not be desirable. Consider the `need_hero` function above. If
+our cursor is on the last line of the returned expression.
+
+```python
+class Hero:
+    def __init__(self, strong, fast, sure, soon):
+        self.is_strong = strong
+        self.is_fast = fast
+        self.is_sure = sure
+        self.is_soon = soon
+
+    def need_hero(self, life):
+        return (
+            self.is_strong
+            and self.is_fast
+            and self.is_sure
+            and self.is_soon
+            and self > life
+        ) # ←─── cursor
+    #←────────── where cursor should go on new line
+```
+
+In Python, the are a few tokens that will always end a scope, such as a return
+statement. Since the scope ends, so should the indent level. But because the
+function span is extended to every line with a greater indent level, a new line
+would just continue on the same level. And an `@outdent` would not help us here
+either, since it would cause everything in the parentheses to become outdented
+as well.
+
+To help, we need to signal an end to the extension. We can do this with
+`@extend.prevent-once`.
+
+```scm
+(parenthesized_expression) @indent
+
+]
+  (function_definition)
+  (class_definition)
+] @indent @extend
+
+(return_statement) @extend.prevent-once
+```
+
+#### `@indent.always` / `@outdent.always`
+
+As mentioned before, normally if there is more than one `@indent` or `@outdent`
+capture on the same line, they are combined.
+
+Sometimes, there are cases when you may want to ensure that every indent capture
+is additive, regardless of how many occur on the same line. Consider this
+example in YAML.
+
+```yaml
+  - foo: bar
+# ↑ ↑
+# │ ╰─────────────── start of map
+# ╰───────────────── start of list element
+    baz: quux # ←─── cursor
+    # ←───────────── where the cursor should go on a new line
+    garply: waldo
+  - quux:
+      bar: baz
+    xyzzy: thud
+    fred: plugh
+```
+
+In YAML, you often have lists of maps. In these cases, the syntax is such that
+the list element and the map both start on the same line. But we really do want
+to start an indentation for each of these so that subsequent keys in the map
+hang over the list and align properly. This is where `@indent.always` helps.
+
+```scm
+((block_sequence_item) @item @indent.always @extend
+  (#not-one-line? @item))
+
+((block_mapping_pair
+    key: (_) @key
+    value: (_) @val
+    (#not-same-line? @key @val)
+  ) @indent.always @extend
+)
+```
+
+## Predicates
+
+In some cases, an S-expression cannot express exactly what pattern should be matched.
+For that, tree-sitter allows for predicates to appear anywhere within a pattern,
+similar to how `#set!` declarations work:
+
+```scm
+(some_kind
+  (child_kind) @indent
+  (#predicate? arg1 arg2 ...)
+)
+```
+
+The number of arguments depends on the predicate that's used.
+Each argument is either a capture (`@name`) or a string (`"some string"`).
+The following predicates are supported by tree-sitter:
+
+- `#eq?`/`#not-eq?`:
+The first argument (a capture) must/must not be equal to the second argument
+(a capture or a string).
+
+- `#match?`/`#not-match?`:
+The first argument (a capture) must/must not match the regex given in the
+second argument (a string).
+
+Additionally, we support some custom predicates for indent queries:
+
+- `#not-kind-eq?`:
+The kind of the first argument (a capture) must not be equal to the second
+argument (a string).
+
+- `#same-line?`/`#not-same-line?`:
+The captures given by the 2 arguments must/must not start on the same line.
+
+- `#one-line?`/`#not-one-line?`:
+The captures given by the fist argument must/must span a total of one line.
+
+### Scopes
+
+Added indents don't always apply to the whole node. For example, in most
+cases when a node should be indented, we actually only want everything
+except for its first line to be indented. For this, there are several
+scopes (more scopes may be added in the future if required):
+
+- `tail`:
+This scope applies to everything except for the first line of the
+captured node.
+- `all`:
+This scope applies to the whole captured node. This is only different from
+`tail` when the captured node is the first node on its line.
+
+For example, imagine we have the following function
+
+```rust
+fn aha() { // ←─────────────────────────────────────╮
+  let take = "on me";  // ←──────────────╮  scope:  │
+  let take = "me on";             //     ├─ "tail"  ├─ (block) @indent
+  let ill = be_gone_days(1 || 2); //     │          │
+} // ←───────────────────────────────────┴──────────┴─ "}" @outdent
+                                         //                scope: "all"
+```
+
+We can write the following query with the `#set!` declaration:
+
+  ```scm
+  ((block) @indent
+   (#set! "scope" "tail"))
+  ("}" @outdent
+   (#set! "scope" "all"))
+  ```
+
+As we can see, the "tail" scope covers the node, except for the first line.
+Everything up to and including the closing brace gets an indent level of 1.
+Then, on the closing brace, we encounter an outdent with a scope of "all", which
+means the first line is included, and the indent level is cancelled out on this
+line. (Note these scopes are the defaults for `@indent` and `@outdent`—they are
+written explicitly for demonstration.)

book/src/guides/injection.md

@@ -0,0 +1,57 @@
+# Adding Injection Queries
+
+Writing language injection queries allows one to highlight a specific node as a different language.
+In addition to the [standard][upstream-docs] language injection options used by tree-sitter, there
+are a few Helix specific extensions that allow for more control.
+
+And example of a simple query that would highlight all strings as bash in Nix:
+```scm
+((string_expression (string_fragment) @injection.content)
+  (#set! injection.language "bash"))
+```
+
+## Capture Types
+
+- `@injection.language` (standard):
+The captured node may contain the language name used to highlight the node captured by
+`@injection.content`.
+
+- `@injection.content` (standard):
+Marks the content to be highlighted as the language captured with `@injection.language` _et al_.
+
+- `@injection.filename` (extension):
+The captured node may contain a filename with a file-extension known to Helix,
+highlighting `@injection.content` as that language. This uses the language extensions defined in
+both the default languages.toml distributed with Helix, as well as user defined languages.
+
+- `@injection.shebang` (extension):
+The captured node may contain a shebang used to choose a language to highlight as. This also uses
+the shebangs defined in the default and user `languages.toml`.
+
+## Settings
+
+- `injection.combined` (standard):
+Indicates that all the matching nodes in the tree should have their content parsed as one
+nested document.
+
+- `injection.language` (standard):
+Forces the captured content to be highlighted as the given language
+
+- `injection.include-children` (standard):
+Indicates that the content node’s entire text should be re-parsed, including the text of its child
+nodes. By default, child nodes’ text will be excluded from the injected document.
+
+- `injection.include-unnamed-children` (extension):
+Same as `injection.include-children` but only for unnamed child nodes.
+
+## Predicates
+
+- `#eq?` (standard):
+The first argument (a capture) must be equal to the second argument
+(a capture or a string).
+
+- `#match?` (standard):
+The first argument (a capture) must match the regex given in the
+second argument (a string).
+
+[upstream-docs]: http://tree-sitter.github.io/tree-sitter/syntax-highlighting#language-injection

book/src/guides/textobject.md

@@ -0,0 +1,47 @@
+# Adding textobject queries
+
+Helix supports textobjects that are language specific, such as functions, classes, etc.
+These textobjects require an accompanying tree-sitter grammar and a `textobjects.scm` query file
+to work properly. Tree-sitter allows us to query the source code syntax tree
+and capture specific parts of it. The queries are written in a lisp dialect.
+More information on how to write queries can be found in the [official tree-sitter
+documentation][tree-sitter-queries].
+
+Query files should be placed in `runtime/queries/{language}/textobjects.scm`
+when contributing to Helix. Note that to test the query files locally you should put
+them under your local runtime directory (`~/.config/helix/runtime` on Linux
+for example).
+
+The following [captures][tree-sitter-captures] are recognized:
+
+| Capture Name       |
+| ---                |
+| `function.inside`  |
+| `function.around`  |
+| `class.inside`     |
+| `class.around`     |
+| `test.inside`      |
+| `test.around`      |
+| `parameter.inside` |
+| `comment.inside`   |
+| `comment.around`   |
+
+[Example query files][textobject-examples] can be found in the helix GitHub repository.
+
+## Queries for textobject based navigation
+
+Tree-sitter based navigation in Helix is done using captures in the
+following order:
+
+- `object.movement`
+- `object.around`
+- `object.inside`
+
+For example if a `function.around` capture has been already defined for a language
+in its `textobjects.scm` file, function navigation should also work automatically.
+`function.movement` should be defined only if the node captured by `function.around`
+doesn't make sense in a navigation context.
+
+[tree-sitter-queries]: https://tree-sitter.github.io/tree-sitter/using-parsers#query-syntax
+[tree-sitter-captures]: https://tree-sitter.github.io/tree-sitter/using-parsers#capturing-nodes
+[textobject-examples]: https://github.com/search?q=repo%3Ahelix-editor%2Fhelix+filename%3Atextobjects.scm&type=Code&ref=advsearch&l=&l=

book/src/hooks.md

@@ -1 +0,0 @@
-# Hooks

book/src/install.md

@@ -1,38 +1,322 @@
-# Installation
+# Installing Helix
 
-We provide pre-built binaries on the [GitHub Releases page](https://github.com/helix-editor/helix/releases).
+<!--toc:start-->
+- [Pre-built binaries](#pre-built-binaries)
+- [Linux, macOS, Windows and OpenBSD packaging status](#linux-macos-windows-and-openbsd-packaging-status)
+- [Linux](#linux)
+  - [Ubuntu](#ubuntu)
+  - [Fedora/RHEL](#fedorarhel)
+  - [Arch Linux extra](#arch-linux-extra)
+  - [NixOS](#nixos)
+  - [Flatpak](#flatpak)
+  - [Snap](#snap)
+  - [AppImage](#appimage)
+- [macOS](#macos)
+  - [Homebrew Core](#homebrew-core)
+  - [MacPorts](#macports)
+- [Windows](#windows)
+  - [Winget](#winget)
+  - [Scoop](#scoop)
+  - [Chocolatey](#chocolatey)
+  - [MSYS2](#msys2)
+- [Building from source](#building-from-source)
+  - [Configuring Helix's runtime files](#configuring-helixs-runtime-files)
+    - [Linux and macOS](#linux-and-macos)
+    - [Windows](#windows)
+    - [Multiple runtime directories](#multiple-runtime-directories)
+  - [Validating the installation](#validating-the-installation)
+  - [Configure the desktop shortcut](#configure-the-desktop-shortcut)
+<!--toc:end-->
 
-## OSX
+To install Helix, follow the instructions specific to your operating system.
+Note that:
 
-TODO: brew tap
+- To get the latest nightly version of Helix, you need to
+  [build from source](#building-from-source).
 
-```
-$ brew tap helix-editor/helix
-$ brew install helix
-```
+- To take full advantage of Helix, install the language servers for your
+  preferred programming languages. See the
+  [wiki](https://github.com/helix-editor/helix/wiki/How-to-install-the-default-language-servers)
+  for instructions.
+
+## Pre-built binaries
+
+Download pre-built binaries from the
+[GitHub Releases page](https://github.com/helix-editor/helix/releases). Add the binary to your system's `$PATH` to use it from the command
+line.
+
+## Linux, macOS, Windows and OpenBSD packaging status
+
+[![Packaging status](https://repology.org/badge/vertical-allrepos/helix.svg)](https://repology.org/project/helix/versions)
 
 ## Linux
 
+The following third party repositories are available:
+
+### Ubuntu
+
+Add the `PPA` for Helix:
+
+```sh
+sudo add-apt-repository ppa:maveonair/helix-editor
+sudo apt update
+sudo apt install helix
+```
+
+### Fedora/RHEL
+
+```sh
+sudo dnf install helix
+```
+
+### Arch Linux extra
+
+Releases are available in the `extra` repository:
+
+```sh
+sudo pacman -S helix
+```
+Additionally, a [helix-git](https://aur.archlinux.org/packages/helix-git/) package is available
+in the AUR, which builds the master branch.
+
 ### NixOS
 
-A [flake](https://nixos.wiki/wiki/Flakes) containing the package is available in
-the project root. The flake can also be used to spin up a reproducible development
-shell for working on Helix.
+Helix is available in [nixpkgs](https://github.com/nixos/nixpkgs) through the `helix` attribute,
+the unstable channel usually carries the latest release.
 
-### Arch Linux
+Helix is also available as a [flake](https://nixos.wiki/wiki/Flakes) in the project
+root. Use `nix develop` to spin up a reproducible development shell. Outputs are
+cached for each push to master using [Cachix](https://www.cachix.org/). The
+flake is configured to automatically make use of this cache assuming the user
+accepts the new settings on first use.
 
-TODO: AUR
+If you are using a version of Nix without flakes enabled,
+[install Cachix CLI](https://docs.cachix.org/installation) and use
+`cachix use helix` to configure Nix to use cached outputs when possible.
 
-## Build from source
+### Flatpak
 
-```
-git clone --recurse-submodules --shallow-submodules -j8 https://github.com/helix-editor/helix
-cd helix
-cargo install --path helix-term
+Helix is available on [Flathub](https://flathub.org/en-GB/apps/com.helix_editor.Helix):
+
+```sh
+flatpak install flathub com.helix_editor.Helix
+flatpak run com.helix_editor.Helix
 ```
 
-This will install the `hx` binary to `$HOME/.cargo/bin`.
+### Snap
 
-Now copy the `runtime/` directory somewhere. Helix will by default look for the
-runtime inside the same folder as the executable, but that can be overriden via
-the `HELIX_RUNTIME` environment variable.
+Helix is available on [Snapcraft](https://snapcraft.io/helix) and can be installed with:
+
+```sh
+snap install --classic helix
+```
+
+This will install Helix as both `/snap/bin/helix` and `/snap/bin/hx`, so make sure `/snap/bin` is in your `PATH`.
+
+### AppImage
+
+Install Helix using the Linux [AppImage](https://appimage.org/) format.
+Download the official Helix AppImage from the [latest releases](https://github.com/helix-editor/helix/releases/latest) page.
+
+```sh
+chmod +x helix-*.AppImage # change permission for executable mode
+./helix-*.AppImage # run helix
+```
+ 
+## macOS
+
+### Homebrew Core
+
+```sh
+brew install helix
+```
+
+### MacPorts
+
+```sh
+port install helix
+```
+
+## Windows
+
+Install on Windows using [Winget](https://learn.microsoft.com/en-us/windows/package-manager/winget/), [Scoop](https://scoop.sh/), [Chocolatey](https://chocolatey.org/)
+or [MSYS2](https://msys2.org/).
+
+### Winget
+Windows Package Manager winget command-line tool is by default available on Windows 11 and modern versions of Windows 10 as a part of the App Installer.
+You can get [App Installer from the Microsoft Store](https://www.microsoft.com/p/app-installer/9nblggh4nns1#activetab=pivot:overviewtab). If it's already installed, make sure it is updated with the latest version.
+
+```sh
+winget install Helix.Helix
+```
+
+### Scoop
+
+```sh
+scoop install helix
+```
+
+### Chocolatey
+
+```sh
+choco install helix
+```
+
+### MSYS2
+
+For 64-bit Windows 8.1 or above:
+
+```sh
+pacman -S mingw-w64-ucrt-x86_64-helix
+```
+
+## Building from source
+
+Requirements:
+
+Clone the Helix GitHub repository into a directory of your choice. The
+examples in this documentation assume installation into either `~/src/` on
+Linux and macOS, or `%userprofile%\src\` on Windows.
+
+- The [Rust toolchain](https://www.rust-lang.org/tools/install)
+- The [Git version control system](https://git-scm.com/)
+- A C++14 compatible compiler to build the tree-sitter grammars, for example GCC or Clang
+
+If you are using the `musl-libc` standard library instead of `glibc` the following environment variable must be set during the build to ensure tree-sitter grammars can be loaded correctly:
+
+```sh
+RUSTFLAGS="-C target-feature=-crt-static"
+```
+
+1. Clone the repository:
+
+   ```sh
+   git clone https://github.com/helix-editor/helix
+   cd helix
+   ```
+
+2. Compile from source:
+
+   ```sh
+   cargo install --path helix-term --locked
+   ```
+
+   This command will create the `hx` executable and construct the tree-sitter
+   grammars in the local `runtime` folder.
+
+> 💡 If you do not want to fetch or build grammars, set an environment variable `HELIX_DISABLE_AUTO_GRAMMAR_BUILD`
+
+> 💡 Tree-sitter grammars can be fetched and compiled if not pre-packaged. Fetch
+> grammars with `hx --grammar fetch` and compile them with
+> `hx --grammar build`. This will install them in
+> the `runtime` directory within the user's helix config directory (more
+> [details below](#multiple-runtime-directories)).
+
+### Configuring Helix's runtime files
+
+#### Linux and macOS
+
+The **runtime** directory is one below the Helix source, so either set a
+`HELIX_RUNTIME` environment variable to point to that directory and add it to
+your `~/.bashrc` or equivalent:
+
+```sh
+HELIX_RUNTIME=~/src/helix/runtime
+```
+
+Or, create a symbolic link:
+
+```sh
+ln -Ts $PWD/runtime ~/.config/helix/runtime
+```
+
+If the above command fails to create a symbolic link because the file exists either move `~/.config/helix/runtime` to a new location or delete it, then run the symlink command above again.
+
+#### Windows
+
+Either set the `HELIX_RUNTIME` environment variable to point to the runtime files using the Windows setting (search for
+`Edit environment variables for your account`) or use the `setx` command in
+Cmd:
+
+```sh
+setx HELIX_RUNTIME "%userprofile%\source\repos\helix\runtime"
+```
+
+> 💡 `%userprofile%` resolves to your user directory like
+> `C:\Users\Your-Name\` for example.
+
+Or, create a symlink in `%appdata%\helix\` that links to the source code directory:
+
+| Method     | Command                                                                                |
+| ---------- | -------------------------------------------------------------------------------------- |
+| PowerShell | `New-Item -ItemType Junction -Target "runtime" -Path "$Env:AppData\helix\runtime"`     |
+| Cmd        | `cd %appdata%\helix` <br/> `mklink /D runtime "%userprofile%\src\helix\runtime"`       |
+
+> 💡 On Windows, creating a symbolic link may require running PowerShell or
+> Cmd as an administrator.
+
+#### Multiple runtime directories
+
+When Helix finds multiple runtime directories it will search through them for files in the
+following order:
+
+1. `runtime/` sibling directory to `$CARGO_MANIFEST_DIR` directory (this is intended for
+  developing and testing helix only).
+2. `runtime/` subdirectory of OS-dependent helix user config directory.
+3. `$HELIX_RUNTIME`
+4. Distribution-specific fallback directory (set at compile time—not run time—
+   with the `HELIX_DEFAULT_RUNTIME` environment variable)
+5. `runtime/` subdirectory of path to Helix executable.
+
+This order also sets the priority for selecting which file will be used if multiple runtime
+directories have files with the same name.
+
+#### Note to packagers
+
+If you are making a package of Helix for end users, to provide a good out of
+the box experience, you should set the `HELIX_DEFAULT_RUNTIME` environment
+variable at build time (before invoking `cargo build`) to a directory which
+will store the final runtime files after installation. For example, say you want
+to package the runtime into `/usr/lib/helix/runtime`. The rough steps a build
+script could follow are:
+
+1. `export HELIX_DEFAULT_RUNTIME=/usr/lib/helix/runtime`
+1. `cargo build --profile opt --locked --path helix-term`
+1. `cp -r runtime $BUILD_DIR/usr/lib/helix/`
+1. `cp target/opt/hx $BUILD_DIR/usr/bin/hx`
+
+This way the resulting `hx` binary will always look for its runtime directory in
+`/usr/lib/helix/runtime` if the user has no custom runtime in `~/.config/helix`
+or `HELIX_RUNTIME`.
+
+### Validating the installation
+
+To make sure everything is set up as expected you should run the Helix health
+check:
+
+```sh
+hx --health
+```
+
+For more information on the health check results refer to
+[Health check](https://github.com/helix-editor/helix/wiki/Healthcheck).
+
+### Configure the desktop shortcut
+
+If your desktop environment supports the
+[XDG desktop menu](https://specifications.freedesktop.org/menu-spec/menu-spec-latest.html)
+you can configure Helix to show up in the application menu by copying the
+provided `.desktop` and icon files to their correct folders:
+
+```sh
+cp contrib/Helix.desktop ~/.local/share/applications
+cp contrib/helix.png ~/.icons # or ~/.local/share/icons
+```
+
+To use another terminal than the system default, you can modify the `.desktop`
+file. For example, to use `kitty`:
+
+```sh
+sed -i "s|Exec=hx %F|Exec=kitty hx %F|g" ~/.local/share/applications/Helix.desktop
+sed -i "s|Terminal=true|Terminal=false|g" ~/.local/share/applications/Helix.desktop
+```

book/src/keymap.md

@@ -1,141 +1,454 @@
 # Keymap
 
+- [Normal mode](#normal-mode)
+  - [Movement](#movement)
+  - [Changes](#changes)
+    - [Shell](#shell)
+  - [Selection manipulation](#selection-manipulation)
+  - [Search](#search)
+  - [Minor modes](#minor-modes)
+    - [View mode](#view-mode)
+    - [Goto mode](#goto-mode)
+    - [Match mode](#match-mode)
+    - [Window mode](#window-mode)
+    - [Space mode](#space-mode)
+      - [Popup](#popup)
+    - [Unimpaired](#unimpaired)
+- [Insert mode](#insert-mode)
+- [Select / extend mode](#select--extend-mode)
+- [Picker](#picker)
+- [Prompt](#prompt)
+
+> 💡 Mappings marked (**LSP**) require an active language server for the file.
+
+> 💡 Mappings marked (**TS**) require a tree-sitter grammar for the file type.
+
 ## Normal mode
 
+Normal mode is the default mode when you launch helix. You can return to it from other modes by pressing the `Escape` key.
+
 ### Movement
 
-| Key | Description |
-|-----|-----------|
-| h   | move left |
-| j   | move down |
-| k   | move up |
-| l   | move right |
-| w   | move next word start |
-| b   | move previous word start |
-| e   | move next word end |
-| t   | find 'till next char |
-| f   | find next char |
-| T   | find 'till previous char |
-| F   | find previous char |
-| 0   | move to the start of the line |
-| $   | move to the end of the line |
-| m   | Jump to matching bracket | 
-| PageUp | Move page up |
-| PageDown | Move page down |
-| ctrl-u | Move half page up |
-| ctrl-d | Move half page down |
-| Tab | Switch to next view |
-| ctrl-i | Jump forward on the jumplist TODO: conflicts tab |
-| ctrl-o | Jump backward on the jumplist |
-| v   | Enter select (extend) mode |
-| g   | Enter goto mode |
-| :   | Enter command mode |
-| z   | Enter view mode |
-| space   | Enter space mode |
-| K | Show documentation for the item under the cursor |
+> NOTE: Unlike Vim, `f`, `F`, `t` and `T` are not confined to the current line.
+
+| Key                   | Description                                        | Command                     |
+| -----                 | -----------                                        | -------                     |
+| `h`, `Left`           | Move left                                          | `move_char_left`            |
+| `j`, `Down`           | Move down                                          | `move_visual_line_down`     |
+| `k`, `Up`             | Move up                                            | `move_visual_line_up`       |
+| `l`, `Right`          | Move right                                         | `move_char_right`           |
+| `w`                   | Move next word start                               | `move_next_word_start`      |
+| `b`                   | Move previous word start                           | `move_prev_word_start`      |
+| `e`                   | Move next word end                                 | `move_next_word_end`        |
+| `W`                   | Move next WORD start                               | `move_next_long_word_start` |
+| `B`                   | Move previous WORD start                           | `move_prev_long_word_start` |
+| `E`                   | Move next WORD end                                 | `move_next_long_word_end`   |
+| `t`                   | Find 'till next char                               | `find_till_char`            |
+| `f`                   | Find next char                                     | `find_next_char`            |
+| `T`                   | Find 'till previous char                           | `till_prev_char`            |
+| `F`                   | Find previous char                                 | `find_prev_char`            |
+| `G`                   | Go to line number `<n>`                            | `goto_line`                 |
+| `Alt-.`               | Repeat last motion (`f`, `t` or `m`)               | `repeat_last_motion`        |
+| `Home`                | Move to the start of the line                      | `goto_line_start`           |
+| `End`                 | Move to the end of the line                        | `goto_line_end`             |
+| `Ctrl-b`, `PageUp`    | Move page up                                       | `page_up`                   |
+| `Ctrl-f`, `PageDown`  | Move page down                                     | `page_down`                 |
+| `Ctrl-u`              | Move half page up                                  | `half_page_up`              |
+| `Ctrl-d`              | Move half page down                                | `half_page_down`            |
+| `Ctrl-i`              | Jump forward on the jumplist                       | `jump_forward`              |
+| `Ctrl-o`              | Jump backward on the jumplist                      | `jump_backward`             |
+| `Ctrl-s`              | Save the current selection to the jumplist         | `save_selection`            |
 
 ### Changes
 
-| Key | Description |
-|-----|-----------|
-| r   | replace (single character change) |
-| i   | Insert before selection |
-| a   | Insert after selection (append) |
-| I   | Insert at the start of the line | 
-| A   | Insert at the end of the line | 
-| o   | Open new line below selection | 
-| o   | Open new line above selection | 
-| u   | Undo change |
-| U   | Redo change |
-| y   | Yank selection |
-| p   | Paste after selection |
-| P   | Paste before selection |
-| >   | Indent selection |
-| <   | Unindent selection |
-| =   | Format selection |
-| d   | Delete selection | 
-| c   | Change selection (delete and enter insert mode) | 
+| Key         | Description                                                          | Command                   |
+| -----       | -----------                                                          | -------                   |
+| `r`         | Replace with a character                                             | `replace`                 |
+| `R`         | Replace with yanked text                                             | `replace_with_yanked`     |
+| `~`         | Switch case of the selected text                                     | `switch_case`             |
+| `` ` ``     | Set the selected text to lower case                                  | `switch_to_lowercase`     |
+| `` Alt-` `` | Set the selected text to upper case                                  | `switch_to_uppercase`     |
+| `i`         | Insert before selection                                              | `insert_mode`             |
+| `a`         | Insert after selection (append)                                      | `append_mode`             |
+| `I`         | Insert at the start of the line                                      | `insert_at_line_start`    |
+| `A`         | Insert at the end of the line                                        | `insert_at_line_end`      |
+| `o`         | Open new line below selection                                        | `open_below`              |
+| `O`         | Open new line above selection                                        | `open_above`              |
+| `.`         | Repeat last insert                                                   | N/A                       |
+| `u`         | Undo change                                                          | `undo`                    |
+| `U`         | Redo change                                                          | `redo`                    |
+| `Alt-u`     | Move backward in history                                             | `earlier`                 |
+| `Alt-U`     | Move forward in history                                              | `later`                   |
+| `y`         | Yank selection                                                       | `yank`                    |
+| `p`         | Paste after selection                                                | `paste_after`             |
+| `P`         | Paste before selection                                               | `paste_before`            |
+| `"` `<reg>` | Select a register to yank to or paste from                           | `select_register`         |
+| `>`         | Indent selection                                                     | `indent`                  |
+| `<`         | Unindent selection                                                   | `unindent`                |
+| `=`         | Format selection (currently nonfunctional/disabled) (**LSP**)        | `format_selections`       |
+| `d`         | Delete selection                                                     | `delete_selection`        |
+| `Alt-d`     | Delete selection, without yanking                                    | `delete_selection_noyank` |
+| `c`         | Change selection (delete and enter insert mode)                      | `change_selection`        |
+| `Alt-c`     | Change selection (delete and enter insert mode, without yanking)     | `change_selection_noyank` |
+| `Ctrl-a`    | Increment object (number) under cursor                               | `increment`               |
+| `Ctrl-x`    | Decrement object (number) under cursor                               | `decrement`               |
+| `Q`         | Start/stop macro recording to the selected register (experimental)   | `record_macro`            |
+| `q`         | Play back a recorded macro from the selected register (experimental) | `replay_macro`            |
+
+#### Shell
+
+| Key     | Description                                                                      | Command               |
+| ------  | -----------                                                                      | -------               |
+| <code>&#124;</code>     | Pipe each selection through shell command, replacing with output                 | `shell_pipe`          |
+| <code>Alt-&#124;</code> | Pipe each selection into shell command, ignoring output                          | `shell_pipe_to`       |
+| `!`     | Run shell command, inserting output before each selection                        | `shell_insert_output` |
+| `Alt-!` | Run shell command, appending output after each selection                         | `shell_append_output` |
+| `$`     | Pipe each selection into shell command, keep selections where command returned 0 | `shell_keep_pipe`     |
+
 
 ### Selection manipulation
 
-| Key | Description |
-|-----|-----------|
-| s   | Select all regex matches inside selections | 
-| S   | Split selection into subselections on regex matches | 
-| alt-s   | Split selection on newlines | 
-| ;   | Collapse selection onto a single cursor | 
-| alt-;   | Flip selection cursor and anchor | 
-| %   | Select entire file | 
-| x   | Select current line | 
-| X   | Extend to next line | 
-| [   | Expand selection to parent syntax node TODO: pick a key | 
-| J | join lines inside selection |
-| K | keep selections matching the regex TODO: overlapped by hover help |
-| space | keep only the primary selection TODO: overlapped by space mode |
-| ctrl-c | Comment/uncomment the selections | 
+| Key                   | Description                                                       | Command                              |
+| -----                 | -----------                                                       | -------                              |
+| `s`                   | Select all regex matches inside selections                        | `select_regex`                       |
+| `S`                   | Split selection into sub selections on regex matches              | `split_selection`                    |
+| `Alt-s`               | Split selection on newlines                                       | `split_selection_on_newline`         |
+| `Alt-minus`           | Merge selections                                                  | `merge_selections`                   |
+| `Alt-_`               | Merge consecutive selections                                      | `merge_consecutive_selections`       |
+| `&`                   | Align selection in columns                                        | `align_selections`                   |
+| `_`                   | Trim whitespace from the selection                                | `trim_selections`                    |
+| `;`                   | Collapse selection onto a single cursor                           | `collapse_selection`                 |
+| `Alt-;`               | Flip selection cursor and anchor                                  | `flip_selections`                    |
+| `Alt-:`               | Ensures the selection is in forward direction                     | `ensure_selections_forward`          |
+| `,`                   | Keep only the primary selection                                   | `keep_primary_selection`             |
+| `Alt-,`               | Remove the primary selection                                      | `remove_primary_selection`           |
+| `C`                   | Copy selection onto the next line (Add cursor below)              | `copy_selection_on_next_line`        |
+| `Alt-C`               | Copy selection onto the previous line (Add cursor above)          | `copy_selection_on_prev_line`        |
+| `(`                   | Rotate main selection backward                                    | `rotate_selections_backward`         |
+| `)`                   | Rotate main selection forward                                     | `rotate_selections_forward`          |
+| `Alt-(`               | Rotate selection contents backward                                | `rotate_selection_contents_backward` |
+| `Alt-)`               | Rotate selection contents forward                                 | `rotate_selection_contents_forward`  |
+| `%`                   | Select entire file                                                | `select_all`                         |
+| `x`                   | Select current line, if already selected, extend to next line     | `extend_line_below`                  |
+| `X`                   | Extend selection to line bounds (line-wise selection)             | `extend_to_line_bounds`              |
+| `Alt-x`               | Shrink selection to line bounds (line-wise selection)             | `shrink_to_line_bounds`              |
+| `J`                   | Join lines inside selection                                       | `join_selections`                    |
+| `Alt-J`               | Join lines inside selection and select the inserted space         | `join_selections_space`              |
+| `K`                   | Keep selections matching the regex                                | `keep_selections`                    |
+| `Alt-K`               | Remove selections matching the regex                              | `remove_selections`                  |
+| `Ctrl-c`              | Comment/uncomment the selections                                  | `toggle_comments`                    |
+| `Alt-o`, `Alt-up`     | Expand selection to parent syntax node (**TS**)                   | `expand_selection`                   |
+| `Alt-i`, `Alt-down`   | Shrink syntax tree object selection (**TS**)                      | `shrink_selection`                   |
+| `Alt-p`, `Alt-left`   | Select previous sibling node in syntax tree (**TS**)              | `select_prev_sibling`                |
+| `Alt-n`, `Alt-right`  | Select next sibling node in syntax tree (**TS**)                  | `select_next_sibling`                |
 
 ### Search
 
-> TODO: The search implementation isn't ideal yet -- we don't support searching
-in reverse, or searching via smartcase.
+Search commands all operate on the `/` register by default. To use a different register, use `"<char>`.
 
-| Key | Description |
-|-----|-----------|
-| /   | Search for regex pattern | 
-| n   | Select next search match | 
-| N   | Add next search match to selection | 
-| *   | Use current selection as the search pattern | 
+| Key   | Description                                 | Command              |
+| ----- | -----------                                 | -------              |
+| `/`   | Search for regex pattern                    | `search`             |
+| `?`   | Search for previous pattern                 | `rsearch`            |
+| `n`   | Select next search match                    | `search_next`        |
+| `N`   | Select previous search match                | `search_prev`        |
+| `*`   | Use current selection as the search pattern | `search_selection`   |
 
-## Select / extend mode
+### Minor modes
 
-I'm still pondering whether to keep this mode or not. It changes movement
-commands to extend the existing selection instead of replacing it.
+These sub-modes are accessible from normal mode and typically switch back to normal mode after a command.
 
-> NOTE: It's a bit confusing at the moment because extend hasn't been
-> implemented for all movement commands yet.
+| Key      | Description                                        | Command        |
+| -----    | -----------                                        | -------        |
+| `v`      | Enter [select (extend) mode](#select--extend-mode) | `select_mode`  |
+| `g`      | Enter [goto mode](#goto-mode)                      | N/A            |
+| `m`      | Enter [match mode](#match-mode)                    | N/A            |
+| `:`      | Enter command mode                                 | `command_mode` |
+| `z`      | Enter [view mode](#view-mode)                      | N/A            |
+| `Z`      | Enter sticky [view mode](#view-mode)               | N/A            |
+| `Ctrl-w` | Enter [window mode](#window-mode)                  | N/A            |
+| `Space`  | Enter [space mode](#space-mode)                    | N/A            |
 
-## View mode
+These modes (except command mode) can be configured by
+[remapping keys](https://docs.helix-editor.com/remapping.html#minor-modes).
+
+#### View mode
+
+Accessed by typing `z` in [normal mode](#normal-mode).
 
 View mode is intended for scrolling and manipulating the view without changing
-the selection.
+the selection. The "sticky" variant of this mode (accessed by typing `Z` in
+normal mode) is persistent and can be exited using the escape key. This is
+useful when you're simply looking over text and not actively editing it.
 
-| Key | Description |
-|-----|-----------|
-| z , c | Vertically center the line |
-| t   | Align the line to the top of the screen |
-| b   | Align the line to the bottom of the screen |
-| m   | Align the line to the middle of the screen (horizontally) |
-| j   | Scroll the view downwards |
-| k   | Scroll the view upwards |
 
-## Goto mode
+| Key                  | Description                                               | Command             |
+| -----                | -----------                                               | -------             |
+| `z`, `c`             | Vertically center the line                                | `align_view_center` |
+| `t`                  | Align the line to the top of the screen                   | `align_view_top`    |
+| `b`                  | Align the line to the bottom of the screen                | `align_view_bottom` |
+| `m`                  | Align the line to the middle of the screen (horizontally) | `align_view_middle` |
+| `j`, `down`          | Scroll the view downwards                                 | `scroll_down`       |
+| `k`, `up`            | Scroll the view upwards                                   | `scroll_up`         |
+| `Ctrl-f`, `PageDown` | Move page down                                            | `page_down`         |
+| `Ctrl-b`, `PageUp`   | Move page up                                              | `page_up`           |
+| `Ctrl-d`             | Move half page down                                       | `half_page_down`    |
+| `Ctrl-u`             | Move half page up                                         | `half_page_up`      |
+
+#### Goto mode
+
+Accessed by typing `g` in [normal mode](#normal-mode).
 
 Jumps to various locations.
 
-> NOTE: Some of these features are only available with the LSP present.
+| Key   | Description                                      | Command                    |
+| ----- | -----------                                      | -------                    |
+| `g`   | Go to line number `<n>` else start of file       | `goto_file_start`          |
+| `e`   | Go to the end of the file                        | `goto_last_line`           |
+| `f`   | Go to files in the selections                    | `goto_file`                |
+| `h`   | Go to the start of the line                      | `goto_line_start`          |
+| `l`   | Go to the end of the line                        | `goto_line_end`            |
+| `s`   | Go to first non-whitespace character of the line | `goto_first_nonwhitespace` |
+| `t`   | Go to the top of the screen                      | `goto_window_top`          |
+| `c`   | Go to the middle of the screen                   | `goto_window_center`       |
+| `b`   | Go to the bottom of the screen                   | `goto_window_bottom`       |
+| `d`   | Go to definition (**LSP**)                       | `goto_definition`          |
+| `y`   | Go to type definition (**LSP**)                  | `goto_type_definition`     |
+| `r`   | Go to references (**LSP**)                       | `goto_reference`           |
+| `i`   | Go to implementation (**LSP**)                   | `goto_implementation`      |
+| `a`   | Go to the last accessed/alternate file           | `goto_last_accessed_file`  |
+| `m`   | Go to the last modified/alternate file           | `goto_last_modified_file`  |
+| `n`   | Go to next buffer                                | `goto_next_buffer`         |
+| `p`   | Go to previous buffer                            | `goto_previous_buffer`     |
+| `.`   | Go to last modification in current file          | `goto_last_modification`   |
+| `j`   | Move down textual (instead of visual) line       | `move_line_down`           |
+| `k`   | Move up textual (instead of visual) line         | `move_line_up`             |
 
-| Key | Description |
-|-----|-----------|
-| g   | Go to the start of the file |
-| e   | Go to the end of the file |
-| e   | Go to definition |
-| t   | Go to type definition |
-| r   | Go to references |
-| i   | Go to implementation |
+#### Match mode
 
-## Object mode
+Accessed by typing `m` in [normal mode](#normal-mode).
+
+See the relevant section in [Usage](./usage.md) for an explanation about
+[surround](./usage.md#surround) and [textobject](./usage.md#navigating-using-tree-sitter-textobjects) usage.
+
+| Key              | Description                                     | Command                    |
+| -----            | -----------                                     | -------                    |
+| `m`              | Goto matching bracket (**TS**)                  | `match_brackets`           |
+| `s` `<char>`     | Surround current selection with `<char>`        | `surround_add`             |
+| `r` `<from><to>` | Replace surround character `<from>` with `<to>` | `surround_replace`         |
+| `d` `<char>`     | Delete surround character `<char>`              | `surround_delete`          |
+| `a` `<object>`   | Select around textobject                        | `select_textobject_around` |
+| `i` `<object>`   | Select inside textobject                        | `select_textobject_inner`  |
 
 TODO: Mappings for selecting syntax nodes (a superset of `[`).
 
-## Space mode
+#### Window mode
 
-This layer is a kludge of mappings I had under leader key in neovim.
+Accessed by typing `Ctrl-w` in [normal mode](#normal-mode).
 
-| Key | Description |
-|-----|-----------|
-| f   | Open file picker |
-| b   | Open buffer picker |
-| v   | Open a new vertical split into the current file |
-| w   | Save changes to file |
-| c   | Close the current split |
-| space   | Keep primary selection TODO: it's here because space mode replaced it |
+This layer is similar to Vim keybindings as Kakoune does not support windows.
+
+| Key                    | Description                                          | Command           |
+| -----                  | -------------                                        | -------           |
+| `w`, `Ctrl-w`          | Switch to next window                                | `rotate_view`     |
+| `v`, `Ctrl-v`          | Vertical right split                                 | `vsplit`          |
+| `s`, `Ctrl-s`          | Horizontal bottom split                              | `hsplit`          |
+| `f`                    | Go to files in the selections in horizontal splits   | `goto_file`       |
+| `F`                    | Go to files in the selections in vertical splits     | `goto_file`       |
+| `h`, `Ctrl-h`, `Left`  | Move to left split                                   | `jump_view_left`  |
+| `j`, `Ctrl-j`, `Down`  | Move to split below                                  | `jump_view_down`  |
+| `k`, `Ctrl-k`, `Up`    | Move to split above                                  | `jump_view_up`    |
+| `l`, `Ctrl-l`, `Right` | Move to right split                                  | `jump_view_right` |
+| `q`, `Ctrl-q`          | Close current window                                 | `wclose`          |
+| `o`, `Ctrl-o`          | Only keep the current window, closing all the others | `wonly`           |
+| `H`                    | Swap window to the left                              | `swap_view_left`  |
+| `J`                    | Swap window downwards                                | `swap_view_down`  |
+| `K`                    | Swap window upwards                                  | `swap_view_up`    |
+| `L`                    | Swap window to the right                             | `swap_view_right` |
+
+#### Space mode
+
+Accessed by typing `Space` in [normal mode](#normal-mode).
+
+This layer is a kludge of mappings, mostly pickers.
+
+| Key     | Description                                                             | Command                                    |
+| -----   | -----------                                                             | -------                                    |
+| `f`     | Open file picker                                                        | `file_picker`                              |
+| `F`     | Open file picker at current working directory                           | `file_picker_in_current_directory`         |
+| `b`     | Open buffer picker                                                      | `buffer_picker`                            |
+| `j`     | Open jumplist picker                                                    | `jumplist_picker`                          |
+| `g`     | Debug (experimental)                                                    | N/A                                        |
+| `k`     | Show documentation for item under cursor in a [popup](#popup) (**LSP**) | `hover`                                    |
+| `s`     | Open document symbol picker (**LSP**)                                   | `symbol_picker`                            |
+| `S`     | Open workspace symbol picker (**LSP**)                                  | `workspace_symbol_picker`                  |
+| `d`     | Open document diagnostics picker (**LSP**)                              | `diagnostics_picker`                       |
+| `D`     | Open workspace diagnostics picker (**LSP**)                             | `workspace_diagnostics_picker`             |
+| `r`     | Rename symbol (**LSP**)                                                 | `rename_symbol`                            |
+| `a`     | Apply code action (**LSP**)                                             | `code_action`                              |
+| `h`     | Select symbol references (**LSP**)                                      | `select_references_to_symbol_under_cursor` |
+| `'`     | Open last fuzzy picker                                                  | `last_picker`                              |
+| `w`     | Enter [window mode](#window-mode)                                       | N/A                                        |
+| `p`     | Paste system clipboard after selections                                 | `paste_clipboard_after`                    |
+| `P`     | Paste system clipboard before selections                                | `paste_clipboard_before`                   |
+| `y`     | Yank selections to clipboard                                            | `yank_to_clipboard`                        |
+| `Y`     | Yank main selection to clipboard                                        | `yank_main_selection_to_clipboard`         |
+| `R`     | Replace selections by clipboard contents                                | `replace_selections_with_clipboard`        |
+| `/`     | Global search in workspace folder                                       | `global_search`                            |
+| `?`     | Open command palette                                                    | `command_palette`                          |
+
+> 💡 Global search displays results in a fuzzy picker, use `Space + '` to bring it back up after opening a file.
+
+##### Popup
+
+Displays documentation for item under cursor.
+
+| Key      | Description |
+| ----     | ----------- |
+| `Ctrl-u` | Scroll up   |
+| `Ctrl-d` | Scroll down |
+
+#### Unimpaired
+
+These mappings are in the style of [vim-unimpaired](https://github.com/tpope/vim-unimpaired).
+
+| Key      | Description                                  | Command               |
+| -----    | -----------                                  | -------               |
+| `]d`     | Go to next diagnostic (**LSP**)              | `goto_next_diag`      |
+| `[d`     | Go to previous diagnostic (**LSP**)          | `goto_prev_diag`      |
+| `]D`     | Go to last diagnostic in document (**LSP**)  | `goto_last_diag`      |
+| `[D`     | Go to first diagnostic in document (**LSP**) | `goto_first_diag`     |
+| `]f`     | Go to next function (**TS**)                 | `goto_next_function`  |
+| `[f`     | Go to previous function (**TS**)             | `goto_prev_function`  |
+| `]t`     | Go to next type definition (**TS**)          | `goto_next_class`     |
+| `[t`     | Go to previous type definition (**TS**)      | `goto_prev_class`     |
+| `]a`     | Go to next argument/parameter (**TS**)       | `goto_next_parameter` |
+| `[a`     | Go to previous argument/parameter (**TS**)   | `goto_prev_parameter` |
+| `]c`     | Go to next comment (**TS**)                  | `goto_next_comment`   |
+| `[c`     | Go to previous comment (**TS**)              | `goto_prev_comment`   |
+| `]T`     | Go to next test (**TS**)                     | `goto_next_test`      |
+| `[T`     | Go to previous test (**TS**)                 | `goto_prev_test`      |
+| `]p`     | Go to next paragraph                         | `goto_next_paragraph` |
+| `[p`     | Go to previous paragraph                     | `goto_prev_paragraph` |
+| `]g`     | Go to next change                            | `goto_next_change`    |
+| `[g`     | Go to previous change                        | `goto_prev_change`    |
+| `]G`     | Go to last change                            | `goto_last_change`    |
+| `[G`     | Go to first change                           | `goto_first_change`   |
+| `]Space` | Add newline below                            | `add_newline_below`   |
+| `[Space` | Add newline above                            | `add_newline_above`   |
+
+## Insert mode
+
+Accessed by typing `i` in [normal mode](#normal-mode).
+
+Insert mode bindings are minimal by default. Helix is designed to
+be a modal editor, and this is reflected in the user experience and internal
+mechanics. Changes to the text are only saved for undos when
+escaping from insert mode to normal mode.
+
+> 💡 New users are strongly encouraged to learn the modal editing paradigm
+> to get the smoothest experience.
+
+| Key                                         | Description                 | Command                  |
+| -----                                       | -----------                 | -------                  |
+| `Escape`                                    | Switch to normal mode       | `normal_mode`            |
+| `Ctrl-s`                                    | Commit undo checkpoint      | `commit_undo_checkpoint` |
+| `Ctrl-x`                                    | Autocomplete                | `completion`             |
+| `Ctrl-r`                                    | Insert a register content   | `insert_register`        |
+| `Ctrl-w`, `Alt-Backspace`                   | Delete previous word        | `delete_word_backward`   |
+| `Alt-d`, `Alt-Delete`                       | Delete next word            | `delete_word_forward`    |
+| `Ctrl-u`                                    | Delete to start of line     | `kill_to_line_start`     |
+| `Ctrl-k`                                    | Delete to end of line       | `kill_to_line_end`       |
+| `Ctrl-h`, `Backspace`, `Shift-Backspace`    | Delete previous char        | `delete_char_backward`   |
+| `Ctrl-d`, `Delete`                          | Delete next char            | `delete_char_forward`    |
+| `Ctrl-j`, `Enter`                           | Insert new line             | `insert_newline`         |
+
+These keys are not recommended, but are included for new users less familiar
+with modal editors.
+
+| Key                                         | Description                 | Command                  |
+| -----                                       | -----------                 | -------                  |
+| `Up`                                        | Move to previous line       | `move_line_up`           |
+| `Down`                                      | Move to next line           | `move_line_down`         |
+| `Left`                                      | Backward a char             | `move_char_left`         |
+| `Right`                                     | Forward a char              | `move_char_right`        |
+| `PageUp`                                    | Move one page up            | `page_up`                |
+| `PageDown`                                  | Move one page down          | `page_down`              |
+| `Home`                                      | Move to line start          | `goto_line_start`        |
+| `End`                                       | Move to line end            | `goto_line_end_newline`  |
+
+As you become more comfortable with modal editing, you may want to disable some
+insert mode bindings. You can do this by editing your `config.toml` file.
+
+```toml
+[keys.insert]
+up = "no_op"
+down = "no_op"
+left = "no_op"
+right = "no_op"
+pageup = "no_op"
+pagedown = "no_op"
+home = "no_op"
+end = "no_op"
+```
+
+## Select / extend mode
+
+Accessed by typing `v` in [normal mode](#normal-mode).
+
+Select mode echoes Normal mode, but changes any movements to extend
+selections rather than replace them. Goto motions are also changed to
+extend, so that `vgl`, for example, extends the selection to the end of
+the line.
+
+Search is also affected. By default, `n` and `N` will remove the current
+selection and select the next instance of the search term. Toggling this
+mode before pressing `n` or `N` makes it possible to keep the current
+selection. Toggling it on and off during your iterative searching allows
+you to selectively add search terms to your selections.
+
+## Picker
+
+Keys to use within picker. Remapping currently not supported.
+
+| Key                          | Description                                                |
+| -----                        | -------------                                              |
+| `Shift-Tab`, `Up`, `Ctrl-p`  | Previous entry                                             |
+| `Tab`, `Down`, `Ctrl-n`      | Next entry                                                 |
+| `PageUp`, `Ctrl-u`           | Page up                                                    |
+| `PageDown`, `Ctrl-d`         | Page down                                                  |
+| `Home`                       | Go to first entry                                          |
+| `End`                        | Go to last entry                                           |
+| `Enter`                      | Open selected                                              |
+| `Alt-Enter`                  | Open selected in the background without closing the picker |
+| `Ctrl-s`                     | Open horizontally                                          |
+| `Ctrl-v`                     | Open vertically                                            |
+| `Ctrl-t`                     | Toggle preview                                             |
+| `Escape`, `Ctrl-c`           | Close picker                                               |
+
+## Prompt
+
+Keys to use within prompt, Remapping currently not supported.
+
+| Key                                         | Description                                                             |
+| -----                                       | -------------                                                           |
+| `Escape`, `Ctrl-c`                          | Close prompt                                                            |
+| `Alt-b`, `Ctrl-Left`                        | Backward a word                                                         |
+| `Ctrl-b`, `Left`                            | Backward a char                                                         |
+| `Alt-f`, `Ctrl-Right`                       | Forward a word                                                          |
+| `Ctrl-f`, `Right`                           | Forward a char                                                          |
+| `Ctrl-e`, `End`                             | Move prompt end                                                         |
+| `Ctrl-a`, `Home`                            | Move prompt start                                                       |
+| `Ctrl-w`, `Alt-Backspace`, `Ctrl-Backspace` | Delete previous word                                                    |
+| `Alt-d`, `Alt-Delete`, `Ctrl-Delete`        | Delete next word                                                        |
+| `Ctrl-u`                                    | Delete to start of line                                                 |
+| `Ctrl-k`                                    | Delete to end of line                                                   |
+| `Backspace`, `Ctrl-h`, `Shift-Backspace`    | Delete previous char                                                    |
+| `Delete`, `Ctrl-d`                          | Delete next char                                                        |
+| `Ctrl-s`                                    | Insert a word under doc cursor, may be changed to Ctrl-r Ctrl-w later   |
+| `Ctrl-p`, `Up`                              | Select previous history                                                 |
+| `Ctrl-n`, `Down`                            | Select next history                                                     |
+| `Ctrl-r`                                    | Insert the content of the register selected by following input char     |
+| `Tab`                                       | Select next completion item                                             |
+| `BackTab`                                   | Select previous completion item                                         |
+| `Enter`                                     | Open selected                                                           |

book/src/lang-support.md

@@ -0,0 +1,16 @@
+# Language Support
+
+The following languages and Language Servers are supported. To use
+Language Server features, you must first [install][lsp-install-wiki] the
+appropriate Language Server.
+
+You can check the language support in your installed helix version with `hx --health`.
+
+Also see the [Language Configuration][lang-config] docs and the [Adding
+Languages][adding-languages] guide for more language configuration information.
+
+{{#include ./generated/lang-support.md}}
+
+[lsp-install-wiki]: https://github.com/helix-editor/helix/wiki/How-to-install-the-default-language-servers
+[lang-config]: ./languages.md
+[adding-languages]: ./guides/adding_languages.md

book/src/languages.md

@@ -0,0 +1,237 @@
+# Languages
+
+Language-specific settings and settings for language servers are configured
+in `languages.toml` files.
+
+## `languages.toml` files
+
+There are three possible locations for a `languages.toml` file:
+
+1. In the Helix source code, which lives in the
+   [Helix repository](https://github.com/helix-editor/helix/blob/master/languages.toml).
+   It provides the default configurations for languages and language servers.
+
+2. In your [configuration directory](./configuration.md). This overrides values
+   from the built-in language configuration. For example, to disable
+   auto-LSP-formatting in Rust:
+
+   ```toml
+   # in <config_dir>/helix/languages.toml
+
+   [language-server.mylang-lsp]
+   command = "mylang-lsp"
+
+   [[language]]
+   name = "rust"
+   auto-format = false
+   ```
+
+3. In a `.helix` folder in your project. Language configuration may also be
+   overridden local to a project by creating a `languages.toml` file in a
+   `.helix` folder. Its settings will be merged with the language configuration
+   in the configuration directory and the built-in configuration.
+
+## Language configuration
+
+Each language is configured by adding a `[[language]]` section to a
+`languages.toml` file. For example:
+
+```toml
+[[language]]
+name = "mylang"
+scope = "source.mylang"
+injection-regex = "mylang"
+file-types = ["mylang", "myl"]
+comment-token = "#"
+indent = { tab-width = 2, unit = "  " }
+formatter = { command = "mylang-formatter" , args = ["--stdin"] }
+language-servers = [ "mylang-lsp" ]
+```
+
+These configuration keys are available:
+
+| Key                   | Description                                                   |
+| ----                  | -----------                                                   |
+| `name`                | The name of the language                                      |
+| `language-id`         | The language-id for language servers, checkout the table at [TextDocumentItem](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocumentItem) for the right id |
+| `scope`               | A string like `source.js` that identifies the language. Currently, we strive to match the scope names used by popular TextMate grammars and by the Linguist library. Usually `source.<name>` or `text.<name>` in case of markup languages |
+| `injection-regex`     | regex pattern that will be tested against a language name in order to determine whether this language should be used for a potential [language injection][treesitter-language-injection] site. |
+| `file-types`          | The filetypes of the language, for example `["yml", "yaml"]`. See the file-type detection section below. |
+| `shebangs`            | The interpreters from the shebang line, for example `["sh", "bash"]` |
+| `roots`               | A set of marker files to look for when trying to find the workspace root. For example `Cargo.lock`, `yarn.lock` |
+| `auto-format`         | Whether to autoformat this language when saving               |
+| `diagnostic-severity` | Minimal severity of diagnostic for it to be displayed. (Allowed values: `Error`, `Warning`, `Info`, `Hint`) |
+| `comment-token`       | The token to use as a comment-token                           |
+| `indent`              | The indent to use. Has sub keys `unit` (the text inserted into the document when indenting; usually set to N spaces or `"\t"` for tabs) and `tab-width` (the number of spaces rendered for a tab) |
+| `language-servers`    | The Language Servers used for this language. See below for more information in the section [Configuring Language Servers for a language](#configuring-language-servers-for-a-language)   |
+| `grammar`             | The tree-sitter grammar to use (defaults to the value of `name`) |
+| `formatter`           | The formatter for the language, it will take precedence over the lsp when defined. The formatter must be able to take the original file as input from stdin and write the formatted file to stdout |
+| `soft-wrap` | [editor.softwrap](./configuration.md#editorsoft-wrap-section)
+| `text-width`          |  Maximum line length. Used for the `:reflow` command and soft-wrapping if `soft-wrap.wrap-at-text-width` is set, defaults to `editor.text-width`   |
+| `workspace-lsp-roots`     | Directories relative to the workspace root that are treated as LSP roots. Should only be set in `.helix/config.toml`. Overwrites the setting of the same name in `config.toml` if set. |
+| `persistent-diagnostic-sources` | An array of LSP diagnostic sources assumed unchanged when the language server resends the same set of diagnostics. Helix can track the position for these diagnostics internally instead. Useful for diagnostics that are recomputed on save.
+
+### File-type detection and the `file-types` key
+
+Helix determines which language configuration to use based on the `file-types` key
+from the above section. `file-types` is a list of strings or tables, for
+example:
+
+```toml
+file-types = ["Makefile", "toml", { suffix = ".git/config" }]
+```
+
+When determining a language configuration to use, Helix searches the file-types
+with the following priorities:
+
+1. Exact match: if the filename of a file is an exact match of a string in a
+   `file-types` list, that language wins. In the example above, `"Makefile"`
+   will match against `Makefile` files.
+2. Extension: if there are no exact matches, any `file-types` string that
+   matches the file extension of a given file wins. In the example above, the
+   `"toml"` matches files like `Cargo.toml` or `languages.toml`.
+3. Suffix: if there are still no matches, any values in `suffix` tables
+   are checked against the full path of the given file. In the example above,
+   the `{ suffix = ".git/config" }` would match against any `config` files
+   in `.git` directories. Note: `/` is used as the directory separator but is
+   replaced at runtime with the appropriate path separator for the operating
+   system, so this rule would match against `.git\config` files on Windows.
+
+## Language Server configuration
+
+Language servers are configured separately in the table `language-server` in the same file as the languages `languages.toml`
+
+For example:
+
+```toml
+[language-server.mylang-lsp]
+command = "mylang-lsp"
+args = ["--stdio"]
+config = { provideFormatter = true }
+environment = { "ENV1" = "value1", "ENV2" = "value2" }
+
+[language-server.efm-lsp-prettier]
+command = "efm-langserver"
+
+[language-server.efm-lsp-prettier.config]
+documentFormatting = true
+languages = { typescript = [ { formatCommand ="prettier --stdin-filepath ${INPUT}", formatStdin = true } ] }
+```
+
+These are the available options for a language server.
+
+| Key                   | Description                                                                              |
+| ----                  | -----------                                                                              |
+| `command`             | The name or path of the language server binary to execute. Binaries must be in `$PATH`   |
+| `args`                | A list of arguments to pass to the language server binary                                |
+| `config`              | LSP initialization options                               |
+| `timeout`             | The maximum time a request to the language server may take, in seconds. Defaults to `20` |
+| `environment`         | Any environment variables that will be used when starting the language server `{ "KEY1" = "Value1", "KEY2" = "Value2" }` |
+
+A `format` sub-table within `config` can be used to pass extra formatting options to
+[Document Formatting Requests](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_formatting).
+For example, with typescript:
+
+```toml
+[language-server.typescript-language-server]
+# pass format options according to https://github.com/typescript-language-server/typescript-language-server#workspacedidchangeconfiguration omitting the "[language].format." prefix.
+config = { format = { "semicolons" = "insert", "insertSpaceBeforeFunctionParenthesis" = true } }
+```
+
+### Configuring Language Servers for a language
+
+The `language-servers` attribute in a language tells helix which language servers are used for this language.
+
+They have to be defined in the `[language-server]` table as described in the previous section.
+
+Different languages can use the same language server instance, e.g. `typescript-language-server` is used for javascript, jsx, tsx and typescript by default.
+
+In case multiple language servers are specified in the `language-servers` attribute of a `language`,
+it's often useful to only enable/disable certain language-server features for these language servers.
+
+As an example, `efm-lsp-prettier` of the previous example is used only with a formatting command `prettier`,
+so everything else should be handled by the `typescript-language-server` (which is configured by default).
+The language configuration for typescript could look like this:
+
+```toml
+[[language]]
+name = "typescript"
+language-servers = [ { name = "efm-lsp-prettier", only-features = [ "format" ] }, "typescript-language-server" ]
+```
+
+or equivalent:
+
+```toml
+[[language]]
+name = "typescript"
+language-servers = [ { name = "typescript-language-server", except-features = [ "format" ] }, "efm-lsp-prettier" ]
+```
+
+Each requested LSP feature is prioritized in the order of the `language-servers` array.
+For example, the first `goto-definition` supported language server (in this case `typescript-language-server`) will be taken for the relevant LSP request (command `goto_definition`).
+The features `diagnostics`, `code-action`, `completion`, `document-symbols` and `workspace-symbols` are an exception to that rule, as they are working for all language servers at the same time and are merged together, if enabled for the language.
+If no `except-features` or `only-features` is given, all features for the language server are enabled.
+If a language server itself doesn't support a feature, the next language server array entry will be tried (and so on).
+
+The list of supported features is:
+
+- `format`
+- `goto-definition`
+- `goto-declaration`
+- `goto-type-definition`
+- `goto-reference`
+- `goto-implementation`
+- `signature-help`
+- `hover`
+- `document-highlight`
+- `completion`
+- `code-action`
+- `workspace-command`
+- `document-symbols`
+- `workspace-symbols`
+- `diagnostics`
+- `rename-symbol`
+- `inlay-hints`
+
+## Tree-sitter grammar configuration
+
+The source for a language's tree-sitter grammar is specified in a `[[grammar]]`
+section in `languages.toml`. For example:
+
+```toml
+[[grammar]]
+name = "mylang"
+source = { git = "https://github.com/example/mylang", rev = "a250c4582510ff34767ec3b7dcdd3c24e8c8aa68" }
+```
+
+Grammar configuration takes these keys:
+
+| Key      | Description                                                              |
+| ---      | -----------                                                              |
+| `name`   | The name of the tree-sitter grammar                                      |
+| `source` | The method of fetching the grammar - a table with a schema defined below |
+
+Where `source` is a table with either these keys when using a grammar from a
+git repository:
+
+| Key    | Description                                               |
+| ---    | -----------                                               |
+| `git`  | A git remote URL from which the grammar should be cloned  |
+| `rev`  | The revision (commit hash or tag) which should be fetched |
+| `subpath` | A path within the grammar directory which should be built. Some grammar repositories host multiple grammars (for example `tree-sitter-typescript` and `tree-sitter-ocaml`) in subdirectories. This key is used to point `hx --grammar build` to the correct path for compilation. When omitted, the root of repository is used |
+
+### Choosing grammars
+
+You may use a top-level `use-grammars` key to control which grammars are
+fetched and built when using `hx --grammar fetch` and `hx --grammar build`.
+
+```toml
+# Note: this key must come **before** the [[language]] and [[grammar]] sections
+use-grammars = { only = [ "rust", "c", "cpp" ] }
+# or
+use-grammars = { except = [ "yaml", "json" ] }
+```
+
+When omitted, all grammars are fetched and built.
+
+[treesitter-language-injection]: https://tree-sitter.github.io/tree-sitter/syntax-highlighting#language-injection

book/src/remapping.md

@@ -0,0 +1,79 @@
+# Key remapping
+
+Helix currently supports one-way key remapping through a simple TOML configuration
+file. (More powerful solutions such as rebinding via commands will be
+available in the future).
+
+To remap keys, create a `config.toml` file in your `helix` configuration
+directory (default `~/.config/helix` on Linux systems) with a structure like
+this:
+
+```toml
+# At most one section each of 'keys.normal', 'keys.insert' and 'keys.select'
+[keys.normal]
+C-s = ":w" # Maps Ctrl-s to the typable command :w which is an alias for :write (save file)
+C-o = ":open ~/.config/helix/config.toml" # Maps Ctrl-o to opening of the helix config file
+a = "move_char_left" # Maps the 'a' key to the move_char_left command
+w = "move_line_up" # Maps the 'w' key move_line_up
+"C-S-esc" = "extend_line" # Maps Ctrl-Shift-Escape to extend_line
+g = { a = "code_action" } # Maps `ga` to show possible code actions
+"ret" = ["open_below", "normal_mode"] # Maps the enter key to open_below then re-enter normal mode
+
+[keys.insert]
+"A-x" = "normal_mode"     # Maps Alt-X to enter normal mode
+j = { k = "normal_mode" } # Maps `jk` to exit insert mode
+```
+
+## Minor modes
+
+Minor modes are accessed by pressing a key (usually from normal mode), giving access to dedicated bindings. Bindings
+can be modified or added by nesting definitions.
+
+```toml
+[keys.insert.j]
+k = "normal_mode" # Maps `jk` to exit insert mode
+
+[keys.normal.g]
+a = "code_action" # Maps `ga` to show possible code actions
+
+# invert `j` and `k` in view mode
+[keys.normal.z]
+j = "scroll_up"
+k = "scroll_down"
+
+# create a new minor mode bound to `+`
+[keys.normal."+"]
+m = ":run-shell-command make"
+c = ":run-shell-command cargo build"
+t = ":run-shell-command cargo test"
+```
+
+## Special keys and modifiers
+
+Ctrl, Shift and Alt modifiers are encoded respectively with the prefixes
+`C-`, `S-` and `A-`. Special keys are encoded as follows:
+
+| Key name     | Representation |
+| ---          | ---            |
+| Backspace    | `"backspace"`  |
+| Space        | `"space"`      |
+| Return/Enter | `"ret"`        |
+| \-           | `"minus"`      |
+| Left         | `"left"`       |
+| Right        | `"right"`      |
+| Up           | `"up"`         |
+| Down         | `"down"`       |
+| Home         | `"home"`       |
+| End          | `"end"`        |
+| Page Up      | `"pageup"`     |
+| Page Down    | `"pagedown"`   |
+| Tab          | `"tab"`        |
+| Delete       | `"del"`        |
+| Insert       | `"ins"`        |
+| Null         | `"null"`       |
+| Escape       | `"esc"`        |
+
+Keys can be disabled by binding them to the `no_op` command.
+
+A list of commands is available in the [Keymap](https://docs.helix-editor.com/keymap.html) documentation
+ and in the source code at [`helix-term/src/commands.rs`](https://github.com/helix-editor/helix/blob/master/helix-term/src/commands.rs) at the invocation of `static_commands!` macro and the `TypableCommandList`.

book/src/themes.md

@@ -0,0 +1,337 @@
+# Themes
+
+To use a theme add `theme = "<name>"` to the top of your [`config.toml`](./configuration.md) file, or select it during runtime using `:theme <name>`.
+
+## Creating a theme
+
+Create a file with the name of your theme as the file name (i.e `mytheme.toml`) and place it in your `themes` directory (i.e `~/.config/helix/themes` or `%AppData%\helix\themes` on Windows). The directory might have to be created beforehand.
+
+> 💡 The names "default" and "base16_default" are reserved for built-in themes
+> and cannot be overridden by user-defined themes.
+
+### Overview
+
+Each line in the theme file is specified as below:
+
+```toml
+key = { fg = "#ffffff", bg = "#000000", underline = { color = "#ff0000", style = "curl"}, modifiers = ["bold", "italic"] }
+```
+
+Where `key` represents what you want to style, `fg` specifies the foreground color, `bg` the background color, `underline` the underline `style`/`color`, and `modifiers` is a list of style modifiers. `bg`, `underline` and `modifiers` can be omitted to defer to the defaults.
+
+To specify only the foreground color:
+
+```toml
+key = "#ffffff"
+```
+
+If the key contains a dot `'.'`, it must be quoted to prevent it being parsed as a [dotted key](https://toml.io/en/v1.0.0#keys).
+
+```toml
+"key.key" = "#ffffff"
+```
+
+For inspiration, you can find the default `theme.toml`
+[here](https://github.com/helix-editor/helix/blob/master/theme.toml) and
+user-submitted themes
+[here](https://github.com/helix-editor/helix/blob/master/runtime/themes).
+
+### Using the linter
+
+Use the supplied linting tool to check for errors and missing scopes:
+
+```sh
+cargo xtask themelint onedark # replace onedark with <name>
+```
+
+## The details of theme creation
+
+### Color palettes
+
+It's recommended to define a palette of named colors, and refer to them in the
+configuration values in your theme. To do this, add a table called
+`palette` to your theme file:
+
+```toml
+"ui.background" = "white"
+"ui.text" = "black"
+
+[palette]
+white = "#ffffff"
+black = "#000000"
+```
+
+Keep in mind that the `[palette]` table includes all keys after its header,
+so it should be defined after the normal theme options.
+
+The default palette uses the terminal's default 16 colors, and the colors names
+are listed below. The `[palette]` section in the config file takes precedence
+over it and is merged into the default palette.
+
+| Color Name      |
+| ---             |
+| `default`       |
+| `black`         |
+| `red`           |
+| `green`         |
+| `yellow`        |
+| `blue`          |
+| `magenta`       |
+| `cyan`          |
+| `gray`          |
+| `light-red`     |
+| `light-green`   |
+| `light-yellow`  |
+| `light-blue`    |
+| `light-magenta` |
+| `light-cyan`    |
+| `light-gray`    |
+| `white`         |
+
+### Modifiers
+
+The following values may be used as modifier, provided they are supported by
+your terminal emulator.
+
+| Modifier             |
+| ---                  |
+| `bold`               |
+| `dim`                |
+| `italic`             |
+| `underlined`         |
+| `slow_blink`         |
+| `rapid_blink`        |
+| `reversed`           |
+| `hidden`             |
+| `crossed_out`        |
+
+> 💡 The `underlined` modifier is deprecated and only available for backwards compatibility.
+> Its behavior is equivalent to setting `underline.style="line"`.
+
+### Underline style
+
+One of the following values may be used as a value for `underline.style`, providing it is
+supported by your terminal emulator.
+
+| Modifier       |
+| ---            |
+| `line`         |
+| `curl`         |
+| `dashed`       |
+| `dotted`       |
+| `double_line`  |
+
+
+### Inheritance
+
+Extend other themes by setting the `inherits` property to an existing theme.
+
+```toml
+inherits = "boo_berry"
+
+# Override the theming for "keyword"s:
+"keyword" = { fg = "gold" }
+
+# Override colors in the palette:
+[palette]
+berry = "#2A2A4D"
+```
+
+### Scopes
+
+The following is a list of scopes available to use for styling:
+
+#### Syntax highlighting
+
+These keys match [tree-sitter scopes](https://tree-sitter.github.io/tree-sitter/syntax-highlighting#theme).
+
+When determining styling for a highlight, the longest matching theme key will be used. For example, if the highlight is `function.builtin.static`, the key `function.builtin` will be used instead of `function`.
+
+We use a similar set of scopes as
+[Sublime Text](https://www.sublimetext.com/docs/scope_naming.html). See also
+[TextMate](https://macromates.com/manual/en/language_grammars) scopes.
+
+- `attribute` - Class attributes, HTML tag attributes
+
+- `type` - Types
+  - `builtin` - Primitive types provided by the language (`int`, `usize`)
+  - `parameter` - Generic type parameters (`T`)
+  - `enum`
+    - `variant`
+- `constructor`
+
+- `constant` (TODO: constant.other.placeholder for `%v`)
+  - `builtin` Special constants provided by the language (`true`, `false`, `nil` etc)
+    - `boolean`
+  - `character`
+    - `escape`
+  - `numeric` (numbers)
+    - `integer`
+    - `float`
+
+- `string` (TODO: string.quoted.{single, double}, string.raw/.unquoted)?
+  - `regexp` - Regular expressions
+  - `special`
+    - `path`
+    - `url`
+    - `symbol` - Erlang/Elixir atoms, Ruby symbols, Clojure keywords
+
+- `comment` - Code comments
+  - `line` - Single line comments (`//`)
+  - `block` - Block comments (e.g. (`/* */`)
+    - `documentation` - Documentation comments (e.g. `///` in Rust)
+
+- `variable` - Variables
+  - `builtin` - Reserved language variables (`self`, `this`, `super`, etc.)
+  - `parameter` - Function parameters
+  - `other`
+    - `member` - Fields of composite data types (e.g. structs, unions)
+
+- `label`
+
+- `punctuation`
+  - `delimiter` - Commas, colons
+  - `bracket` - Parentheses, angle brackets, etc.
+  - `special` - String interpolation brackets.
+
+- `keyword`
+  - `control`
+    - `conditional` - `if`, `else`
+    - `repeat` - `for`, `while`, `loop`
+    - `import` - `import`, `export`
+    - `return`
+    - `exception`
+  - `operator` - `or`, `in`
+  - `directive` - Preprocessor directives (`#if` in C)
+  - `function` - `fn`, `func`
+  - `storage` - Keywords describing how things are stored
+    - `type` - The type of something, `class`, `function`, `var`, `let`, etc.
+    - `modifier` - Storage modifiers like `static`, `mut`, `const`, `ref`, etc.
+
+- `operator` - `||`, `+=`, `>`
+
+- `function`
+  - `builtin`
+  - `method`
+  - `macro`
+  - `special` (preprocessor in C)
+
+- `tag` - Tags (e.g. `<body>` in HTML)
+  - `builtin`
+
+- `namespace`
+
+- `special`
+
+- `markup`
+  - `heading`
+    - `marker`
+    - `1`, `2`, `3`, `4`, `5`, `6` - heading text for h1 through h6
+  - `list`
+    - `unnumbered`
+    - `numbered`
+    - `checked`
+    - `unchecked`
+  - `bold`
+  - `italic`
+  - `strikethrough`
+  - `link`
+    - `url` - URLs pointed to by links
+    - `label` - non-URL link references
+    - `text` - URL and image descriptions in links
+  - `quote`
+  - `raw`
+    - `inline`
+    - `block`
+
+- `diff` - version control changes
+  - `plus` - additions
+    - `gutter` - gutter indicator
+  - `minus` - deletions
+    - `gutter` - gutter indicator
+  - `delta` - modifications
+    - `moved` - renamed or moved files/changes
+    - `gutter` - gutter indicator
+
+#### Interface
+
+These scopes are used for theming the editor interface:
+
+- `markup`
+  - `normal`
+    - `completion` - for completion doc popup UI
+    - `hover` - for hover popup UI
+  - `heading`
+    - `completion` - for completion doc popup UI
+    - `hover` - for hover popup UI
+  - `raw`
+    - `inline`
+      - `completion` - for completion doc popup UI
+      - `hover` - for hover popup UI
+
+
+| Key                               | Notes                                                                                          |
+| ---                               | ---                                                                                            |
+| `ui.background`                   |                                                                                                |
+| `ui.background.separator`         | Picker separator below input line                                                              |
+| `ui.cursor`                       |                                                                                                |
+| `ui.cursor.normal`                |                                                                                                |
+| `ui.cursor.insert`                |                                                                                                |
+| `ui.cursor.select`                |                                                                                                |
+| `ui.cursor.match`                 | Matching bracket etc.                                                                          |
+| `ui.cursor.primary`               | Cursor with primary selection                                                                  |
+| `ui.cursor.primary.normal`        |                                                                                                |
+| `ui.cursor.primary.insert`        |                                                                                                |
+| `ui.cursor.primary.select`        |                                                                                                |
+| `ui.debug.breakpoint`             | Breakpoint indicator, found in the gutter                                                      |
+| `ui.debug.active`                 | Indicator for the line at which debugging execution is paused at, found in the gutter          |
+| `ui.gutter`                       | Gutter                                                                                         |
+| `ui.gutter.selected`              | Gutter for the line the cursor is on                                                           |
+| `ui.highlight.frameline`          | Line at which debugging execution is paused at                                                 |
+| `ui.linenr`                       | Line numbers                                                                                   |
+| `ui.linenr.selected`              | Line number for the line the cursor is on                                                      |
+| `ui.statusline`                   | Statusline                                                                                     |
+| `ui.statusline.inactive`          | Statusline (unfocused document)                                                                |
+| `ui.statusline.normal`            | Statusline mode during normal mode ([only if `editor.color-modes` is enabled][editor-section]) |
+| `ui.statusline.insert`            | Statusline mode during insert mode ([only if `editor.color-modes` is enabled][editor-section]) |
+| `ui.statusline.select`            | Statusline mode during select mode ([only if `editor.color-modes` is enabled][editor-section]) |
+| `ui.statusline.separator`         | Separator character in statusline                                                              |
+| `ui.bufferline`                   | Style for the buffer line                                                                      |
+| `ui.bufferline.active`            | Style for the active buffer in buffer line                                                        |
+| `ui.bufferline.background`        | Style for bufferline background                                                                |
+| `ui.popup`                        | Documentation popups (e.g. Space + k)                                                          |
+| `ui.popup.info`                   | Prompt for multiple key options                                                                |
+| `ui.window`                       | Borderlines separating splits                                                                  |
+| `ui.help`                         | Description box for commands                                                                   |
+| `ui.text`                         | Default text style, command prompts, popup text, etc.                                          |
+| `ui.text.focus`                   | The currently selected line in the picker                                                      |
+| `ui.text.inactive`                | Same as `ui.text` but when the text is inactive (e.g. suggestions)                             |
+| `ui.text.info`                    | The key: command text in `ui.popup.info` boxes                                                 |
+| `ui.virtual.ruler`                | Ruler columns (see the [`editor.rulers` config][editor-section])                               |
+| `ui.virtual.whitespace`           | Visible whitespace characters                                                                  |
+| `ui.virtual.indent-guide`         | Vertical indent width guides                                                                   |
+| `ui.virtual.inlay-hint`           | Default style for inlay hints of all kinds                                                     |
+| `ui.virtual.inlay-hint.parameter` | Style for inlay hints of kind `parameter` (LSPs are not required to set a kind)                |
+| `ui.virtual.inlay-hint.type`      | Style for inlay hints of kind `type` (LSPs are not required to set a kind)                     |
+| `ui.virtual.wrap`                 | Soft-wrap indicator (see the [`editor.soft-wrap` config][editor-section])                      |
+| `ui.menu`                         | Code and command completion menus                                                              |
+| `ui.menu.selected`                | Selected autocomplete item                                                                     |
+| `ui.menu.scroll`                  | `fg` sets thumb color, `bg` sets track color of scrollbar                                      |
+| `ui.selection`                    | For selections in the editing area                                                             |
+| `ui.selection.primary`            |                                                                                                |
+| `ui.highlight`                    | Highlighted lines in the picker preview                                                        |
+| `ui.cursorline.primary`           | The line of the primary cursor ([if cursorline is enabled][editor-section])                    |
+| `ui.cursorline.secondary`         | The lines of any other cursors ([if cursorline is enabled][editor-section])                    |
+| `ui.cursorcolumn.primary`         | The column of the primary cursor ([if cursorcolumn is enabled][editor-section])                |
+| `ui.cursorcolumn.secondary`       | The columns of any other cursors ([if cursorcolumn is enabled][editor-section])                |
+| `warning`                         | Diagnostics warning (gutter)                                                                   |
+| `error`                           | Diagnostics error (gutter)                                                                     |
+| `info`                            | Diagnostics info (gutter)                                                                      |
+| `hint`                            | Diagnostics hint (gutter)                                                                      |
+| `diagnostic`                      | Diagnostics fallback style (editing area)                                                      |
+| `diagnostic.hint`                 | Diagnostics hint (editing area)                                                                |
+| `diagnostic.info`                 | Diagnostics info (editing area)                                                                |
+| `diagnostic.warning`              | Diagnostics warning (editing area)                                                             |
+| `diagnostic.error`                | Diagnostics error (editing area)                                                               |
+
+[editor-section]: ./configuration.md#editor-section

book/src/title-page.md

@@ -0,0 +1,17 @@
+# Helix
+
+Docs for bleeding edge master can be found at
+[https://docs.helix-editor.com/master](https://docs.helix-editor.com/master).
+
+See the [usage] section for a quick overview of the editor, [keymap]
+section for all available keybindings and the [configuration] section
+for defining custom keybindings, setting themes, etc.
+For everything else (e.g., how to install supported language servers), see the [Helix Wiki].
+
+Refer the [FAQ] for common questions.
+
+[FAQ]: https://github.com/helix-editor/helix/wiki/FAQ
+[usage]: ./usage.md
+[keymap]: ./keymap.md
+[configuration]: ./configuration.md
+[Helix Wiki]: https://github.com/helix-editor/helix/wiki

book/src/usage.md

@@ -1 +1,208 @@
-# Usage
+# Using Helix
+
+<!--toc:start-->
+- [Registers](#registers)
+  - [User-defined registers](#user-defined-registers)
+  - [Special registers](#special-registers)
+- [Surround](#surround)
+- [Selecting and manipulating text with textobjects](#selecting-and-manipulating-text-with-textobjects)
+- [Navigating using tree-sitter textobjects](#navigating-using-tree-sitter-textobjects)
+- [Moving the selection with syntax-aware motions](#moving-the-selection-with-syntax-aware-motions)
+<!--toc:end-->
+
+For a full interactive introduction to Helix, refer to the
+[tutor](https://github.com/helix-editor/helix/blob/master/runtime/tutor) which
+can be accessed via the command `hx --tutor` or `:tutor`.
+
+> 💡 Currently, not all functionality is fully documented, please refer to the
+> [key mappings](./keymap.md) list.
+
+## Registers
+
+In Helix, registers are storage locations for text and other data, such as the
+result of a search. Registers can be used to cut, copy, and paste text, similar
+to the clipboard in other text editors. Usage is similar to Vim, with `"` being
+used to select a register.
+
+### User-defined registers
+
+Helix allows you to create your own named registers for storing text, for
+example:
+
+- `"ay` - Yank the current selection to register `a`.
+- `"op` - Paste the text in register `o` after the selection.
+
+If a register is selected before invoking a change or delete command, the selection will be stored in the register and the action will be carried out:
+
+- `"hc` - Store the selection in register `h` and then change it (delete and enter insert mode).
+- `"md` - Store the selection in register `m` and delete it.
+
+### Default registers
+
+Commands that use registers, like yank (`y`), use a default register if none is specified.
+These registers are used as defaults:
+
+| Register character | Contains              |
+| ---                | ---                   |
+| `/`                | Last search           |
+| `:`                | Last executed command |
+| `"`                | Last yanked text      |
+| `@`                | Last recorded macro   |
+
+### Special registers
+
+Some registers have special behavior when read from and written to.
+
+| Register character | When read              | When written             |
+| ---                | ---                    | ---                      |
+| `_`                | No values are returned | All values are discarded |
+| `#`                | Selection indices (first selection is `1`, second is `2`, etc.) | This register is not writable |
+| `.`                | Contents of the current selections | This register is not writable |
+| `%`                | Name of the current file | This register is not writable |
+| `+`                | Reads from the system clipboard | Joins and yanks to the system clipboard |
+| `*`                | Reads from the primary clipboard | Joins and yanks to the primary clipboard |
+
+When yanking multiple selections to the clipboard registers, the selections
+are joined with newlines. Pasting from these registers will paste multiple
+selections if the clipboard was last yanked to by the Helix session. Otherwise
+the clipboard contents are pasted as one selection.
+
+## Surround
+
+Helix includes built-in functionality similar to [vim-surround](https://github.com/tpope/vim-surround).
+The keymappings have been inspired from [vim-sandwich](https://github.com/machakann/vim-sandwich):
+
+![Surround demo](https://user-images.githubusercontent.com/23398472/122865801-97073180-d344-11eb-8142-8f43809982c6.gif)
+
+| Key Sequence                      | Action                                  |
+| --------------------------------- | --------------------------------------- |
+| `ms<char>` (after selecting text) | Add surround characters to selection    |
+| `mr<char_to_replace><new_char>`   | Replace the closest surround characters |
+| `md<char_to_delete>`              | Delete the closest surround characters  |
+
+You can use counts to act on outer pairs.
+
+Surround can also act on multiple selections. For example, to change every occurrence of `(use)` to `[use]`:
+
+1. `%` to select the whole file
+2. `s` to split the selections on a search term
+3. Input `use` and hit Enter
+4. `mr([` to replace the parentheses with square brackets
+
+Multiple characters are currently not supported, but planned for future release.
+
+## Selecting and manipulating text with textobjects
+
+In Helix, textobjects are a way to select, manipulate and operate on a piece of
+text in a structured way. They allow you to refer to blocks of text based on
+their structure or purpose, such as a word, sentence, paragraph, or even a
+function or block of code.
+
+![Textobject demo](https://user-images.githubusercontent.com/23398472/124231131-81a4bb00-db2d-11eb-9d10-8e577ca7b177.gif)
+![Textobject tree-sitter demo](https://user-images.githubusercontent.com/23398472/132537398-2a2e0a54-582b-44ab-a77f-eb818942203d.gif)
+
+- `ma` - Select around the object (`va` in Vim, `<alt-a>` in Kakoune)
+- `mi` - Select inside the object (`vi` in Vim, `<alt-i>` in Kakoune)
+
+| Key after `mi` or `ma` | Textobject selected      |
+| ---                    | ---                      |
+| `w`                    | Word                     |
+| `W`                    | WORD                     |
+| `p`                    | Paragraph                |
+| `(`, `[`, `'`, etc.    | Specified surround pairs |
+| `m`                    | The closest surround pair    |
+| `f`                    | Function                 |
+| `t`                    | Type (or Class)          |
+| `a`                    | Argument/parameter       |
+| `c`                    | Comment                  |
+| `T`                    | Test                     |
+| `g`                    | Change                   |
+
+> 💡 `f`, `t`, etc. need a tree-sitter grammar active for the current
+document and a special tree-sitter query file to work properly. [Only
+some grammars][lang-support] currently have the query file implemented.
+Contributions are welcome!
+
+## Navigating using tree-sitter textobjects
+
+Navigating between functions, classes, parameters, and other elements is
+possible using tree-sitter and textobject queries. For
+example to move to the next function use `]f`, to move to previous
+type use `[t`, and so on.
+
+![Tree-sitter-nav-demo][tree-sitter-nav-demo]
+
+For the full reference see the [unimpaired][unimpaired-keybinds] section of the key bind
+documentation.
+
+> 💡 This feature relies on tree-sitter textobjects
+> and requires the corresponding query file to work properly.
+
+## Moving the selection with syntax-aware motions
+
+`Alt-p`, `Alt-o`, `Alt-i`, and `Alt-n` (or `Alt` and arrow keys) allow you to move the 
+selection according to its location in the syntax tree. For example, many languages have the
+following syntax for function calls:
+
+```js
+func(arg1, arg2, arg3);
+```
+
+A function call might be parsed by tree-sitter into a tree like the following.
+
+```tsq
+(call
+  function: (identifier) ; func
+  arguments:
+    (arguments           ; (arg1, arg2, arg3)
+      (identifier)       ; arg1
+      (identifier)       ; arg2
+      (identifier)))     ; arg3
+```
+
+Use `:tree-sitter-subtree` to view the syntax tree of the primary selection. In
+a more intuitive tree format:
+
+```
+            ┌────┐
+            │call│
+      ┌─────┴────┴─────┐
+      │                │
+┌─────▼────┐      ┌────▼────┐
+│identifier│      │arguments│
+│  "func"  │ ┌────┴───┬─────┴───┐
+└──────────┘ │        │         │
+             │        │         │
+   ┌─────────▼┐  ┌────▼─────┐  ┌▼─────────┐
+   │identifier│  │identifier│  │identifier│
+   │  "arg1"  │  │  "arg2"  │  │  "arg3"  │
+   └──────────┘  └──────────┘  └──────────┘
+```
+
+If you have a selection that wraps `arg1` (see the tree above), and you use
+`Alt-n`, it will select the next sibling in the syntax tree: `arg2`.
+
+```js
+// before
+func([arg1], arg2, arg3)
+// after
+func(arg1, [arg2], arg3);
+```
+
+Similarly, `Alt-o` will expand the selection to the parent node, in this case, the
+arguments node.
+
+```js
+func[(arg1, arg2, arg3)];
+```
+
+There is also some nuanced behavior that prevents you from getting stuck on a
+node with no sibling. When using `Alt-p` with a selection on `arg1`, the previous
+child node will be selected. In the event that `arg1` does not have a previous
+sibling, the selection will move up the syntax tree and select the previous
+element. As a result, using `Alt-p` with a selection on `arg1` will move the
+selection to the "func" `identifier`.
+
+[lang-support]: ./lang-support.md
+[unimpaired-keybinds]: ./keymap.md#unimpaired
+[tree-sitter-nav-demo]: https://user-images.githubusercontent.com/23398472/152332550-7dfff043-36a2-4aec-b8f2-77c13eb56d6f.gif

book/theme/book.js

@@ -1,660 +0,0 @@
-"use strict";
-
-// Fix back button cache problem
-window.onunload = function () { };
-
-// Global variable, shared between modules
-function playground_text(playground) {
-    let code_block = playground.querySelector("code");
-
-    if (window.ace && code_block.classList.contains("editable")) {
-        let editor = window.ace.edit(code_block);
-        return editor.getValue();
-    } else {
-        return code_block.textContent;
-    }
-}
-
-(function codeSnippets() {
-    function fetch_with_timeout(url, options, timeout = 6000) {
-        return Promise.race([
-            fetch(url, options),
-            new Promise((_, reject) => setTimeout(() => reject(new Error('timeout')), timeout))
-        ]);
-    }
-
-    var playgrounds = Array.from(document.querySelectorAll(".playground"));
-    if (playgrounds.length > 0) {
-        fetch_with_timeout("https://play.rust-lang.org/meta/crates", {
-            headers: {
-                'Content-Type': "application/json",
-            },
-            method: 'POST',
-            mode: 'cors',
-        })
-        .then(response => response.json())
-        .then(response => {
-            // get list of crates available in the rust playground
-            let playground_crates = response.crates.map(item => item["id"]);
-            playgrounds.forEach(block => handle_crate_list_update(block, playground_crates));
-        });
-    }
-
-    function handle_crate_list_update(playground_block, playground_crates) {
-        // update the play buttons after receiving the response
-        update_play_button(playground_block, playground_crates);
-
-        // and install on change listener to dynamically update ACE editors
-        if (window.ace) {
-            let code_block = playground_block.querySelector("code");
-            if (code_block.classList.contains("editable")) {
-                let editor = window.ace.edit(code_block);
-                editor.addEventListener("change", function (e) {
-                    update_play_button(playground_block, playground_crates);
-                });
-                // add Ctrl-Enter command to execute rust code
-                editor.commands.addCommand({
-                    name: "run",
-                    bindKey: {
-                        win: "Ctrl-Enter",
-                        mac: "Ctrl-Enter"
-                    },
-                    exec: _editor => run_rust_code(playground_block)
-                });
-            }
-        }
-    }
-
-    // updates the visibility of play button based on `no_run` class and
-    // used crates vs ones available on http://play.rust-lang.org
-    function update_play_button(pre_block, playground_crates) {
-        var play_button = pre_block.querySelector(".play-button");
-
-        // skip if code is `no_run`
-        if (pre_block.querySelector('code').classList.contains("no_run")) {
-            play_button.classList.add("hidden");
-            return;
-        }
-
-        // get list of `extern crate`'s from snippet
-        var txt = playground_text(pre_block);
-        var re = /extern\s+crate\s+([a-zA-Z_0-9]+)\s*;/g;
-        var snippet_crates = [];
-        var item;
-        while (item = re.exec(txt)) {
-            snippet_crates.push(item[1]);
-        }
-
-        // check if all used crates are available on play.rust-lang.org
-        var all_available = snippet_crates.every(function (elem) {
-            return playground_crates.indexOf(elem) > -1;
-        });
-
-        if (all_available) {
-            play_button.classList.remove("hidden");
-        } else {
-            play_button.classList.add("hidden");
-        }
-    }
-
-    function run_rust_code(code_block) {
-        var result_block = code_block.querySelector(".result");
-        if (!result_block) {
-            result_block = document.createElement('code');
-            result_block.className = 'result hljs language-bash';
-
-            code_block.append(result_block);
-        }
-
-        let text = playground_text(code_block);
-        let classes = code_block.querySelector('code').classList;
-        let has_2018 = classes.contains("edition2018");
-        let edition = has_2018 ? "2018" : "2015";
-
-        var params = {
-            version: "stable",
-            optimize: "0",
-            code: text,
-            edition: edition
-        };
-
-        if (text.indexOf("#![feature") !== -1) {
-            params.version = "nightly";
-        }
-
-        result_block.innerText = "Running...";
-
-        fetch_with_timeout("https://play.rust-lang.org/evaluate.json", {
-            headers: {
-                'Content-Type': "application/json",
-            },
-            method: 'POST',
-            mode: 'cors',
-            body: JSON.stringify(params)
-        })
-        .then(response => response.json())
-        .then(response => result_block.innerText = response.result)
-        .catch(error => result_block.innerText = "Playground Communication: " + error.message);
-    }
-
-    // Syntax highlighting Configuration
-    hljs.configure({
-        tabReplace: '    ', // 4 spaces
-        languages: [],      // Languages used for auto-detection
-    });
-
-    let code_nodes = Array
-        .from(document.querySelectorAll('code'))
-        // Don't highlight `inline code` blocks in headers.
-        .filter(function (node) {return !node.parentElement.classList.contains("header"); });
-
-    if (window.ace) {
-        // language-rust class needs to be removed for editable
-        // blocks or highlightjs will capture events
-        Array
-            .from(document.querySelectorAll('code.editable'))
-            .forEach(function (block) { block.classList.remove('language-rust'); });
-
-        Array
-            .from(document.querySelectorAll('code:not(.editable)'))
-            .forEach(function (block) { hljs.highlightBlock(block); });
-    } else {
-        code_nodes.forEach(function (block) { hljs.highlightBlock(block); });
-    }
-
-    // Adding the hljs class gives code blocks the color css
-    // even if highlighting doesn't apply
-    code_nodes.forEach(function (block) { block.classList.add('hljs'); });
-
-    Array.from(document.querySelectorAll("code.language-rust")).forEach(function (block) {
-
-        var lines = Array.from(block.querySelectorAll('.boring'));
-        // If no lines were hidden, return
-        if (!lines.length) { return; }
-        block.classList.add("hide-boring");
-
-        var buttons = document.createElement('div');
-        buttons.className = 'buttons';
-        buttons.innerHTML = "<button class=\"fa fa-eye\" title=\"Show hidden lines\" aria-label=\"Show hidden lines\"></button>";
-
-        // add expand button
-        var pre_block = block.parentNode;
-        pre_block.insertBefore(buttons, pre_block.firstChild);
-
-        pre_block.querySelector('.buttons').addEventListener('click', function (e) {
-            if (e.target.classList.contains('fa-eye')) {
-                e.target.classList.remove('fa-eye');
-                e.target.classList.add('fa-eye-slash');
-                e.target.title = 'Hide lines';
-                e.target.setAttribute('aria-label', e.target.title);
-
-                block.classList.remove('hide-boring');
-            } else if (e.target.classList.contains('fa-eye-slash')) {
-                e.target.classList.remove('fa-eye-slash');
-                e.target.classList.add('fa-eye');
-                e.target.title = 'Show hidden lines';
-                e.target.setAttribute('aria-label', e.target.title);
-
-                block.classList.add('hide-boring');
-            }
-        });
-    });
-
-    if (window.playground_copyable) {
-        Array.from(document.querySelectorAll('pre code')).forEach(function (block) {
-            var pre_block = block.parentNode;
-            if (!pre_block.classList.contains('playground')) {
-                var buttons = pre_block.querySelector(".buttons");
-                if (!buttons) {
-                    buttons = document.createElement('div');
-                    buttons.className = 'buttons';
-                    pre_block.insertBefore(buttons, pre_block.firstChild);
-                }
-
-                var clipButton = document.createElement('button');
-                clipButton.className = 'fa fa-copy clip-button';
-                clipButton.title = 'Copy to clipboard';
-                clipButton.setAttribute('aria-label', clipButton.title);
-                clipButton.innerHTML = '<i class=\"tooltiptext\"></i>';
-
-                buttons.insertBefore(clipButton, buttons.firstChild);
-            }
-        });
-    }
-
-    // Process playground code blocks
-    Array.from(document.querySelectorAll(".playground")).forEach(function (pre_block) {
-        // Add play button
-        var buttons = pre_block.querySelector(".buttons");
-        if (!buttons) {
-            buttons = document.createElement('div');
-            buttons.className = 'buttons';
-            pre_block.insertBefore(buttons, pre_block.firstChild);
-        }
-
-        var runCodeButton = document.createElement('button');
-        runCodeButton.className = 'fa fa-play play-button';
-        runCodeButton.hidden = true;
-        runCodeButton.title = 'Run this code';
-        runCodeButton.setAttribute('aria-label', runCodeButton.title);
-
-        buttons.insertBefore(runCodeButton, buttons.firstChild);
-        runCodeButton.addEventListener('click', function (e) {
-            run_rust_code(pre_block);
-        });
-
-        if (window.playground_copyable) {
-            var copyCodeClipboardButton = document.createElement('button');
-            copyCodeClipboardButton.className = 'fa fa-copy clip-button';
-            copyCodeClipboardButton.innerHTML = '<i class="tooltiptext"></i>';
-            copyCodeClipboardButton.title = 'Copy to clipboard';
-            copyCodeClipboardButton.setAttribute('aria-label', copyCodeClipboardButton.title);
-
-            buttons.insertBefore(copyCodeClipboardButton, buttons.firstChild);
-        }
-
-        let code_block = pre_block.querySelector("code");
-        if (window.ace && code_block.classList.contains("editable")) {
-            var undoChangesButton = document.createElement('button');
-            undoChangesButton.className = 'fa fa-history reset-button';
-            undoChangesButton.title = 'Undo changes';
-            undoChangesButton.setAttribute('aria-label', undoChangesButton.title);
-
-            buttons.insertBefore(undoChangesButton, buttons.firstChild);
-
-            undoChangesButton.addEventListener('click', function () {
-                let editor = window.ace.edit(code_block);
-                editor.setValue(editor.originalCode);
-                editor.clearSelection();
-            });
-        }
-    });
-})();
-
-(function themes() {
-    var html = document.querySelector('html');
-    var themeToggleButton = document.getElementById('theme-toggle');
-    var themePopup = document.getElementById('theme-list');
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-(function chapterNavigation() {
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book/theme/css/chrome.css

@@ -1,499 +0,0 @@
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-.chapter .section li.chapter-item {
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-    background-color: var(--sidebar-spacer);
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-    .chapter li a { padding: 5px 0; }
-    .spacer { margin: 10px 0; }
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-.section {
-    list-style: none outside none;
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-/* Theme Menu Popup */
-
-.theme-popup {
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-    left: 10px;
-    top: var(--menu-bar-height);
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-.theme-popup .theme:hover:first-child,
-.theme-popup .theme:hover:last-child {
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-    border-top-right-radius: inherit;
-}

book/theme/css/general.css

@@ -1,215 +0,0 @@
-/* Base styles and content styles */
-
-@import 'variables.css';
-
-:root {
-    /* Browser default font-size is 16px, this way 1 rem = 10px */
-    font-size: 62.5%;
-}
-
-/* TODO: replace with self hosted fonts */
-
-html {
-    font-family: "Inter", sans-serif;
-    color: var(--fg);
-    background-color: var(--bg);
-    text-size-adjust: none;
-}
-
-/* @supports (font-variation-settings: normal) { */
-/*   html { font-family: 'Inter var', sans-serif; } */
-/* } */
-
-body {
-    margin: 0;
-    font-size: 1.6rem;
-    overflow-x: hidden;
-}
-
-code {
-    font-family: "Source Code Pro", Consolas, "Ubuntu Mono", Menlo, "DejaVu Sans Mono", monospace, monospace !important;
-    font-size: 0.875em; /* please adjust the ace font size accordingly in editor.js */
-}
-
-/* Don't change font size in headers. */
-h1 code, h2 code, h3 code, h4 code, h5 code, h6 code {
-    font-size: unset;
-}
-
-.left { float: left; }
-.right { float: right; }
-.boring { opacity: 0.6; }
-.hide-boring .boring { display: none; }
-.hidden { display: none !important; }
-
-h2, h3 { margin-top: 2.5em; }
-h4, h5 { margin-top: 2em; }
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-.header + .header h3,
-.header + .header h4,
-.header + .header h5 {
-    margin-top: 1em;
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-h1:target::before,
-h2:target::before,
-h3:target::before,
-h4:target::before,
-h5:target::before,
-h6:target::before {
-    display: inline-block;
-    content: "»";
-    margin-left: -30px;
-    width: 30px;
-}
-
-/* This is broken on Safari as of version 14, but is fixed
-   in Safari Technology Preview 117 which I think will be Safari 14.2.
-   https://bugs.webkit.org/show_bug.cgi?id=218076
-*/
-:target {
-    scroll-margin-top: calc(var(--menu-bar-height) + 0.5em);
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-
-.page {
-    outline: 0;
-    padding: 0 var(--page-padding);
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-.page-wrapper {
-    box-sizing: border-box;
-}
-.js:not(.sidebar-resizing) .page-wrapper {
-    transition: margin-left 0.3s ease, transform 0.3s ease; /* Animation: slide away */
-}
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-.content {
-    overflow-y: auto;
-    padding: 0 15px;
-    padding-bottom: 50px;
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-.content main {
-    margin-left: auto;
-    margin-right: auto;
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-}
-
-
-/* 2 1.75 1.5 1.25 1 .875 */
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-.content h1 { font-size: 2em }
-.content h2 { font-size: 1.75em }
-.content h3 { font-size: 1.5em }
-.content h4 { font-size: 1.25em }
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-.content h6 { font-size: .875em }
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-.content h1, .content h2, .content h3, .content h4 {
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-.content ol { line-height: 1.45em; }
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-.content a:hover { text-decoration: underline; }
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-    margin: 0 auto;
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-table td {
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-}
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-}
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-}
-table tbody tr {
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-/* Alternate background colors for rows */
-table tbody tr:nth-child(2n) {
-    /* background: var(--table-alternate-bg); */
-}
-
-
-blockquote {
-    margin: 20px 0;
-    padding: 0 20px;
-    color: var(--fg);
-    background-color: var(--quote-bg);
-    border-top: .1em solid var(--quote-border);
-    border-bottom: .1em solid var(--quote-border);
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-
-
-:not(.footnote-definition) + .footnote-definition,
-.footnote-definition + :not(.footnote-definition) {
-    margin-top: 2em;
-}
-.footnote-definition {
-    font-size: 0.9em;
-    margin: 0.5em 0;
-}
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-    display: inline;
-}
-
-.tooltiptext {
-    position: absolute;
-    visibility: hidden;
-    color: #fff;
-    background-color: #333;
-    transform: translateX(-50%); /* Center by moving tooltip 50% of its width left */
-    left: -8px; /* Half of the width of the icon */
-    top: -35px;
-    font-size: 0.8em;
-    text-align: center;
-    border-radius: 6px;
-    padding: 5px 8px;
-    margin: 5px;
-    z-index: 1000;
-}
-.tooltipped .tooltiptext {
-    visibility: visible;
-}
-
-.chapter li.part-title {
-    color: var(--sidebar-fg);
-    margin: 5px 0px;
-    font-weight: bold;
-}

book/theme/css/print.css

@@ -1,54 +0,0 @@
-
-#sidebar,
-#menu-bar,
-.nav-chapters,
-.mobile-nav-chapters {
-    display: none;
-}
-
-#page-wrapper.page-wrapper {
-    transform: none;
-    margin-left: 0px;
-    overflow-y: initial;
-}
-
-#content {
-    max-width: none;
-    margin: 0;
-    padding: 0;
-}
-
-.page {
-    overflow-y: initial;
-}
-
-code {
-    background-color: #666666;
-    border-radius: 5px;
-
-    /* Force background to be printed in Chrome */
-    -webkit-print-color-adjust: exact;
-}
-
-pre > .buttons {
-    z-index: 2;
-}
-
-a, a:visited, a:active, a:hover {
-    color: #4183c4;
-    text-decoration: none;
-}
-
-h1, h2, h3, h4, h5, h6 {
-    page-break-inside: avoid;
-    page-break-after: avoid;
-}
-
-pre, code {
-    page-break-inside: avoid;
-    white-space: pre-wrap;
-}
-
-.fa {
-    display: none !important;
-}

book/theme/css/variables.css

@@ -1,337 +0,0 @@
-
-/* Globals */
-
-:root {
-    --sidebar-width: 300px;
-    --page-padding: 15px;
-    --content-max-width: 750px;
-    --menu-bar-height: 50px;
-}
-
-/* Themes */
-
-.ayu {
-    --bg: hsl(210, 25%, 8%);
-    --fg: #c5c5c5;
-
-    --sidebar-bg: #14191f;
-    --sidebar-fg: #c8c9db;
-    --sidebar-non-existant: #5c6773;
-    --sidebar-active: #ffb454;
-    --sidebar-spacer: #2d334f;
-
-    --scrollbar: var(--sidebar-fg);
-
-    --icons: #737480;
-    --icons-hover: #b7b9cc;
-
-    --links: #0096cf;
-
-    --inline-code-color: #ffb454;
-
-    --theme-popup-bg: #14191f;
-    --theme-popup-border: #5c6773;
-    --theme-hover: #191f26;
-
-    --quote-bg: hsl(226, 15%, 17%);
-    --quote-border: hsl(226, 15%, 22%);
-
-    --table-border-color: hsl(210, 25%, 13%);
-    --table-header-bg: hsl(210, 25%, 28%);
-    --table-alternate-bg: hsl(210, 25%, 11%);
-
-    --searchbar-border-color: #848484;
-    --searchbar-bg: #424242;
-    --searchbar-fg: #fff;
-    --searchbar-shadow-color: #d4c89f;
-    --searchresults-header-fg: #666;
-    --searchresults-border-color: #888;
-    --searchresults-li-bg: #252932;
-    --search-mark-bg: #e3b171;
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-    --searchbar-border-color: #aaa;
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book/theme/favicon.svg

@@ -1,22 +1 @@
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-  <style>
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-  c-1.3,0.9-2.4,1.8-3.2,2.8S52,6.5,51.2,8.1c-0.8,1.6-1.4,3-1.9,4.3s-1.1,2.7-1.8,4.2c-0.7,1.5-1.3,2.7-2,3.7c-0.5,0.6-1.2,1.5-2,2.5
-  s-1.6,2-2.2,2.8s-0.9,1.5-1.1,2.2c-0.2,0.7-0.1,1.8,0.2,3.2c0.3,1.4,0.4,2.4,0.4,3.1c-0.3,3-1.4,6.9-3.3,11.6
-  c-1.9,4.7-3.6,8.1-5.1,10.1c-0.3,0.4-1.2,1.3-2.6,2.7c-1.4,1.4-2.3,2.6-2.6,3.7c-0.3,0.4-0.3,1.5-0.1,3.4c0.3,1.8,0.4,3.1,0.3,3.8
-  c-0.3,2.7-1.3,6.3-3,10.8c-1.7,4.5-3.4,8.2-5,11c-0.2,0.5-0.9,1.4-2,2.8c-1.1,1.4-1.8,2.5-2,3.4c-0.2,0.6-0.1,1.8,0.1,3.4
-  c0.2,1.6,0.2,2.8-0.1,3.6c-0.6,3-1.8,6.7-3.6,11c-1.8,4.3-3.6,7.9-5.4,11c-0.5,0.8-1.1,1.7-2,2.8c-0.8,1.1-1.5,2-2,2.8
-  s-0.8,1.6-1,2.5c-0.1,0.5,0,1.3,0.4,2.3c0.3,1.1,0.4,1.9,0.4,2.6c-0.1,1.1-0.2,2.6-0.5,4.4c-0.2,1.8-0.4,2.9-0.4,3.2
-  c-1.8,4.8-1.7,9.9,0.2,15.2c2.2,6.2,6.2,11.5,11.9,15.8c5.7,4.3,11.7,6.4,17.8,6.4h110.7c5.2,0,10.1-1.7,14.7-5.2s7.7-7.8,9.2-12.9
-  l33-108.6c1.8-5.8,1-10.9-2.2-15.5C194.9,39.7,192.6,38,189.5,36.8z M59.6,122.8L73.8,80c0,0,7,0,10.8,0s28.8-1.7,25.4,17.5
-  c-3.4,19.2-18.8,25.2-36.8,25.4S59.6,122.8,59.6,122.8z M78.6,116.8c4.7-0.1,18.9-2.9,22.1-17.1S89.2,86.3,89.2,86.3l-8.9,0
-  l-10.2,30.5C70.2,116.9,74,116.9,78.6,116.8z M75.3,68.7L89,26.2h9.8l0.8,34l23.6-34h9.9l-13.6,42.5h-7.1l12.5-35.4l-24.5,35.4h-6.8
-  l-0.8-35L82,68.7H75.3z"/>
-</svg>
-<!-- Original image Copyright Dave Gandy — CC BY 4.0 License -->
+<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xml:space="preserve" xmlns:serif="http://www.serif.com/" style="fill-rule:evenodd;clip-rule:evenodd;stroke-linejoin:round;stroke-miterlimit:2;" viewBox="663.38 37.57 575.35 903.75">     <g transform="matrix(1,0,0,1,-31352.7,-1817.25)">                  <g transform="matrix(1,0,0,1,31062.7,-20.8972)">             <g transform="matrix(1,0,0,1,-130.173,0.00185558)">                 <path d="M1083.58,1875.72L1635.06,2194.12C1649.8,2202.63 1658.88,2218.37 1658.88,2235.39C1658.88,2264.98 1658.88,2311.74 1658.88,2341.33C1658.88,2349.84 1656.61,2358.03 1652.5,2365.16C1652.5,2365.16 1214.7,2112.4 1107.2,2050.33C1092.58,2041.89 1083.58,2026.29 1083.58,2009.41C1083.58,1963.5 1083.58,1875.72 1083.58,1875.72Z" style="fill:#706bc8;"></path>             </g>             <g transform="matrix(1,0,0,1,-130.173,0.00185558)">                 <path d="M1635.26,2604.84C1649.88,2613.28 1658.88,2628.87 1658.88,2645.75C1658.88,2691.67 1658.88,2779.44 1658.88,2779.44L1107.41,2461.05C1092.66,2452.53 1083.58,2436.8 1083.58,2419.78C1083.58,2390.19 1083.58,2343.42 1083.58,2313.84C1083.58,2305.32 1085.85,2297.13 1089.96,2290.01C1089.96,2290.01 1527.76,2542.77 1635.26,2604.84Z" style="fill:#55c5e4;"></path>             </g>             <g transform="matrix(1,0,0,1,216.062,984.098)">                 <path d="M790.407,1432.56C785.214,1435.55 780.717,1439.9 777.509,1445.46C767.862,1462.16 773.473,1483.76 790.004,1493.59L789.998,1493.59L761.173,1476.95C746.427,1468.44 737.344,1452.71 737.344,1435.68C737.344,1406.09 737.344,1359.33 737.344,1329.74C737.344,1312.71 746.427,1296.98 761.173,1288.47L1259.59,1000.74L1259.83,1000.6C1264.92,997.617 1269.33,993.314 1272.48,987.844C1282.13,971.136 1276.52,949.544 1259.99,939.707L1260,939.707L1288.82,956.349C1303.57,964.862 1312.65,980.595 1312.65,997.622C1312.65,1027.21 1312.65,1073.97 1312.65,1103.56C1312.65,1120.59 1303.57,1136.32 1288.82,1144.83L1259.19,1161.94L1259.59,1161.68L790.407,1432.56Z" style="fill:#84ddea;"></path>             </g>             <g transform="matrix(1,0,0,1,216.062,984.098)">                 <path d="M790.407,1686.24C785.214,1689.23 780.717,1693.58 777.509,1699.13C767.862,1715.84 773.473,1737.43 790.004,1747.27L789.998,1747.27L761.173,1730.63C746.427,1722.12 737.344,1706.38 737.344,1689.36C737.344,1659.77 737.344,1613.01 737.344,1583.42C737.344,1566.39 746.427,1550.66 761.173,1542.15L1259.59,1254.42L1259.83,1254.28C1264.92,1251.29 1269.33,1246.99 1272.48,1241.52C1282.13,1224.81 1276.52,1203.22 1259.99,1193.38L1260,1193.38L1288.82,1210.03C1303.57,1218.54 1312.65,1234.27 1312.65,1251.3C1312.65,1280.89 1312.65,1327.65 1312.65,1357.24C1312.65,1374.26 1303.57,1390 1288.82,1398.51L1259.19,1415.61L1259.59,1415.36L790.407,1686.24Z" style="fill:#997bc8;"></path></g></g></g> </svg>

book/theme/highlight.css

@@ -1,83 +0,0 @@
-/*
- * An increased contrast highlighting scheme loosely based on the
- * "Base16 Atelier Dune Light" theme by Bram de Haan
- * (http://atelierbram.github.io/syntax-highlighting/atelier-schemes/dune)
- * Original Base16 color scheme by Chris Kempson
- * (https://github.com/chriskempson/base16)
- */
-
-/* Comment */
-.hljs-comment,
-.hljs-quote {
-  color: #575757;
-}
-
-/* Red */
-.hljs-variable,
-.hljs-template-variable,
-.hljs-attribute,
-.hljs-tag,
-.hljs-name,
-.hljs-regexp,
-.hljs-link,
-.hljs-name,
-.hljs-selector-id,
-.hljs-selector-class {
-  color: #d70025;
-}
-
-/* Orange */
-.hljs-number,
-.hljs-meta,
-.hljs-built_in,
-.hljs-builtin-name,
-.hljs-literal,
-.hljs-type,
-.hljs-params {
-  color: #b21e00;
-}
-
-/* Green */
-.hljs-string,
-.hljs-symbol,
-.hljs-bullet {
-  color: #008200;
-}
-
-/* Blue */
-.hljs-title,
-.hljs-section {
-  color: #0030f2;
-}
-
-/* Purple */
-.hljs-keyword,
-.hljs-selector-tag {
-  color: #9d00ec;
-}
-
-.hljs {
-  display: block;
-  overflow-x: auto;
-  background: #f6f7f6;
-  color: #000;
-  padding: 0.5em;
-}
-
-.hljs-emphasis {
-  font-style: italic;
-}
-
-.hljs-strong {
-  font-weight: bold;
-}
-
-.hljs-addition {
-  color: #22863a;
-  background-color: #f0fff4;
-}
-
-.hljs-deletion {
-  color: #b31d28;
-  background-color: #ffeef0;
-}

book/theme/index.hbs

@@ -1,11 +1,11 @@
 <!DOCTYPE HTML>
-<html lang="{{ language }}" class="sidebar-visible no-js {{ default_theme }}">
+<html lang="{{ language }}" class="{{ default_theme }}" dir="{{ text_direction }}">
     <head>
         <!-- Book generated using mdBook -->
         <meta charset="UTF-8">
         <title>{{ title }}</title>
         {{#if is_print }}
-        <meta name="robots" content="noindex" />
+        <meta name="robots" content="noindex">
         {{/if}}
         {{#if base_url}}
         <base href="{{ base_url }}">
@@ -15,10 +15,9 @@
         <!-- Custom HTML head -->
         {{> head}}
 
-        <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
         <meta name="description" content="{{ description }}">
         <meta name="viewport" content="width=device-width, initial-scale=1">
-        <meta name="theme-color" content="#ffffff" />
+        <meta name="theme-color" content="#ffffff">
 
         {{#if favicon_svg}}
         <link rel="icon" href="{{ path_to_root }}favicon.svg">
@@ -35,8 +34,6 @@
 
         <!-- Fonts -->
         <link rel="stylesheet" href="{{ path_to_root }}FontAwesome/css/font-awesome.css">
-        <link rel="preconnect" href="https://fonts.gstatic.com">
-        <link href="https://fonts.googleapis.com/css2?family=Inter:wght@200;400;500;700&display=swap" rel="stylesheet">
         {{#if copy_fonts}}
         <link rel="stylesheet" href="{{ path_to_root }}fonts/fonts.css">
         {{/if}}
@@ -53,18 +50,19 @@
 
         {{#if mathjax_support}}
         <!-- MathJax -->
-        <script async type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
+        <script async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
         {{/if}}
     </head>
-    <body>
+    <body class="sidebar-visible no-js">
+    <div id="body-container">
         <!-- Provide site root to javascript -->
-        <script type="text/javascript">
+        <script>
             var path_to_root = "{{ path_to_root }}";
             var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "{{ preferred_dark_theme }}" : "{{ default_theme }}";
         </script>
 
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
-        <script type="text/javascript">
+        <script>
             try {
                 var theme = localStorage.getItem('mdbook-theme');
                 var sidebar = localStorage.getItem('mdbook-sidebar');
@@ -80,27 +78,34 @@
         </script>
 
         <!-- Set the theme before any content is loaded, prevents flash -->
-        <script type="text/javascript">
+        <script>
             var theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
             var html = document.querySelector('html');
-            html.classList.remove('no-js')
             html.classList.remove('{{ default_theme }}')
             html.classList.add(theme);
-            html.classList.add('js');
+            var body = document.querySelector('body');
+            body.classList.remove('no-js')
+            body.classList.add('js');
         </script>
 
+        <input type="checkbox" id="sidebar-toggle-anchor" class="hidden">
+
         <!-- Hide / unhide sidebar before it is displayed -->
-        <script type="text/javascript">
-            var html = document.querySelector('html');
-            var sidebar = 'hidden';
+        <script>
+            var body = document.querySelector('body');
+            var sidebar = null;
+            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
-            html.classList.remove('sidebar-visible');
-            html.classList.add("sidebar-" + sidebar);
+            sidebar_toggle.checked = sidebar === 'visible';
+            body.classList.remove('sidebar-visible');
+            body.classList.add("sidebar-" + sidebar);
         </script>
 
         <nav id="sidebar" class="sidebar" aria-label="Table of contents">
@@ -110,26 +115,48 @@
             <div id="sidebar-resize-handle" class="sidebar-resize-handle"></div>
         </nav>
 
+        <!-- Track and set sidebar scroll position -->
+        <script>
+            var sidebarScrollbox = document.querySelector('#sidebar .sidebar-scrollbox');
+            sidebarScrollbox.addEventListener('click', function(e) {
+                if (e.target.tagName === 'A') {
+                    sessionStorage.setItem('sidebar-scroll', sidebarScrollbox.scrollTop);
+                }
+            }, { passive: true });
+            var sidebarScrollTop = sessionStorage.getItem('sidebar-scroll');
+            sessionStorage.removeItem('sidebar-scroll');
+            if (sidebarScrollTop) {
+                // preserve sidebar scroll position when navigating via links within sidebar
+                sidebarScrollbox.scrollTop = sidebarScrollTop;
+            } else {
+                // scroll sidebar to current active section when navigating via "next/previous chapter" buttons
+                var activeSection = document.querySelector('#sidebar .active');
+                if (activeSection) {
+                    activeSection.scrollIntoView({ block: 'center' });
+                }
+            }
+        </script>
+
         <div id="page-wrapper" class="page-wrapper">
 
             <div class="page">
                 {{> header}}
                 <div id="menu-bar-hover-placeholder"></div>
-                <div id="menu-bar" class="menu-bar sticky bordered">
+                <div id="menu-bar" class="menu-bar sticky">
                     <div class="left-buttons">
-                        <button id="sidebar-toggle" class="icon-button" type="button" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
+                        <label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
                             <i class="fa fa-bars"></i>
-                        </button>
+                        </label>
                         <button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
                             <i class="fa fa-paint-brush"></i>
                         </button>
                         <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
-                            <li role="none"><button role="menuitem" class="theme" id="light">{{ theme_option "Light" }}</button></li>
-                            <li role="none"><button role="menuitem" class="theme" id="rust">{{ theme_option "Rust" }}</button></li>
-                            <li role="none"><button role="menuitem" class="theme" id="coal">{{ theme_option "Coal" }}</button></li>
-                            <li role="none"><button role="menuitem" class="theme" id="navy">{{ theme_option "Navy" }}</button></li>
-                            <li role="none"><button role="menuitem" class="theme" id="ayu">{{ theme_option "Ayu" }}</button></li>
-                            <li role="none"><button role="menuitem" class="theme" id="colibri">{{ theme_option "Colibri" }}</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="navy">Navy</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="ayu">Ayu</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="colibri">Colibri</button></li>
                         </ul>
                         {{#if search_enabled}}
                         <button id="search-toggle" class="icon-button" type="button" title="Search. (Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar">
@@ -151,13 +178,19 @@
                             <i id="git-repository-button" class="fa {{git_repository_icon}}"></i>
                         </a>
                         {{/if}}
+                        {{#if git_repository_edit_url}}
+                        <a href="{{git_repository_edit_url}}" title="Suggest an edit" aria-label="Suggest an edit">
+                            <i id="git-edit-button" class="fa fa-edit"></i>
+                        </a>
+                        {{/if}}
+
                     </div>
                 </div>
 
                 {{#if search_enabled}}
                 <div id="search-wrapper" class="hidden">
                     <form id="searchbar-outer" class="searchbar-outer">
-                        <input type="search" name="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
+                        <input type="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
                     </form>
                     <div id="searchresults-outer" class="searchresults-outer hidden">
                         <div id="searchresults-header" class="searchresults-header"></div>
@@ -168,7 +201,7 @@
                 {{/if}}
 
                 <!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
-                <script type="text/javascript">
+                <script>
                     document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
                     document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
                     Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
@@ -190,7 +223,7 @@
                         {{/previous}}
 
                         {{#next}}
-                            <a rel="next" href="{{ path_to_root }}{{link}}" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
+                            <a rel="next prefetch" href="{{ path_to_root }}{{link}}" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
                                 <i class="fa fa-angle-right"></i>
                             </a>
                         {{/next}}
@@ -208,7 +241,7 @@
                 {{/previous}}
 
                 {{#next}}
-                    <a rel="next" href="{{ path_to_root }}{{link}}" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
+                    <a rel="next prefetch" href="{{ path_to_root }}{{link}}" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
                         <i class="fa fa-angle-right"></i>
                     </a>
                 {{/next}}
@@ -216,10 +249,12 @@
 
         </div>
 
-        {{#if livereload}}
+        {{#if live_reload_endpoint}}
         <!-- Livereload script (if served using the cli tool) -->
-        <script type="text/javascript">
-            var socket = new WebSocket("{{{livereload}}}");
+        <script>
+            const wsProtocol = location.protocol === 'https:' ? 'wss:' : 'ws:';
+            const wsAddress = wsProtocol + "//" + location.host + "/" + "{{{live_reload_endpoint}}}";
+            const socket = new WebSocket(wsAddress);
             socket.onmessage = function (event) {
                 if (event.data === "reload") {
                     socket.close();
@@ -235,7 +270,7 @@
 
         {{#if google_analytics}}
         <!-- Google Analytics Tag -->
-        <script type="text/javascript">
+        <script>
             var localAddrs = ["localhost", "127.0.0.1", ""];
 
             // make sure we don't activate google analytics if the developer is
@@ -253,43 +288,43 @@
         {{/if}}
 
         {{#if playground_line_numbers}}
-        <script type="text/javascript">
+        <script>
             window.playground_line_numbers = true;
         </script>
         {{/if}}
 
         {{#if playground_copyable}}
-        <script type="text/javascript">
+        <script>
             window.playground_copyable = true;
         </script>
         {{/if}}
 
         {{#if playground_js}}
-        <script src="{{ path_to_root }}ace.js" type="text/javascript" charset="utf-8"></script>
-        <script src="{{ path_to_root }}editor.js" type="text/javascript" charset="utf-8"></script>
-        <script src="{{ path_to_root }}mode-rust.js" type="text/javascript" charset="utf-8"></script>
-        <script src="{{ path_to_root }}theme-dawn.js" type="text/javascript" charset="utf-8"></script>
-        <script src="{{ path_to_root }}theme-tomorrow_night.js" type="text/javascript" charset="utf-8"></script>
+        <script src="{{ path_to_root }}ace.js"></script>
+        <script src="{{ path_to_root }}editor.js"></script>
+        <script src="{{ path_to_root }}mode-rust.js"></script>
+        <script src="{{ path_to_root }}theme-dawn.js"></script>
+        <script src="{{ path_to_root }}theme-tomorrow_night.js"></script>
         {{/if}}
 
         {{#if search_js}}
-        <script src="{{ path_to_root }}elasticlunr.min.js" type="text/javascript" charset="utf-8"></script>
-        <script src="{{ path_to_root }}mark.min.js" type="text/javascript" charset="utf-8"></script>
-        <script src="{{ path_to_root }}searcher.js" type="text/javascript" charset="utf-8"></script>
+        <script src="{{ path_to_root }}elasticlunr.min.js"></script>
+        <script src="{{ path_to_root }}mark.min.js"></script>
+        <script src="{{ path_to_root }}searcher.js"></script>
         {{/if}}
 
-        <script src="{{ path_to_root }}clipboard.min.js" type="text/javascript" charset="utf-8"></script>
-        <script src="{{ path_to_root }}highlight.js" type="text/javascript" charset="utf-8"></script>
-        <script src="{{ path_to_root }}book.js" type="text/javascript" charset="utf-8"></script>
+        <script src="{{ path_to_root }}clipboard.min.js"></script>
+        <script src="{{ path_to_root }}highlight.js"></script>
+        <script src="{{ path_to_root }}book.js"></script>
 
         <!-- Custom JS scripts -->
         {{#each additional_js}}
-        <script type="text/javascript" src="{{ ../path_to_root }}{{this}}"></script>
+        <script src="{{ ../path_to_root }}{{this}}"></script>
         {{/each}}
 
         {{#if is_print}}
         {{#if mathjax_support}}
-        <script type="text/javascript">
+        <script>
         window.addEventListener('load', function() {
             MathJax.Hub.Register.StartupHook('End', function() {
                 window.setTimeout(window.print, 100);
@@ -297,7 +332,7 @@
         });
         </script>
         {{else}}
-        <script type="text/javascript">
+        <script>
         window.addEventListener('load', function() {
             window.setTimeout(window.print, 100);
         });
@@ -305,5 +340,6 @@
         {{/if}}
         {{/if}}
 
+    </div>
     </body>
 </html>

contrib/Helix.appdata.xml

@@ -0,0 +1,108 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<component type="desktop-application">
+  <id>com.helix_editor.Helix</id>
+  <metadata_license>CC0-1.0</metadata_license>
+  <project_license>MPL-2.0</project_license>
+  <name>Helix</name>
+  <summary>A post-modern text editor</summary>
+  <summary xml:lang="ar">مُحَرِّرُ نُصُوصٍ سَابِقٌ لِعَهدِه</summary>
+
+  <description>
+    <p>
+      Helix is a terminal-based text editor inspired by Kakoune / Neovim and written in Rust.
+    </p>
+    <ul>
+      <li>Vim-like modal editing</li>
+      <li>Multiple selections</li>
+      <li>Built-in language server support</li>
+      <li>Smart, incremental syntax highlighting and code editing via tree-sitter</li>
+    </ul>
+  </description>
+  <description xml:lang="ar">
+    <p>
+      مُحَرِّرُ نُصُوصٍ يَعمَلُ فِي الطَّرَفِيَّة، مُستَلهَمٌ مِن Kakoune وَ Neovim وَمَكتُوبٌ بِلُغَةِ رَست البَرمَجِيَّة.
+    </p>
+    <ul>
+      <li>تَحرِيرٌ وَضعِيٌّ شَبيهٌ بِـVim</li>
+      <li>تَحدِيدَاتٌ لِلنَّصِ مُتَعَدِّدَة</li>
+      <li>دَعْمٌ مُدمَجٌ لِخَوادِمِ اللُّغَات</li>
+      <li>تَحرِيرُ التَّعلِيمَاتِ البَّرمَجِيَّةِ مَعَ تَمييزٍ لِلتَّركِيبِ النَّحُويِّ بِواسِطَةِ tree-sitter</li>
+    </ul>
+  </description>
+
+  <launchable type="desktop-id">Helix.desktop</launchable>
+
+  <screenshots>
+    <screenshot type="default">
+      <caption>Helix with default theme</caption>
+      <image>https://github.com/helix-editor/helix/raw/d4565b4404cabc522bd60822abd374755581d751/screenshot.png</image>
+    </screenshot>
+  </screenshots>
+
+  <url type="homepage">https://helix-editor.com/</url>
+  <url type="donation">https://opencollective.com/helix-editor</url>
+  <url type="help">https://docs.helix-editor.com/</url>
+  <url type="vcs-browser">https://github.com/helix-editor/helix</url>
+  <url type="bugtracker">https://github.com/helix-editor/helix/issues</url>
+
+  <content_rating type="oars-1.1" />
+
+  <releases>
+    <release version="23.10" date="2023-10-24">
+      <url>https://helix-editor.com/news/release-23-10-highlights/</url>
+    </release>
+    <release version="23.05" date="2023-05-18">
+      <url>https://github.com/helix-editor/helix/releases/tag/23.05</url>
+    </release>
+    <release version="23.03" date="2023-03-31">
+      <url>https://helix-editor.com/news/release-23-03-highlights/</url>
+    </release>
+    <release version="22.12" date="2022-12-6">
+      <url>https://helix-editor.com/news/release-22-12-highlights/</url>
+    </release>
+    <release version="22.08" date="2022-8-31">
+      <url>https://helix-editor.com/news/release-22-08-highlights/</url>
+    </release>
+    <release version="22.05" date="2022-5-28">
+      <url>https://helix-editor.com/news/release-22-05-highlights/</url>
+    </release>
+    <release version="22.03" date="2022-3-28">
+      <url>https://helix-editor.com/news/release-22-03-highlights/</url>
+    </release>
+  </releases>
+
+  <requires>
+    <control>keyboard</control>
+  </requires>
+
+  <categories>
+    <category>Utility</category>
+    <category>TextEditor</category>
+  </categories>
+
+  <keywords>
+    <keyword>text</keyword>
+    <keyword>editor</keyword>
+    <keyword>development</keyword>
+    <keyword>programming</keyword>
+  </keywords>
+
+  <provides>
+    <binary>hx</binary>
+    <mediatype>text/english</mediatype>
+    <mediatype>text/plain</mediatype>
+    <mediatype>text/x-makefile</mediatype>
+    <mediatype>text/x-c++hdr</mediatype>
+    <mediatype>text/x-c++src</mediatype>
+    <mediatype>text/x-chdr</mediatype>
+    <mediatype>text/x-csrc</mediatype>
+    <mediatype>text/x-java</mediatype>
+    <mediatype>text/x-moc</mediatype>
+    <mediatype>text/x-pascal</mediatype>
+    <mediatype>text/x-tcl</mediatype>
+    <mediatype>text/x-tex</mediatype>
+    <mediatype>application/x-shellscript</mediatype>
+    <mediatype>text/x-c</mediatype>
+    <mediatype>text/x-c++</mediatype>
+  </provides>
+</component>

contrib/Helix.desktop

@@ -0,0 +1,91 @@
+[Desktop Entry]
+Name=Helix
+GenericName=Text Editor
+GenericName[ar]=مُحَرِّرُ نُصُوص
+GenericName[de]=Texteditor
+GenericName[fr]=Éditeur de texte
+GenericName[ru]=Текстовый редактор
+GenericName[sr]=Едитор текст
+GenericName[tr]=Metin Düzenleyici
+Comment=Edit text files
+Comment[af]=Redigeer tekslêers
+Comment[am]=የጽሑፍ ፋይሎች ያስተካክሉ
+Comment[ar]=مُحَرِّرُ مِلَفَّاتٍ نَصِّيَّة
+Comment[az]=Mətn fayllarını redaktə edin
+Comment[be]=Рэдагаваньне тэкставых файлаў
+Comment[bg]=Редактиране на текстови файлове
+Comment[bn]=টেক্স্ট ফাইল এডিট করুন
+Comment[bs]=Izmijeni tekstualne datoteke
+Comment[ca]=Edita fitxers de text
+Comment[cs]=Úprava textových souborů
+Comment[cy]=Golygu ffeiliau testun
+Comment[da]=Redigér tekstfiler
+Comment[de]=Textdateien bearbeiten
+Comment[el]=Επεξεργασία αρχείων κειμένου
+Comment[en_CA]=Edit text files
+Comment[en_GB]=Edit text files
+Comment[es]=Edita archivos de texto
+Comment[et]=Redigeeri tekstifaile
+Comment[eu]=Editatu testu-fitxategiak
+Comment[fa]=ویرایش پرونده‌های متنی
+Comment[fi]=Muokkaa tekstitiedostoja
+Comment[fr]=Éditer des fichiers texte
+Comment[ga]=Eagar comhad Téacs
+Comment[gu]=લખાણ ફાઇલોમાં ફેરફાર કરો
+Comment[he]=ערוך קבצי טקסט
+Comment[hi]=पाठ फ़ाइलें संपादित करें
+Comment[hr]=Uređivanje tekstualne datoteke
+Comment[hu]=Szövegfájlok szerkesztése
+Comment[id]=Edit file teks
+Comment[it]=Modifica file di testo
+Comment[ja]=テキストファイルを編集します
+Comment[kn]=ಪಠ್ಯ ಕಡತಗಳನ್ನು ಸಂಪಾದಿಸು
+Comment[ko]=텍스트 파일을 편집합니다
+Comment[lt]=Redaguoti tekstines bylas
+Comment[lv]=Rediģēt teksta failus
+Comment[mk]=Уреди текстуални фајлови
+Comment[ml]=വാചക രചനകള് തിരുത്തുക
+Comment[mn]=Текст файл боловсруулах
+Comment[mr]=गद्य फाइल संपादित करा
+Comment[ms]=Edit fail teks
+Comment[nb]=Rediger tekstfiler
+Comment[ne]=पाठ फाइललाई संशोधन गर्नुहोस्
+Comment[nl]=Tekstbestanden bewerken
+Comment[nn]=Rediger tekstfiler
+Comment[no]=Rediger tekstfiler
+Comment[or]=ପାଠ୍ଯ ଫାଇଲଗୁଡ଼ିକୁ ସମ୍ପାଦନ କରନ୍ତୁ
+Comment[pa]=ਪਾਠ ਫਾਇਲਾਂ ਸੰਪਾਦਨ
+Comment[pl]=Edytor plików tekstowych
+Comment[pt]=Editar ficheiros de texto
+Comment[pt_BR]=Edite arquivos de texto
+Comment[ro]=Editare fişiere text
+Comment[ru]=Редактирование текстовых файлов
+Comment[sk]=Úprava textových súborov
+Comment[sl]=Urejanje datotek z besedili
+Comment[sq]=Përpuno files teksti
+Comment[sr]=Уређујте текст фајлове
+Comment[sr@Latn]=Izmeni tekstualne datoteke
+Comment[sv]=Redigera textfiler
+Comment[ta]=உரை கோப்புகளை தொகுக்கவும்
+Comment[th]=แก้ไขแฟ้มข้อความ
+Comment[tk]=Metin faýllary editle
+Comment[tr]=Metin dosyaları düzenleyin
+Comment[uk]=Редактор текстових файлів
+Comment[vi]=Soạn thảo tập tin văn bản
+Comment[wa]=Asspougnî des fitchîs tecses
+Comment[zh_CN]=编辑文本文件
+Comment[zh_TW]=編輯文字檔
+TryExec=hx
+Exec=hx %F
+Terminal=true
+Type=Application
+Keywords=Text;editor;
+Keywords[ar]=نص;نصوص;محرر;
+Keywords[fr]=Texte;éditeur;
+Keywords[ru]=текст;текстовый редактор;
+Keywords[sr]=Текст;едитор;
+Keywords[tr]=Metin;düzenleyici;
+Icon=helix
+Categories=Utility;TextEditor;
+StartupNotify=false
+MimeType=text/english;text/plain;text/x-makefile;text/x-c++hdr;text/x-c++src;text/x-chdr;text/x-csrc;text/x-java;text/x-moc;text/x-pascal;text/x-tcl;text/x-tex;application/x-shellscript;text/x-c;text/x-c++;

contrib/completion/hx.bash

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+# Bash completion script for Helix editor
+
+_hx() {
+	# $1 command name
+	# $2 word being completed
+	# $3 word preceding
+	COMPREPLY=()
+
+	case "$3" in
+	-g | --grammar)
+		COMPREPLY=($(compgen -W "fetch build" -- $2))
+		;;
+	--health)
+		local languages=$(hx --health |tail -n '+7' |awk '{print $1}' |sed 's/\x1b\[[0-9;]*m//g')
+		COMPREPLY=($(compgen -W "$languages" -- $2))
+		;;
+	*)
+		COMPREPLY=($(compgen -fd -W "-h --help --tutor -V --version -v -vv -vvv --health -g --grammar --vsplit --hsplit -c --config --log" -- $2))
+		;;
+	esac
+} && complete -o filenames -F _hx hx
+

contrib/completion/hx.elv

@@ -0,0 +1,55 @@
+# You can move it here ~/.config/elvish/lib/hx.elv
+# Or add `eval (slurp < ~/$REPOS/helix/contrib/completion/hx.elv)`
+# Be sure to replace `$REPOS` with something that makes sense for you!
+
+### Renders a pretty completion candidate
+var candidate = { | _stem  _desc | 
+  edit:complex-candidate $_stem &display=(styled $_stem bold)(styled " "$_desc dim)
+}
+
+### These commands will invalidate further input (i.e. not react to them)
+var skips = [ "--tutor" "--help" "--version" "-V" "--health" ]
+
+### Grammar commands
+var grammar = [ "--grammar" "-g" ]
+
+### Config commands
+var config = [ "--config" "-c" ]
+
+### Set an arg-completer for the `hx` binary
+set edit:completion:arg-completer[hx] = {|@args|
+  var n = (count $args)
+  if (>= $n 3) {
+    # Stop completions if passed arg will take presedence
+    # and invalidate further input
+    if (has-value $skips $args[-2]) {
+      return
+    } 
+    # If the previous arg == --grammar, then only suggest:
+    if (has-value $grammar $args[-2]) {
+      $candidate "fetch" "Fetch the tree-sitter grammars"
+      $candidate "build" "Build the tree-sitter grammars"
+      return
+    } 
+    # When we have --config, we need a file
+    if (has-values $config $args[-2]) {
+      edit:complete-filename $args[-1] | each { |v| put $v[stem] }
+      return
+    } 
+    # When we have --log, we need a file
+    if (has-values "log" $args[-2]) {
+      edit:complete-filename $args[-1] | each { |v| put $v[stem] }
+      return
+    } 
+  } 
+  edit:complete-filename $args[-1] | each { |v| put $v[stem]}
+  $candidate "--help" "(Prints help information)"
+  $candidate "--version" "(Prints version information)"
+  $candidate "--tutor" "(Loads the tutorial)"
+  $candidate "--health" "(Checks for errors in editor setup)"
+  $candidate "--grammar" "(Fetch or build the tree-sitter grammars)"
+  $candidate "--vsplit" "(Splits all given files vertically)"
+  $candidate "--hsplit" "(Splits all given files horizontally)"
+  $candidate "--config" "(Specifies a file to use for configuration)"
+  $candidate "--log" "(Specifies a file to write log data into)"
+}

contrib/completion/hx.fish

@@ -0,0 +1,15 @@
+#!/usr/bin/env fish
+# Fish completion script for Helix editor
+
+set -l langs (hx --health |tail -n '+7' |awk '{print $1}' |sed 's/\x1b\[[0-9;]*m//g')
+
+complete -c hx -s h -l help -d "Prints help information"
+complete -c hx -l tutor -d "Loads the tutorial"
+complete -c hx -l health -x -a "$langs" -d "Checks for errors in editor setup"
+complete -c hx -s g -l grammar -x -a "fetch build" -d "Fetches or builds tree-sitter grammars"
+complete -c hx -s v -o vv -o vvv -d "Increases logging verbosity"
+complete -c hx -s V -l version -d "Prints version information"
+complete -c hx -l vsplit -d "Splits all given files vertically into different windows"
+complete -c hx -l hsplit -d "Splits all given files horizontally into different windows"
+complete -c hx -s c -l config -r -d "Specifies a file to use for completion"
+complete -c hx -l log -r -d "Specifies a file to write log data into"

contrib/completion/hx.zsh

@@ -0,0 +1,34 @@
+#compdef _hx hx
+# Zsh completion script for Helix editor
+
+_hx() {
+	_arguments -C \
+		"-h[Prints help information]" \
+		"--help[Prints help information]" \
+		"-v[Increase logging verbosity]" \
+		"-vv[Increase logging verbosity]" \
+		"-vvv[Increase logging verbosity]" \
+		"-V[Prints version information]" \
+		"--version[Prints version information]" \
+		"--tutor[Loads the tutorial]" \
+		"--health[Checks for errors in editor setup]:language:->health" \
+		"-g[Fetches or builds tree-sitter grammars]:action:->grammar" \
+		"--grammar[Fetches or builds tree-sitter grammars]:action:->grammar" \
+		"--vsplit[Splits all given files vertically into different windows]" \
+		"--hsplit[Splits all given files horizontally into different windows]" \
+		"-c[Specifies a file to use for configuration]" \
+		"--config[Specifies a file to use for configuration]" \
+		"--log[Specifies a file to write log data into]" \
+		"*:file:_files"
+
+	case "$state" in
+	health)
+		local languages=($(hx --health |tail -n '+7' |awk '{print $1}' |sed 's/\x1b\[[0-9;]*m//g'))
+		_values 'language' $languages
+		;;
+	grammar)
+		_values 'action' fetch build
+		;;
+	esac
+}
+

contrib/themes

@@ -0,0 +1 @@
+../runtime/themes

default.nix

@@ -0,0 +1,8 @@
+# Flake's default package for non-flake-enabled nix instances
+let
+  compat = builtins.fetchTarball {
+    url = "https://github.com/edolstra/flake-compat/archive/b4a34015c698c7793d592d66adbab377907a2be8.tar.gz";
+    sha256 = "sha256:1qc703yg0babixi6wshn5wm2kgl5y1drcswgszh4xxzbrwkk9sv7";
+  };
+in
+  (import compat {src = ./.;}).defaultNix.default

docs/CONTRIBUTING.md

@@ -0,0 +1,68 @@
+# Contributing
+
+Contributors are very welcome! **No contribution is too small and all contributions are valued.**
+
+Some suggestions to get started:
+
+- You can look at the [good first issue][good-first-issue] label on the issue tracker.
+- Help with packaging on various distributions needed!
+- To use print debugging to the [Helix log file][log-file], you must:
+  * Print using `log::info!`, `warn!`, or `error!`. (`log::info!("helix!")`)
+  * Pass the appropriate verbosity level option for the desired log level. (`hx -v <file>` for info, more `v`s for higher verbosity)
+  * Want to display the logs in a separate file instead of using the `:log-open` command in your compiled Helix editor? Start your debug version with `cargo run -- --log foo.log` and in a new terminal use `tail -f foo.log`
+- Instead of running a release version of Helix, while developing you may want to run in debug mode with `cargo run` which is way faster to compile
+- Looking for even faster compile times? Give a try to [mold](https://github.com/rui314/mold)
+- If your preferred language is missing, integrating a tree-sitter grammar for
+    it and defining syntax highlight queries for it is straight forward and
+    doesn't require much knowledge of the internals.
+
+We provide an [architecture.md][architecture.md] that should give you
+a good overview of the internals.
+
+# Auto generated documentation
+
+Some parts of [the book][docs] are autogenerated from the code itself,
+like the list of `:commands` and supported languages. To generate these
+files, run
+
+```shell
+cargo xtask docgen
+```
+
+inside the project. We use [xtask][xtask] as an ad-hoc task runner.
+
+To preview the book itself, install [mdbook][mdbook]. Then, run
+
+```shell
+mdbook serve book
+```
+
+and visit [http://localhost:3000](http://localhost:3000).
+
+# Testing
+
+## Unit tests/Documentation tests
+
+Run `cargo test --workspace` to run unit tests and documentation tests in all packages.
+
+## Integration tests
+
+Integration tests for helix-term can be run with `cargo integration-test`. Code
+contributors are strongly encouraged to write integration tests for their code.
+Existing tests can be used as examples. Helpers can be found in
+[helpers.rs][helpers.rs]. The log level can be set with the `HELIX_LOG_LEVEL`
+environment variable, e.g. `HELIX_LOG_LEVEL=debug cargo integration-test`.
+
+## Minimum Stable Rust Version (MSRV) Policy
+
+Helix follows the MSRV of Firefox.
+The current MSRV and future changes to the MSRV are listed in the [Firefox documentation].
+
+[Firefox documentation]: https://firefox-source-docs.mozilla.org/writing-rust-code/update-policy.html
+[good-first-issue]: https://github.com/helix-editor/helix/labels/E-easy
+[log-file]: https://github.com/helix-editor/helix/wiki/FAQ#access-the-log-file
+[architecture.md]: ./architecture.md
+[docs]: https://docs.helix-editor.com/
+[xtask]: https://github.com/matklad/cargo-xtask
+[mdbook]: https://rust-lang.github.io/mdBook/guide/installation.html
+[helpers.rs]: ../helix-term/tests/test/helpers.rs

docs/architecture.md

@@ -1,75 +1,111 @@
 
-| Crate        | Description                                            |
-| -----------  | -----------                                            |
-| helix-core   | Core editing primitives, functional.                   |
-| helix-syntax | Tree-sitter grammars                                   |
-| helix-lsp    | Language server client                                 |
-| helix-view   | UI abstractions for use in backends, imperative shell. |
-| helix-term   | Terminal UI                                            |
-| helix-tui    | TUI primitives, forked from tui-rs, inspired by Cursive |
+| Crate        | Description                                                      |
+| -----------  | -----------                                                      |
+| helix-core   | Core editing primitives, functional.                             |
+| helix-lsp    | Language server client                                           |
+| helix-dap    | Debug Adapter Protocol (DAP) client                              |
+| helix-loader | Functions for building, fetching, and loading external resources |
+| helix-view   | UI abstractions for use in backends, imperative shell.           |
+| helix-term   | Terminal UI                                                      |
+| helix-tui    | TUI primitives, forked from tui-rs, inspired by Cursive          |
 
-# Notes
 
-- server-client architecture via gRPC, UI separate from core
-- multi cursor based editing and slicing
-- WASM based plugins (builtin LSP & fuzzy file finder)
+This document contains a high-level overview of Helix internals.
 
-Structure similar to codemirror:
+> NOTE: Use `cargo doc --open` for API documentation as well as dependency
+> documentation.
 
-- text (ropes)
-- transactions
-  - changes
-  - invert changes (generates a revert)
-  - annotations (time changed etc)
-  - state effects
-  - additional editor state as facets
-- snapshots as an async view into current state
-- selections { anchor (nonmoving), head (moving) from/to } -> SelectionSet with a primary
-  - cursor is just a single range selection
-- markers
-  track a position inside text that synchronizes with edits
-- { doc, selection, update(), splice, changes(), facets, tabSize, identUnit, lineSeparator, changeFilter/transactionFilter to modify stuff before }
-- view (actual UI)
-- viewport(Lines) -> what's actually visible
-- extend the view via Decorations (inline styling) or Components (UI)
-    - mark / wieget / line / replace decoration
-- commands (transform state)
-- movement
-- selection extension
-- deletion
-- indentation
-- keymap (maps keys to commands)
-- history (undo tree via immutable ropes)
-  - undoes transactions via reverts
-- (collab mode)
-- gutter (line numbers, diagnostic marker, etc) -> ties into UI components
-- rangeset/span -> mappable over changes (can be a marker primitive?)
-- syntax (treesitter)
-- fold
-- selections (select mode/multiselect)
-- matchbrackets
-- closebrackets
-- special-chars (shows dots etc for specials)
-- panel (for UI: file pickers, search dialogs, etc)
-- tooltip (for UI)
-- search (regex)
-- lint (async linters)
-- lsp
-- highlight
-- stream-syntax
-- autocomplete
-- comment (gc, etc for auto commenting)
-- snippets
-- terminal mode?
+## Core
 
-- plugins can contain more commands/ui abstractions to use elsewhere
-- languageData as presets for each language (syntax, indent, comment, etc)
+The core contains basic building blocks used to construct the editor. It is
+heavily based on [CodeMirror 6](https://codemirror.net/6/docs/). The primitives
+are functional: most operations won't modify data in place but instead return
+a new copy.
 
-Vim stuff:
-- motions/operators/text objects
-- full visual mode
-- macros
-- jump lists
-- marks
-- yank/paste
-- conceal for markdown markers, etc
+The main data structure used for representing buffers is a `Rope`. We re-export
+the excellent [ropey](https://github.com/cessen/ropey) library. Ropes are cheap
+to clone, and allow us to easily make snapshots of a text state.
+
+Multiple selections are a core editing primitive. Document selections are
+represented by a `Selection`. Each `Range` in the selection consists of a moving
+`head` and an immovable `anchor`. A single cursor in the editor is simply
+a selection with a single range, with the head and the anchor in the same
+position.
+
+Ropes are modified by constructing an OT-like `Transaction`. It represents
+a single coherent change to the document and can be applied to the rope.
+A transaction can be inverted to produce an undo. Selections and marks can be
+mapped over a transaction to translate to a position in the new text state after
+applying the transaction.
+
+> NOTE: `Transaction::change`/`Transaction::change_by_selection` is the main
+> interface used to generate text edits.
+
+`Syntax` is the interface used to interact with tree-sitter ASTs for syntax
+highlighting and other features.
+
+## View
+
+The `view` layer was supposed to be a frontend-agnostic imperative library that
+would build on top of `core` to provide the common editor logic. Currently it's
+tied to the terminal UI.
+
+A `Document` ties together the `Rope`, `Selection`(s), `Syntax`, document
+`History`, language server (etc.) into a comprehensive representation of an open
+file.
+
+A `View` represents an open split in the UI. It holds the currently open
+document ID and other related state. Views encapsulate the gutter, status line,
+diagnostics, and the inner area where the code is displayed.
+
+> NOTE: Multiple views are able to display the same document, so the document
+> contains selections for each view. To retrieve, `document.selection()` takes
+> a `ViewId`.
+
+`Info` is the autoinfo box that shows hints when awaiting another key with bindings
+like `g` and `m`. It is attached to the viewport as a whole.
+
+`Surface` is like a buffer to which widgets draw themselves to, and the
+surface is then rendered on the screen on each cycle.
+
+`Rect`s are areas (simply an x and y coordinate with the origin at the
+screen top left and then a height and width) which are part of a
+`Surface`. They can be used to limit the area to which a `Component` can
+render. For example if we wrap a `Markdown` component in a `Popup`
+(think the documentation popup with space+k), Markdown's render method
+will get a Rect that is the exact size of the popup.
+
+Widgets are called `Component`s internally, and you can see most of them
+in `helix-term/src/ui`. Some components like `Popup` and `Overlay` can take
+other components as children.
+
+`Layer`s are how multiple components are displayed, and is simply a
+`Vec<Component>`. Layers are managed by the `Compositor`. On each top
+level render call, the compositor renders each component in the order
+they were pushed into the stack. This makes multiple components "layer"
+on top of one another. Hence we get a file picker displayed over the
+editor, etc.
+
+The `Editor` holds the global state: all the open documents, a tree
+representation of all the view splits, the configuration, and a registry of 
+language servers. To open or close files, interact with the editor.
+
+## LSP
+
+A language server protocol client.
+
+## Term
+
+The terminal frontend.
+
+The `main` function sets up a new `Application` that runs the event loop.
+
+`commands.rs` is probably the most interesting file. It contains all commands
+(actions tied to keybindings). 
+
+`keymap.rs` links commands to key combinations.
+
+
+## TUI / Term
+
+TODO: document Component and rendering related stuff

docs/releases.md

@@ -0,0 +1,67 @@
+## Checklist
+
+Helix releases are versioned in the Calendar Versioning scheme:
+`YY.0M(.MICRO)`, for example, `22.05` for May of 2022, or in a patch release,
+`22.05.1`. In these instructions we'll use `<tag>` as a placeholder for the tag
+being published.
+
+* Merge the changelog PR
+* Add new `<release>` entry in `contrib/Helix.appdata.xml` with release information according to the [AppStream spec](https://www.freedesktop.org/software/appstream/docs/sect-Metadata-Releases.html)
+* Tag and push
+    * `git tag -s -m "<tag>" -a <tag> && git push`
+    * Make sure to switch to master and pull first
+* Edit the `Cargo.toml` file and change the date in the `version` field to the next planned release
+    * Due to Cargo having a strict requirement on SemVer with 3 or more version
+      numbers, a `0` is required in the micro version; however, unless we are
+      publishing a patch release after a major release, the `.0` is dropped in
+      the user facing version.
+    * Releases are planned to happen every two months, so `22.05.0` would change to `22.07.0`
+    * If we are pushing a patch/bugfix release in the same month as the previous
+      release, bump the micro version, e.g. `22.07.0` to `22.07.1`
+* Wait for the Release CI to finish
+    * It will automatically turn the git tag into a GitHub release when it uploads artifacts
+* Edit the new release
+    * Use `<tag>` as the title
+    * Link to the changelog and release notes
+* Merge the release notes PR
+* Download the macos and linux binaries and update the `sha256`s in the [homebrew formula]
+    * Use `sha256sum` on the downloaded `.tar.xz` files to determine the hash
+* Link to the release notes in this-week-in-rust
+    * [Example PR](https://github.com/rust-lang/this-week-in-rust/pull/3300)
+* Post to reddit
+    * [Example post](https://www.reddit.com/r/rust/comments/uzp5ze/helix_editor_2205_released/)
+
+[homebrew formula]: https://github.com/Homebrew/homebrew-core/blob/master/Formula/helix.rb
+
+## Changelog Curation
+
+The changelog is currently created manually by reading through commits in the
+log since the last release. GitHub's compare view is a nice way to approach
+this. For example, when creating the 22.07 release notes, this compare link
+may be used
+
+```
+https://github.com/helix-editor/helix/compare/22.05...master
+```
+
+Either side of the triple-dot may be replaced with an exact revision, so if
+you wish to incrementally compile the changelog, you can tackle a weeks worth
+or so, record the revision where you stopped, and use that as a starting point
+next week:
+
+```
+https://github.com/helix-editor/helix/compare/7706a4a0d8b67b943c31d0c5f7b00d357b5d838d...master
+```
+
+A work-in-progress commit for a changelog might look like
+[this example](https://github.com/helix-editor/helix/commit/831adfd4c709ca16b248799bfef19698d5175e55).
+
+Not every PR or commit needs a blurb in the changelog. Each release section
+tends to have a blurb that links to a GitHub comparison between release
+versions for convenience:
+
+> As usual, the following is a summary of each of the changes since the last
+> release. For the full log, check out the git log.
+
+Typically, small changes like dependencies or documentation updates, refactors,
+or meta changes like GitHub Actions work are left out.

docs/vision.md

@@ -0,0 +1,24 @@
+The Helix project still has a ways to go before reaching its goals.  This document outlines some of those goals and the overall vision for the project.
+
+# Vision
+
+An efficient, batteries-included editor you can take anywhere and be productive... if it's your kind of thing.
+
+* **Cross-platform.**  Whether on Linux, Windows, or OSX, you should be able to take your editor with you.
+* **Terminal first.**  Not all environments have a windowing system, and you shouldn't have to abandon your preferred editor in those cases.
+* **Native.**  No Electron or HTML DOM here.  We want an efficient, native-compiled editor that can run with minimal resources when needed.  If you're working on a Raspberry Pi, your editor shouldn't consume half of your RAM.
+* **Batteries included.**  Both the default configuration and bundled features should be enough to have a good editing experience and be productive.  You shouldn't need a massive custom config or external executables and plugins for basic features and functionality.
+* **Don't try to be everything for everyone.**  There are many great editors out there to choose from.  Let's make Helix *one of* those great options, with its own take on things.
+
+# Goals
+
+Vision statements are all well and good, but are also vague and subjective.  Here is a (non-exhaustive) list of some of Helix's more concrete goals, to help give a clearer idea of the project's direction:
+
+* **Modal.**  Vim is a great idea.
+* **Selection -> Action**, not Verb -> Object.  Interaction models aren't linguistics, and "selection first" lets you see what you're doing (among other benefits).
+* **We aren't playing code golf.**  It's more important for the keymap to be consistent and easy to memorize than it is to save a key stroke or two when editing.
+* **Built-in tools** for working with code bases efficiently.  Most projects aren't a single file, and an editor should handle that as a first-class use case.  In Helix's case, this means (among other things) a fuzzy-search file navigator and LSP support.
+* **Edit anything** that comes up when coding, within reason.  Whether it's a 200 MB XML file, a megabyte of minified javascript on a single line, or Japanese text encoded in ShiftJIS, you should be able to open it and edit it without problems.  (Note: this doesn't mean handle every esoteric use case.  Sometimes you do just need a specialized tool, and Helix isn't that.)
+* **Configurable**, within reason.  Although the defaults should be good, not everyone will agree on what "good" is.  Within the bounds of Helix's core interaction models, it should be reasonably configurable so that it can be "good" for more people.  This means, for example, custom key maps among other things.
+* **Extensible**, within reason.  Although we want Helix to be productive out-of-the-box, it's not practical or desirable to cram every useful feature and use case into the core editor.  The basics should be built-in, but you should be able to extend it with additional functionality as needed.
+* **Clean code base.**  Sometimes other factors (e.g. significant performance gains, important features, correctness, etc.) will trump strict readability, but we nevertheless want to keep the code base straightforward and easy to understand to the extent we can.

flake.lock

@@ -1,73 +1,50 @@
 {
   "nodes": {
-    "flake-utils": {
-      "locked": {
-        "lastModified": 1619345332,
-        "narHash": "sha256-qHnQkEp1uklKTpx3MvKtY6xzgcqXDsz5nLilbbuL+3A=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "2ebf2558e5bf978c7fb8ea927dfaed8fefab2e28",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
-    "flake-utils_2": {
-      "locked": {
-        "lastModified": 1614513358,
-        "narHash": "sha256-LakhOx3S1dRjnh0b5Dg3mbZyH0ToC9I8Y2wKSkBaTzU=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "5466c5bbece17adaab2d82fae80b46e807611bf3",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
-    "naersk": {
+    "crane": {
       "inputs": {
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": [
+          "nixpkgs"
+        ]
       },
       "locked": {
-        "lastModified": 1620316130,
-        "narHash": "sha256-sU0VS5oJS1FsHsZsLELAXc7G2eIelVuucRw+q5B1x9k=",
-        "owner": "nmattia",
-        "repo": "naersk",
-        "rev": "a3f40fe42cc6d267ff7518fa3199e99ff1444ac4",
+        "lastModified": 1701025348,
+        "narHash": "sha256-42GHmYH+GF7VjwGSt+fVT1CQuNpGanJbNgVHTAZppUM=",
+        "owner": "ipetkov",
+        "repo": "crane",
+        "rev": "42afaeb1a0325194a7cdb526332d2cb92fddd07b",
         "type": "github"
       },
       "original": {
-        "owner": "nmattia",
-        "repo": "naersk",
+        "owner": "ipetkov",
+        "repo": "crane",
+        "type": "github"
+      }
+    },
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
         "type": "github"
       }
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1619775165,
-        "narHash": "sha256-2qaBErjxuWpTIq6Yee5GJmhr84hmzBotLQ0ayg1VXg8=",
-        "path": "/nix/store/gs997rgx3pvdgcb54wd3fi9wbnznd9g4-source",
-        "rev": "849b29b4f76d66ec7aeeeed699b7e27ef3db7c02",
-        "type": "path"
-      },
-      "original": {
-        "id": "nixpkgs",
-        "type": "indirect"
-      }
-    },
-    "nixpkgs_2": {
-      "locked": {
-        "lastModified": 1620252427,
-        "narHash": "sha256-U1Q5QceuT4chJTJ1UOt7bZOn9Y2o5/7w27RISjqXoQw=",
+        "lastModified": 1700794826,
+        "narHash": "sha256-RyJTnTNKhO0yqRpDISk03I/4A67/dp96YRxc86YOPgU=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "d3ba49889a76539ea0f7d7285b203e7f81326ded",
+        "rev": "5a09cb4b393d58f9ed0d9ca1555016a8543c2ac8",
         "type": "github"
       },
       "original": {
@@ -77,40 +54,29 @@
         "type": "github"
       }
     },
-    "nixpkgs_3": {
-      "locked": {
-        "lastModified": 1617325113,
-        "narHash": "sha256-GksR0nvGxfZ79T91UUtWjjccxazv6Yh/MvEJ82v1Xmw=",
-        "owner": "nixos",
-        "repo": "nixpkgs",
-        "rev": "54c1e44240d8a527a8f4892608c4bce5440c3ecb",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
     "root": {
       "inputs": {
+        "crane": "crane",
         "flake-utils": "flake-utils",
-        "naersk": "naersk",
-        "nixpkgs": "nixpkgs_2",
+        "nixpkgs": "nixpkgs",
         "rust-overlay": "rust-overlay"
       }
     },
     "rust-overlay": {
       "inputs": {
-        "flake-utils": "flake-utils_2",
-        "nixpkgs": "nixpkgs_3"
+        "flake-utils": [
+          "flake-utils"
+        ],
+        "nixpkgs": [
+          "nixpkgs"
+        ]
       },
       "locked": {
-        "lastModified": 1620355527,
-        "narHash": "sha256-mUTnUODiAtxH83gbv7uuvCbqZ/BNkYYk/wa3MkwrskE=",
+        "lastModified": 1701137803,
+        "narHash": "sha256-0LcPAdql5IhQSUXJx3Zna0dYTgdIoYO7zUrsKgiBd04=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "d8efe70dc561c4bea0b7bf440d36ce98c497e054",
+        "rev": "9dd940c967502f844eacea52a61e9596268d4f70",
         "type": "github"
       },
       "original": {
@@ -118,6 +84,21 @@
         "repo": "rust-overlay",
         "type": "github"
       }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
     }
   },
   "root": "root",

flake.nix

@@ -4,30 +4,197 @@
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
     flake-utils.url = "github:numtide/flake-utils";
-    rust-overlay.url = "github:oxalica/rust-overlay";
-    naersk.url = "github:nmattia/naersk";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs = {
+        nixpkgs.follows = "nixpkgs";
+        flake-utils.follows = "flake-utils";
+      };
+    };
+    crane = {
+      url = "github:ipetkov/crane";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
-  outputs = inputs@{ self, nixpkgs, naersk, rust-overlay, flake-utils, ... }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; overlays = [ rust-overlay.overlay ]; };
-        rust = (pkgs.rustChannelOf {
-            date = "2021-05-01";
-            channel = "nightly";
-        }).minimal; # cargo, rustc and rust-std
-        naerskLib = naersk.lib."${system}".override {
-          # naersk can't build with stable?!
-          # inherit (pkgs.rust-bin.stable.latest) rustc cargo;
-          rustc = rust;
-          cargo = rust;
+  outputs = {
+    self,
+    nixpkgs,
+    crane,
+    flake-utils,
+    rust-overlay,
+    ...
+  }:
+    flake-utils.lib.eachDefaultSystem (system: let
+      pkgs = import nixpkgs {
+        inherit system;
+        overlays = [(import rust-overlay)];
+      };
+      mkRootPath = rel:
+        builtins.path {
+          path = "${toString ./.}/${rel}";
+          name = rel;
         };
-      in rec {
-        packages.helix = naerskLib.buildPackage {
-          pname = "helix";
-          root = ./.;
+      filteredSource = let
+        pathsToIgnore = [
+          ".envrc"
+          ".ignore"
+          ".github"
+          ".gitignore"
+          "logo_dark.svg"
+          "logo_light.svg"
+          "rust-toolchain.toml"
+          "rustfmt.toml"
+          "runtime"
+          "screenshot.png"
+          "book"
+          "docs"
+          "README.md"
+          "CHANGELOG.md"
+          "shell.nix"
+          "default.nix"
+          "grammars.nix"
+          "flake.nix"
+          "flake.lock"
+        ];
+        ignorePaths = path: type: let
+          inherit (nixpkgs) lib;
+          # split the nix store path into its components
+          components = lib.splitString "/" path;
+          # drop off the `/nix/hash-source` section from the path
+          relPathComponents = lib.drop 4 components;
+          # reassemble the path components
+          relPath = lib.concatStringsSep "/" relPathComponents;
+        in
+          lib.all (p: ! (lib.hasPrefix p relPath)) pathsToIgnore;
+      in
+        builtins.path {
+          name = "helix-source";
+          path = toString ./.;
+          # filter out unnecessary paths
+          filter = ignorePaths;
         };
-        defaultPackage = packages.helix;
-        devShell = pkgs.callPackage ./shell.nix {};
-      });
+      makeOverridableHelix = old: config: let
+        grammars = pkgs.callPackage ./grammars.nix config;
+        runtimeDir = pkgs.runCommand "helix-runtime" {} ''
+          mkdir -p $out
+          ln -s ${mkRootPath "runtime"}/* $out
+          rm -r $out/grammars
+          ln -s ${grammars} $out/grammars
+        '';
+        helix-wrapped =
+          pkgs.runCommand
+          old.name
+          {
+            inherit (old) pname version;
+            meta = old.meta or {};
+            passthru =
+              (old.passthru or {})
+              // {
+                unwrapped = old;
+              };
+            nativeBuildInputs = [pkgs.makeWrapper];
+            makeWrapperArgs = config.makeWrapperArgs or [];
+          }
+          ''
+            cp -rs --no-preserve=mode,ownership ${old} $out
+            wrapProgram "$out/bin/hx" ''${makeWrapperArgs[@]} --set HELIX_RUNTIME "${runtimeDir}"
+          '';
+      in
+        helix-wrapped
+        // {
+          override = makeOverridableHelix old;
+          passthru =
+            helix-wrapped.passthru
+            // {
+              wrapper = old: makeOverridableHelix old config;
+            };
+        };
+      stdenv =
+        if pkgs.stdenv.isLinux
+        then pkgs.stdenv
+        else pkgs.clangStdenv;
+      rustFlagsEnv =
+        if stdenv.isLinux
+        then ''$RUSTFLAGS -C link-arg=-fuse-ld=lld -C target-cpu=native -Clink-arg=-Wl,--no-rosegment''
+        else "$RUSTFLAGS";
+      rustToolchain = pkgs.pkgsBuildHost.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
+      craneLibMSRV = (crane.mkLib pkgs).overrideToolchain rustToolchain;
+      craneLibStable = (crane.mkLib pkgs).overrideToolchain pkgs.pkgsBuildHost.rust-bin.stable.latest.default;
+      commonArgs = {
+        inherit stdenv;
+        inherit (craneLibMSRV.crateNameFromCargoToml {cargoToml = ./helix-term/Cargo.toml;}) pname;
+        inherit (craneLibMSRV.crateNameFromCargoToml {cargoToml = ./Cargo.toml;}) version;
+        src = filteredSource;
+        # disable fetching and building of tree-sitter grammars in the helix-term build.rs
+        HELIX_DISABLE_AUTO_GRAMMAR_BUILD = "1";
+        buildInputs = [stdenv.cc.cc.lib];
+        # disable tests
+        doCheck = false;
+        meta.mainProgram = "hx";
+      };
+      cargoArtifacts = craneLibMSRV.buildDepsOnly commonArgs;
+    in {
+      packages = {
+        helix-unwrapped = craneLibStable.buildPackage (commonArgs
+          // {
+            cargoArtifacts = craneLibStable.buildDepsOnly commonArgs;
+            postInstall = ''
+              mkdir -p $out/share/applications $out/share/icons/hicolor/scalable/apps $out/share/icons/hicolor/256x256/apps
+              cp contrib/Helix.desktop $out/share/applications
+              cp logo.svg $out/share/icons/hicolor/scalable/apps/helix.svg
+              cp contrib/helix.png $out/share/icons/hicolor/256x256/apps
+            '';
+          });
+        helix = makeOverridableHelix self.packages.${system}.helix-unwrapped {};
+        default = self.packages.${system}.helix;
+      };
+
+      checks = {
+        # Build the crate itself
+        inherit (self.packages.${system}) helix;
+
+        clippy = craneLibMSRV.cargoClippy (commonArgs
+          // {
+            inherit cargoArtifacts;
+            cargoClippyExtraArgs = "--all-targets -- --deny warnings";
+          });
+
+        fmt = craneLibMSRV.cargoFmt commonArgs;
+
+        doc = craneLibMSRV.cargoDoc (commonArgs
+          // {
+            inherit cargoArtifacts;
+          });
+
+        test = craneLibMSRV.cargoTest (commonArgs
+          // {
+            inherit cargoArtifacts;
+          });
+      };
+
+      devShells.default = pkgs.mkShell {
+        inputsFrom = builtins.attrValues self.checks.${system};
+        nativeBuildInputs = with pkgs;
+          [lld_13 cargo-flamegraph rust-analyzer]
+          ++ (lib.optional (stdenv.isx86_64 && stdenv.isLinux) pkgs.cargo-tarpaulin)
+          ++ (lib.optional stdenv.isLinux pkgs.lldb)
+          ++ (lib.optional stdenv.isDarwin pkgs.darwin.apple_sdk.frameworks.CoreFoundation);
+        shellHook = ''
+          export HELIX_RUNTIME="$PWD/runtime"
+          export RUST_BACKTRACE="1"
+          export RUSTFLAGS="${rustFlagsEnv}"
+        '';
+      };
+    })
+    // {
+      overlays.default = final: prev: {
+        inherit (self.packages.${final.system}) helix;
+      };
+    };
+
+  nixConfig = {
+    extra-substituters = ["https://helix.cachix.org"];
+    extra-trusted-public-keys = ["helix.cachix.org-1:ejp9KQpR1FBI2onstMQ34yogDm4OgU2ru6lIwPvuCVs="];
+  };
 }

grammars.nix

@@ -0,0 +1,124 @@
+{
+  stdenv,
+  lib,
+  runCommandLocal,
+  runCommand,
+  yj,
+  includeGrammarIf ? _: true,
+  grammarOverlays ? [],
+  ...
+}: let
+  # HACK: nix < 2.6 has a bug in the toml parser, so we convert to JSON
+  # before parsing
+  languages-json = runCommandLocal "languages-toml-to-json" {} ''
+    ${yj}/bin/yj -t < ${./languages.toml} > $out
+  '';
+  languagesConfig =
+    if lib.versionAtLeast builtins.nixVersion "2.6.0"
+    then builtins.fromTOML (builtins.readFile ./languages.toml)
+    else builtins.fromJSON (builtins.readFile (builtins.toPath languages-json));
+  isGitGrammar = grammar:
+    builtins.hasAttr "source" grammar
+    && builtins.hasAttr "git" grammar.source
+    && builtins.hasAttr "rev" grammar.source;
+  isGitHubGrammar = grammar: lib.hasPrefix "https://github.com" grammar.source.git;
+  toGitHubFetcher = url: let
+    match = builtins.match "https://github\.com/([^/]*)/([^/]*)/?" url;
+  in {
+    owner = builtins.elemAt match 0;
+    repo = builtins.elemAt match 1;
+  };
+  gitGrammars = builtins.filter isGitGrammar languagesConfig.grammar;
+  buildGrammar = grammar: let
+    gh = toGitHubFetcher grammar.source.git;
+    sourceGit = builtins.fetchTree {
+      type = "git";
+      url = grammar.source.git;
+      rev = grammar.source.rev;
+      ref = grammar.source.ref or "HEAD";
+      shallow = true;
+    };
+    sourceGitHub = builtins.fetchTree {
+      type = "github";
+      owner = gh.owner;
+      repo = gh.repo;
+      inherit (grammar.source) rev;
+    };
+    source =
+      if isGitHubGrammar grammar
+      then sourceGitHub
+      else sourceGit;
+  in
+    stdenv.mkDerivation {
+      # see https://github.com/NixOS/nixpkgs/blob/fbdd1a7c0bc29af5325e0d7dd70e804a972eb465/pkgs/development/tools/parsing/tree-sitter/grammar.nix
+
+      pname = "helix-tree-sitter-${grammar.name}";
+      version = grammar.source.rev;
+
+      src = source;
+      sourceRoot = if builtins.hasAttr "subpath" grammar.source then
+        "source/${grammar.source.subpath}"
+      else
+        "source";
+
+      dontConfigure = true;
+
+      FLAGS = [
+        "-Isrc"
+        "-g"
+        "-O3"
+        "-fPIC"
+        "-fno-exceptions"
+        "-Wl,-z,relro,-z,now"
+      ];
+
+      NAME = grammar.name;
+
+      buildPhase = ''
+        runHook preBuild
+
+        if [[ -e src/scanner.cc ]]; then
+          $CXX -c src/scanner.cc -o scanner.o $FLAGS
+        elif [[ -e src/scanner.c ]]; then
+          $CC -c src/scanner.c -o scanner.o $FLAGS
+        fi
+
+        $CC -c src/parser.c -o parser.o $FLAGS
+        $CXX -shared -o $NAME.so *.o
+
+        ls -al
+
+        runHook postBuild
+      '';
+
+      installPhase = ''
+        runHook preInstall
+        mkdir $out
+        mv $NAME.so $out/
+        runHook postInstall
+      '';
+
+      # Strip failed on darwin: strip: error: symbols referenced by indirect symbol table entries that can't be stripped
+      fixupPhase = lib.optionalString stdenv.isLinux ''
+        runHook preFixup
+        $STRIP $out/$NAME.so
+        runHook postFixup
+      '';
+    };
+  grammarsToBuild = builtins.filter includeGrammarIf gitGrammars;
+  builtGrammars = builtins.map (grammar: {
+    inherit (grammar) name;
+    value = buildGrammar grammar;
+  }) grammarsToBuild;
+  extensibleGrammars =
+    lib.makeExtensible (self: builtins.listToAttrs builtGrammars);
+  overlayedGrammars = lib.pipe extensibleGrammars
+    (builtins.map (overlay: grammar: grammar.extend overlay) grammarOverlays);
+  grammarLinks = lib.mapAttrsToList
+    (name: artifact: "ln -s ${artifact}/${name}.so $out/${name}.so")
+    (lib.filterAttrs (n: v: lib.isDerivation v) overlayedGrammars);
+in
+  runCommand "consolidated-helix-grammars" {} ''
+    mkdir -p $out
+    ${builtins.concatStringsSep "\n" grammarLinks}
+  ''

helix-core/Cargo.toml

@@ -1,26 +1,57 @@
 [package]
 name = "helix-core"
-version = "0.1.0"
-authors = ["Blaž Hrastnik <blaz@mxxn.io>"]
-edition = "2018"
-license = "MPL-2.0"
+description = "Helix editor core editing primitives"
+include = ["src/**/*", "README.md"]
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+rust-version.workspace = true
+categories.workspace = true
+repository.workspace = true
+homepage.workspace = true
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[features]
+unicode-lines = ["ropey/unicode_lines"]
+integration = []
 
 [dependencies]
-helix-syntax = { path = "../helix-syntax" }
+helix-loader = { path = "../helix-loader" }
 
-ropey = "1.2"
-anyhow = "1"
-smallvec = "1.4"
-tendril = "0.4.2"
-unicode-segmentation = "1.6"
+ropey = { version = "1.6.1", default-features = false, features = ["simd"] }
+smallvec = "1.11"
+smartstring = "1.0.1"
+unicode-segmentation = "1.10"
 unicode-width = "0.1"
+unicode-general-category = "0.6"
 # slab = "0.4.2"
-tree-sitter = "0.19"
-once_cell = "1.4"
+slotmap = "1.0"
+tree-sitter.workspace = true
+once_cell = "1.19"
+arc-swap = "1"
 regex = "1"
+bitflags = "2.4"
+ahash = "0.8.6"
+hashbrown = { version = "0.14.3", features = ["raw"] }
+dunce = "1.0"
 
+log = "0.4"
 serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+toml = "0.7"
 
-etcetera = "0.3"
+imara-diff = "0.1.0"
+
+encoding_rs = "0.8"
+
+chrono = { version = "0.4", default-features = false, features = ["alloc", "std"] }
+
+etcetera = "0.8"
+textwrap = "0.16.0"
+
+nucleo.workspace = true
+parking_lot = "0.12"
+
+[dev-dependencies]
+quickcheck = { version = "1", default-features = false }
+indoc = "2.0.4"

helix-core/src/auto_pairs.rs

@@ -1,9 +1,13 @@
-use crate::{Range, Rope, Selection, Tendril, Transaction};
+//! When typing the opening character of one of the possible pairs defined below,
+//! this module provides the functionality to insert the paired closing character.
+
+use crate::{graphemes, movement::Direction, Range, Rope, Selection, Tendril, Transaction};
+use std::collections::HashMap;
+
 use smallvec::SmallVec;
 
 // Heavily based on https://github.com/codemirror/closebrackets/
-
-pub const PAIRS: &[(char, char)] = &[
+pub const DEFAULT_PAIRS: &[(char, char)] = &[
     ('(', ')'),
     ('{', '}'),
     ('[', ']'),
@@ -12,7 +16,95 @@ pub const PAIRS: &[(char, char)] = &[
     ('`', '`'),
 ];
 
-const CLOSE_BEFORE: &str = ")]}'\":;> \n"; // includes space and newline
+/// The type that represents the collection of auto pairs,
+/// keyed by both opener and closer.
+#[derive(Debug, Clone)]
+pub struct AutoPairs(HashMap<char, Pair>);
+
+/// Represents the config for a particular pairing.
+#[derive(Debug, Clone, Copy)]
+pub struct Pair {
+    pub open: char,
+    pub close: char,
+}
+
+impl Pair {
+    /// true if open == close
+    pub fn same(&self) -> bool {
+        self.open == self.close
+    }
+
+    /// true if all of the pair's conditions hold for the given document and range
+    pub fn should_close(&self, doc: &Rope, range: &Range) -> bool {
+        let mut should_close = Self::next_is_not_alpha(doc, range);
+
+        if self.same() {
+            should_close &= Self::prev_is_not_alpha(doc, range);
+        }
+
+        should_close
+    }
+
+    pub fn next_is_not_alpha(doc: &Rope, range: &Range) -> bool {
+        let cursor = range.cursor(doc.slice(..));
+        let next_char = doc.get_char(cursor);
+        next_char.map(|c| !c.is_alphanumeric()).unwrap_or(true)
+    }
+
+    pub fn prev_is_not_alpha(doc: &Rope, range: &Range) -> bool {
+        let cursor = range.cursor(doc.slice(..));
+        let prev_char = prev_char(doc, cursor);
+        prev_char.map(|c| !c.is_alphanumeric()).unwrap_or(true)
+    }
+}
+
+impl From<&(char, char)> for Pair {
+    fn from(&(open, close): &(char, char)) -> Self {
+        Self { open, close }
+    }
+}
+
+impl From<(&char, &char)> for Pair {
+    fn from((open, close): (&char, &char)) -> Self {
+        Self {
+            open: *open,
+            close: *close,
+        }
+    }
+}
+
+impl AutoPairs {
+    /// Make a new AutoPairs set with the given pairs and default conditions.
+    pub fn new<'a, V: 'a, A>(pairs: V) -> Self
+    where
+        V: IntoIterator<Item = A>,
+        A: Into<Pair>,
+    {
+        let mut auto_pairs = HashMap::new();
+
+        for pair in pairs.into_iter() {
+            let auto_pair = pair.into();
+
+            auto_pairs.insert(auto_pair.open, auto_pair);
+
+            if auto_pair.open != auto_pair.close {
+                auto_pairs.insert(auto_pair.close, auto_pair);
+            }
+        }
+
+        Self(auto_pairs)
+    }
+
+    pub fn get(&self, ch: char) -> Option<&Pair> {
+        self.0.get(&ch)
+    }
+}
+
+impl Default for AutoPairs {
+    fn default() -> Self {
+        AutoPairs::new(DEFAULT_PAIRS.iter())
+    }
+}
 
 // insert hook:
 // Fn(doc, selection, char) => Option<Transaction>
@@ -22,122 +114,260 @@ const CLOSE_BEFORE: &str = ")]}'\":;> \n"; // includes space and newline
 //
 // to simplify, maybe return Option<Transaction> and just reimplement the default
 
-// TODO: delete implementation where it erases the whole bracket (|) -> |
+// [TODO]
+// * delete implementation where it erases the whole bracket (|) -> |
+// * change to multi character pairs to handle cases like placing the cursor in the
+//   middle of triple quotes, and more exotic pairs like Jinja's {% %}
 
 #[must_use]
-pub fn hook(doc: &Rope, selection: &Selection, ch: char) -> Option<Transaction> {
-    for &(open, close) in PAIRS {
-        if open == ch {
-            if open == close {
-                return handle_same(doc, selection, open);
-            } else {
-                return Some(handle_open(doc, selection, open, close, CLOSE_BEFORE));
-            }
-        }
+pub fn hook(doc: &Rope, selection: &Selection, ch: char, pairs: &AutoPairs) -> Option<Transaction> {
+    log::trace!("autopairs hook selection: {:#?}", selection);
 
-        if close == ch {
+    if let Some(pair) = pairs.get(ch) {
+        if pair.same() {
+            return Some(handle_same(doc, selection, pair));
+        } else if pair.open == ch {
+            return Some(handle_open(doc, selection, pair));
+        } else if pair.close == ch {
             // && char_at pos == close
-            return Some(handle_close(doc, selection, open, close));
+            return Some(handle_close(doc, selection, pair));
         }
     }
 
     None
 }
 
-// TODO: special handling for lifetimes in rust: if preceeded by & or < don't auto close '
-// for example "&'a mut", or "fn<'a>"
-
-fn next_char(doc: &Rope, pos: usize) -> Option<char> {
-    if pos >= doc.len_chars() {
+fn prev_char(doc: &Rope, pos: usize) -> Option<char> {
+    if pos == 0 {
         return None;
     }
-    Some(doc.char(pos))
+
+    doc.get_char(pos - 1)
 }
-// TODO: selections should be extended if range, moved if point.
 
-// TODO: if not cursor but selection, wrap on both sides of selection (surround)
-fn handle_open(
-    doc: &Rope,
-    selection: &Selection,
-    open: char,
-    close: char,
-    close_before: &str,
-) -> Transaction {
-    let mut ranges = SmallVec::with_capacity(selection.len());
+/// calculate what the resulting range should be for an auto pair insertion
+fn get_next_range(doc: &Rope, start_range: &Range, offset: usize, len_inserted: usize) -> Range {
+    // When the character under the cursor changes due to complete pair
+    // insertion, we must look backward a grapheme and then add the length
+    // of the insertion to put the resulting cursor in the right place, e.g.
+    //
+    // foo[\r\n] - anchor: 3, head: 5
+    // foo([)]\r\n - anchor: 4, head: 5
+    //
+    // foo[\r\n] - anchor: 3, head: 5
+    // foo'[\r\n] - anchor: 4, head: 6
+    //
+    // foo([)]\r\n - anchor: 4, head: 5
+    // foo()[\r\n] - anchor: 5, head: 7
+    //
+    // [foo]\r\n - anchor: 0, head: 3
+    // [foo(])\r\n - anchor: 0, head: 5
 
-    let mut transaction = Transaction::change_by_selection(doc, selection, |range| {
-        let pos = range.head;
-        let next = next_char(doc, pos);
+    // inserting at the very end of the document after the last newline
+    if start_range.head == doc.len_chars() && start_range.anchor == doc.len_chars() {
+        return Range::new(
+            start_range.anchor + offset + 1,
+            start_range.head + offset + 1,
+        );
+    }
 
-        let head = pos + open.len_utf8();
-        // if selection, retain anchor, if cursor, move over
-        ranges.push(Range::new(
-            if range.is_empty() { head } else { range.anchor },
-            head,
-        ));
+    let doc_slice = doc.slice(..);
+    let single_grapheme = start_range.is_single_grapheme(doc_slice);
 
-        match next {
-            Some(ch) if !close_before.contains(ch) => {
-                // TODO: else return (use default handler that inserts open)
-                (pos, pos, Some(Tendril::from_char(open)))
+    // just skip over graphemes
+    if len_inserted == 0 {
+        let end_anchor = if single_grapheme {
+            graphemes::next_grapheme_boundary(doc_slice, start_range.anchor) + offset
+
+        // even for backward inserts with multiple grapheme selections,
+        // we want the anchor to stay where it is so that the relative
+        // selection does not change, e.g.:
+        //
+        // foo([) wor]d -> insert ) -> foo()[ wor]d
+        } else {
+            start_range.anchor + offset
+        };
+
+        return Range::new(
+            end_anchor,
+            graphemes::next_grapheme_boundary(doc_slice, start_range.head) + offset,
+        );
+    }
+
+    // trivial case: only inserted a single-char opener, just move the selection
+    if len_inserted == 1 {
+        let end_anchor = if single_grapheme || start_range.direction() == Direction::Backward {
+            start_range.anchor + offset + 1
+        } else {
+            start_range.anchor + offset
+        };
+
+        return Range::new(end_anchor, start_range.head + offset + 1);
+    }
+
+    // If the head = 0, then we must be in insert mode with a backward
+    // cursor, which implies the head will just move
+    let end_head = if start_range.head == 0 || start_range.direction() == Direction::Backward {
+        start_range.head + offset + 1
+    } else {
+        // We must have a forward cursor, which means we must move to the
+        // other end of the grapheme to get to where the new characters
+        // are inserted, then move the head to where it should be
+        let prev_bound = graphemes::prev_grapheme_boundary(doc_slice, start_range.head);
+        log::trace!(
+            "prev_bound: {}, offset: {}, len_inserted: {}",
+            prev_bound,
+            offset,
+            len_inserted
+        );
+        prev_bound + offset + len_inserted
+    };
+
+    let end_anchor = match (start_range.len(), start_range.direction()) {
+        // if we have a zero width cursor, it shifts to the same number
+        (0, _) => end_head,
+
+        // If we are inserting for a regular one-width cursor, the anchor
+        // moves with the head. This is the fast path for ASCII.
+        (1, Direction::Forward) => end_head - 1,
+        (1, Direction::Backward) => end_head + 1,
+
+        (_, Direction::Forward) => {
+            if single_grapheme {
+                graphemes::prev_grapheme_boundary(doc.slice(..), start_range.head) + 1
+
+            // if we are appending, the anchor stays where it is; only offset
+            // for multiple range insertions
+            } else {
+                start_range.anchor + offset
+            }
+        }
+
+        (_, Direction::Backward) => {
+            if single_grapheme {
+                // if we're backward, then the head is at the first char
+                // of the typed char, so we need to add the length of
+                // the closing char
+                graphemes::prev_grapheme_boundary(doc.slice(..), start_range.anchor)
+                    + len_inserted
+                    + offset
+            } else {
+                // when we are inserting in front of a selection, we need to move
+                // the anchor over by however many characters were inserted overall
+                start_range.anchor + offset + len_inserted
+            }
+        }
+    };
+
+    Range::new(end_anchor, end_head)
+}
+
+fn handle_open(doc: &Rope, selection: &Selection, pair: &Pair) -> Transaction {
+    let mut end_ranges = SmallVec::with_capacity(selection.len());
+    let mut offs = 0;
+
+    let transaction = Transaction::change_by_selection(doc, selection, |start_range| {
+        let cursor = start_range.cursor(doc.slice(..));
+        let next_char = doc.get_char(cursor);
+        let len_inserted;
+
+        // Since auto pairs are currently limited to single chars, we're either
+        // inserting exactly one or two chars. When arbitrary length pairs are
+        // added, these will need to be changed.
+        let change = match next_char {
+            Some(_) if !pair.should_close(doc, start_range) => {
+                len_inserted = 1;
+                let mut tendril = Tendril::new();
+                tendril.push(pair.open);
+                (cursor, cursor, Some(tendril))
             }
-            // None | Some(ch) if close_before.contains(ch) => {}
             _ => {
                 // insert open & close
-                let mut pair = Tendril::with_capacity(2);
-                pair.push_char(open);
-                pair.push_char(close);
-
-                (pos, pos, Some(pair))
+                let pair_str = Tendril::from_iter([pair.open, pair.close]);
+                len_inserted = 2;
+                (cursor, cursor, Some(pair_str))
             }
-        }
+        };
+
+        let next_range = get_next_range(doc, start_range, offs, len_inserted);
+        end_ranges.push(next_range);
+        offs += len_inserted;
+
+        change
     });
 
-    transaction.with_selection(Selection::new(ranges, selection.primary_index()))
+    let t = transaction.with_selection(Selection::new(end_ranges, selection.primary_index()));
+    log::debug!("auto pair transaction: {:#?}", t);
+    t
 }
 
-fn handle_close(doc: &Rope, selection: &Selection, _open: char, close: char) -> Transaction {
-    let mut ranges = SmallVec::with_capacity(selection.len());
+fn handle_close(doc: &Rope, selection: &Selection, pair: &Pair) -> Transaction {
+    let mut end_ranges = SmallVec::with_capacity(selection.len());
+    let mut offs = 0;
 
-    let mut transaction = Transaction::change_by_selection(doc, selection, |range| {
-        let pos = range.head;
-        let next = next_char(doc, pos);
+    let transaction = Transaction::change_by_selection(doc, selection, |start_range| {
+        let cursor = start_range.cursor(doc.slice(..));
+        let next_char = doc.get_char(cursor);
+        let mut len_inserted = 0;
 
-        let head = pos + close.len_utf8();
-        // if selection, retain anchor, if cursor, move over
-        ranges.push(Range::new(
-            if range.is_empty() { head } else { range.anchor },
-            head,
-        ));
-
-        if next == Some(close) {
-            //  return transaction that moves past close
-            (pos, pos, None) // no-op
+        let change = if next_char == Some(pair.close) {
+            // return transaction that moves past close
+            (cursor, cursor, None) // no-op
         } else {
-            // TODO: else return (use default handler that inserts close)
-            (pos, pos, Some(Tendril::from_char(close)))
-        }
+            len_inserted = 1;
+            let mut tendril = Tendril::new();
+            tendril.push(pair.close);
+            (cursor, cursor, Some(tendril))
+        };
+
+        let next_range = get_next_range(doc, start_range, offs, len_inserted);
+        end_ranges.push(next_range);
+        offs += len_inserted;
+
+        change
     });
 
-    transaction.with_selection(Selection::new(ranges, selection.primary_index()))
+    let t = transaction.with_selection(Selection::new(end_ranges, selection.primary_index()));
+    log::debug!("auto pair transaction: {:#?}", t);
+    t
 }
 
-// handle cases where open and close is the same, or in triples ("""docstring""")
-fn handle_same(doc: &Rope, selection: &Selection, token: char) -> Option<Transaction> {
-    // if not cursor but selection, wrap
-    // let next = next char
+/// handle cases where open and close is the same, or in triples ("""docstring""")
+fn handle_same(doc: &Rope, selection: &Selection, pair: &Pair) -> Transaction {
+    let mut end_ranges = SmallVec::with_capacity(selection.len());
 
-    // if next == bracket {
-    //   // if start of syntax node, insert token twice (new pair because node is complete)
-    //   // elseif colsedBracketAt
-    //      // is_triple == allow triple && next 3 is equal
-    //      // cursor jump over
-    // }
-    //} else if allow_triple && followed by triple {
-    //}
-    //} else if next != word char && prev != bracket && prev != word char {
-    // // condition checks for cases like I' where you don't want I'' (or I'm)
-    //  insert pair ("")
-    //}
-    None
+    let mut offs = 0;
+
+    let transaction = Transaction::change_by_selection(doc, selection, |start_range| {
+        let cursor = start_range.cursor(doc.slice(..));
+        let mut len_inserted = 0;
+        let next_char = doc.get_char(cursor);
+
+        let change = if next_char == Some(pair.open) {
+            //  return transaction that moves past close
+            (cursor, cursor, None) // no-op
+        } else {
+            let mut pair_str = Tendril::new();
+            pair_str.push(pair.open);
+
+            // for equal pairs, don't insert both open and close if either
+            // side has a non-pair char
+            if pair.should_close(doc, start_range) {
+                pair_str.push(pair.close);
+            }
+
+            len_inserted += pair_str.chars().count();
+            (cursor, cursor, Some(pair_str))
+        };
+
+        let next_range = get_next_range(doc, start_range, offs, len_inserted);
+        end_ranges.push(next_range);
+        offs += len_inserted;
+
+        change
+    });
+
+    let t = transaction.with_selection(Selection::new(end_ranges, selection.primary_index()));
+    log::debug!("auto pair transaction: {:#?}", t);
+    t
 }

helix-core/src/chars.rs

@@ -0,0 +1,137 @@
+//! Utility functions to categorize a `char`.
+
+use crate::LineEnding;
+
+#[derive(Debug, Eq, PartialEq)]
+pub enum CharCategory {
+    Whitespace,
+    Eol,
+    Word,
+    Punctuation,
+    Unknown,
+}
+
+#[inline]
+pub fn categorize_char(ch: char) -> CharCategory {
+    if char_is_line_ending(ch) {
+        CharCategory::Eol
+    } else if ch.is_whitespace() {
+        CharCategory::Whitespace
+    } else if char_is_word(ch) {
+        CharCategory::Word
+    } else if char_is_punctuation(ch) {
+        CharCategory::Punctuation
+    } else {
+        CharCategory::Unknown
+    }
+}
+
+/// Determine whether a character is a line ending.
+#[inline]
+pub fn char_is_line_ending(ch: char) -> bool {
+    LineEnding::from_char(ch).is_some()
+}
+
+/// Determine whether a character qualifies as (non-line-break)
+/// whitespace.
+#[inline]
+pub fn char_is_whitespace(ch: char) -> bool {
+    // TODO: this is a naive binary categorization of whitespace
+    // characters.  For display, word wrapping, etc. we'll need a better
+    // categorization based on e.g. breaking vs non-breaking spaces
+    // and whether they're zero-width or not.
+    match ch {
+        //'\u{1680}' | // Ogham Space Mark (here for completeness, but usually displayed as a dash, not as whitespace)
+        '\u{0009}' | // Character Tabulation
+        '\u{0020}' | // Space
+        '\u{00A0}' | // No-break Space
+        '\u{180E}' | // Mongolian Vowel Separator
+        '\u{202F}' | // Narrow No-break Space
+        '\u{205F}' | // Medium Mathematical Space
+        '\u{3000}' | // Ideographic Space
+        '\u{FEFF}'   // Zero Width No-break Space
+        => true,
+
+        // En Quad, Em Quad, En Space, Em Space, Three-per-em Space,
+        // Four-per-em Space, Six-per-em Space, Figure Space,
+        // Punctuation Space, Thin Space, Hair Space, Zero Width Space.
+        ch if ('\u{2000}' ..= '\u{200B}').contains(&ch) => true,
+
+        _ => false,
+    }
+}
+
+#[inline]
+pub fn char_is_punctuation(ch: char) -> bool {
+    use unicode_general_category::{get_general_category, GeneralCategory};
+
+    matches!(
+        get_general_category(ch),
+        GeneralCategory::OtherPunctuation
+            | GeneralCategory::OpenPunctuation
+            | GeneralCategory::ClosePunctuation
+            | GeneralCategory::InitialPunctuation
+            | GeneralCategory::FinalPunctuation
+            | GeneralCategory::ConnectorPunctuation
+            | GeneralCategory::DashPunctuation
+            | GeneralCategory::MathSymbol
+            | GeneralCategory::CurrencySymbol
+            | GeneralCategory::ModifierSymbol
+    )
+}
+
+#[inline]
+pub fn char_is_word(ch: char) -> bool {
+    ch.is_alphanumeric() || ch == '_'
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_categorize() {
+        #[cfg(not(feature = "unicode-lines"))]
+        const EOL_TEST_CASE: &str = "\n";
+        #[cfg(feature = "unicode-lines")]
+        const EOL_TEST_CASE: &str = "\n\u{000B}\u{000C}\u{0085}\u{2028}\u{2029}";
+        const WORD_TEST_CASE: &str = "_hello_world_あいうえおー1234567890１２３４５６７８９０";
+        const PUNCTUATION_TEST_CASE: &str =
+            "!\"#$%&\'()*+,-./:;<=>?@[\\]^`{|}~！”＃＄％＆’（）＊＋、。：；＜＝＞？＠「」＾｀｛｜｝～";
+        const WHITESPACE_TEST_CASE: &str = "  　   ";
+
+        for ch in EOL_TEST_CASE.chars() {
+            assert_eq!(CharCategory::Eol, categorize_char(ch));
+        }
+
+        for ch in WHITESPACE_TEST_CASE.chars() {
+            assert_eq!(
+                CharCategory::Whitespace,
+                categorize_char(ch),
+                "Testing '{}', but got `{:?}` instead of `Category::Whitespace`",
+                ch,
+                categorize_char(ch)
+            );
+        }
+
+        for ch in WORD_TEST_CASE.chars() {
+            assert_eq!(
+                CharCategory::Word,
+                categorize_char(ch),
+                "Testing '{}', but got `{:?}` instead of `Category::Word`",
+                ch,
+                categorize_char(ch)
+            );
+        }
+
+        for ch in PUNCTUATION_TEST_CASE.chars() {
+            assert_eq!(
+                CharCategory::Punctuation,
+                categorize_char(ch),
+                "Testing '{}', but got `{:?}` instead of `Category::Punctuation`",
+                ch,
+                categorize_char(ch)
+            );
+        }
+    }
+}

helix-core/src/comment.rs

@@ -1,20 +1,33 @@
+//! This module contains the functionality toggle comments on lines over the selection
+//! using the comment character defined in the user's `languages.toml`
+
 use crate::{
-    find_first_non_whitespace_char2, Change, Rope, RopeSlice, Selection, Tendril, Transaction,
+    find_first_non_whitespace_char, Change, Rope, RopeSlice, Selection, Tendril, Transaction,
 };
-use core::ops::Range;
 use std::borrow::Cow;
 
+/// Given text, a comment token, and a set of line indices, returns the following:
+/// - Whether the given lines should be considered commented
+///     - If any of the lines are uncommented, all lines are considered as such.
+/// - The lines to change for toggling comments
+///     - This is all provided lines excluding blanks lines.
+/// - The column of the comment tokens
+///     - Column of existing tokens, if the lines are commented; column to place tokens at otherwise.
+/// - The margin to the right of the comment tokens
+///     - Defaults to `1`. If any existing comment token is not followed by a space, changes to `0`.
 fn find_line_comment(
     token: &str,
     text: RopeSlice,
-    lines: Range<usize>,
-) -> (bool, Vec<usize>, usize) {
+    lines: impl IntoIterator<Item = usize>,
+) -> (bool, Vec<usize>, usize, usize) {
     let mut commented = true;
-    let mut skipped = Vec::new();
+    let mut to_change = Vec::new();
     let mut min = usize::MAX; // minimum col for find_first_non_whitespace_char
+    let mut margin = 1;
+    let token_len = token.chars().count();
     for line in lines {
         let line_slice = text.line(line);
-        if let Some(pos) = find_first_non_whitespace_char2(line_slice) {
+        if let Some(pos) = find_first_non_whitespace_char(line_slice) {
             let len = line_slice.len_chars();
 
             if pos < min {
@@ -29,47 +42,55 @@ fn find_line_comment(
                 // considered uncommented.
                 commented = false;
             }
-        } else {
-            // blank line
-            skipped.push(line);
+
+            // determine margin of 0 or 1 for uncommenting; if any comment token is not followed by a space,
+            // a margin of 0 is used for all lines.
+            if !matches!(line_slice.get_char(pos + token_len), Some(c) if c == ' ') {
+                margin = 0;
+            }
+
+            // blank lines don't get pushed.
+            to_change.push(line);
         }
     }
-    (commented, skipped, min)
+    (commented, to_change, min, margin)
 }
 
 #[must_use]
-pub fn toggle_line_comments(doc: &Rope, selection: &Selection) -> Transaction {
+pub fn toggle_line_comments(doc: &Rope, selection: &Selection, token: Option<&str>) -> Transaction {
     let text = doc.slice(..);
-    let mut changes: Vec<Change> = Vec::new();
 
-    let token = "//";
+    let token = token.unwrap_or("//");
     let comment = Tendril::from(format!("{} ", token));
 
+    let mut lines: Vec<usize> = Vec::with_capacity(selection.len());
+
+    let mut min_next_line = 0;
     for selection in selection {
-        let start = text.char_to_line(selection.from());
-        let end = text.char_to_line(selection.to());
-        let lines = start..end + 1;
-        let (commented, skipped, min) = find_line_comment(token, text, lines.clone());
+        let (start, end) = selection.line_range(text);
+        let start = start.clamp(min_next_line, text.len_lines());
+        let end = (end + 1).min(text.len_lines());
 
-        changes.reserve(end - start - skipped.len());
+        lines.extend(start..end);
+        min_next_line = end;
+    }
 
-        for line in lines {
-            if skipped.contains(&line) {
-                continue;
-            }
+    let (commented, to_change, min, margin) = find_line_comment(token, text, lines);
 
-            let pos = text.line_to_char(line) + min;
+    let mut changes: Vec<Change> = Vec::with_capacity(to_change.len());
 
-            if !commented {
-                // comment line
-                changes.push((pos, pos, Some(comment.clone())))
-            } else {
-                // uncomment line
-                let margin = 1; // TODO: margin is hardcoded 1 but could easily be 0
-                changes.push((pos, pos + token.len() + margin, None))
-            }
+    for line in to_change {
+        let pos = text.line_to_char(line) + min;
+
+        if !commented {
+            // comment line
+            changes.push((pos, pos, Some(comment.clone())));
+        } else {
+            // uncomment line
+            changes.push((pos, pos + token.len() + margin, None));
         }
     }
+
     Transaction::change(doc, changes.into_iter())
 }
 
@@ -79,35 +100,53 @@ mod test {
 
     #[test]
     fn test_find_line_comment() {
-        use crate::State;
-
         // four lines, two space indented, except for line 1 which is blank.
-        let doc = Rope::from("  1\n\n  2\n  3");
-
-        let mut state = State::new(doc);
+        let mut doc = Rope::from("  1\n\n  2\n  3");
         // select whole document
-        state.selection = Selection::single(0, state.doc.len_chars() - 1);
+        let mut selection = Selection::single(0, doc.len_chars() - 1);
 
-        let text = state.doc.slice(..);
+        let text = doc.slice(..);
 
         let res = find_line_comment("//", text, 0..3);
-        // (commented = true, skipped = [line 1], min = col 2)
-        assert_eq!(res, (false, vec![1], 2));
+        // (commented = true, to_change = [line 0, line 2], min = col 2, margin = 0)
+        assert_eq!(res, (false, vec![0, 2], 2, 0));
 
         // comment
-        let transaction = toggle_line_comments(&state.doc, &state.selection);
-        transaction.apply(&mut state.doc);
-        state.selection = state.selection.clone().map(transaction.changes());
+        let transaction = toggle_line_comments(&doc, &selection, None);
+        transaction.apply(&mut doc);
+        selection = selection.map(transaction.changes());
 
-        assert_eq!(state.doc, "  // 1\n\n  // 2\n  // 3");
+        assert_eq!(doc, "  // 1\n\n  // 2\n  // 3");
 
         // uncomment
-        let transaction = toggle_line_comments(&state.doc, &state.selection);
-        transaction.apply(&mut state.doc);
-        state.selection = state.selection.clone().map(transaction.changes());
-        assert_eq!(state.doc, "  1\n\n  2\n  3");
+        let transaction = toggle_line_comments(&doc, &selection, None);
+        transaction.apply(&mut doc);
+        selection = selection.map(transaction.changes());
+        assert_eq!(doc, "  1\n\n  2\n  3");
+        assert!(selection.len() == 1); // to ignore the selection unused warning
+
+        // 0 margin comments
+        doc = Rope::from("  //1\n\n  //2\n  //3");
+        // reset the selection.
+        selection = Selection::single(0, doc.len_chars() - 1);
+
+        let transaction = toggle_line_comments(&doc, &selection, None);
+        transaction.apply(&mut doc);
+        selection = selection.map(transaction.changes());
+        assert_eq!(doc, "  1\n\n  2\n  3");
+        assert!(selection.len() == 1); // to ignore the selection unused warning
+
+        // 0 margin comments, with no space
+        doc = Rope::from("//");
+        // reset the selection.
+        selection = Selection::single(0, doc.len_chars() - 1);
+
+        let transaction = toggle_line_comments(&doc, &selection, None);
+        transaction.apply(&mut doc);
+        selection = selection.map(transaction.changes());
+        assert_eq!(doc, "");
+        assert!(selection.len() == 1); // to ignore the selection unused warning
 
-        // TODO: account for no margin after comment
         // TODO: account for uncommenting with uneven comment indentation
     }
 }

helix-core/src/config.rs

@@ -0,0 +1,10 @@
+/// Syntax configuration loader based on built-in languages.toml.
+pub fn default_syntax_loader() -> crate::syntax::Configuration {
+    helix_loader::config::default_lang_config()
+        .try_into()
+        .expect("Could not serialize built-in languages.toml")
+}
+/// Syntax configuration loader based on user configured languages.toml.
+pub fn user_syntax_loader() -> Result<crate::syntax::Configuration, toml::de::Error> {
+    helix_loader::config::user_lang_config()?.try_into()
+}

helix-core/src/diagnostic.rs

@@ -1,18 +1,54 @@
-#[derive(Eq, PartialEq)]
+//! LSP diagnostic utility types.
+use serde::{Deserialize, Serialize};
+
+/// Describes the severity level of a [`Diagnostic`].
+#[derive(Debug, Clone, Copy, Eq, PartialEq, PartialOrd, Ord, Deserialize, Serialize)]
 pub enum Severity {
-    Error,
-    Warning,
-    Info,
     Hint,
+    Info,
+    Warning,
+    Error,
 }
 
+impl Default for Severity {
+    fn default() -> Self {
+        Self::Hint
+    }
+}
+
+/// A range of `char`s within the text.
+#[derive(Debug, Clone, Copy, PartialOrd, Ord, PartialEq, Eq)]
 pub struct Range {
     pub start: usize,
     pub end: usize,
 }
+
+#[derive(Debug, Eq, Hash, PartialEq, Clone, Deserialize, Serialize)]
+pub enum NumberOrString {
+    Number(i32),
+    String(String),
+}
+
+#[derive(Debug, Clone)]
+pub enum DiagnosticTag {
+    Unnecessary,
+    Deprecated,
+}
+
+/// Corresponds to [`lsp_types::Diagnostic`](https://docs.rs/lsp-types/0.94.0/lsp_types/struct.Diagnostic.html)
+#[derive(Debug, Clone)]
 pub struct Diagnostic {
     pub range: Range,
+    // whether this diagnostic ends at the end of(or inside) a word
+    pub ends_at_word: bool,
+    pub starts_at_word: bool,
+    pub zero_width: bool,
     pub line: usize,
     pub message: String,
     pub severity: Option<Severity>,
+    pub code: Option<NumberOrString>,
+    pub language_server_id: usize,
+    pub tags: Vec<DiagnosticTag>,
+    pub source: Option<String>,
+    pub data: Option<serde_json::Value>,
 }

helix-core/src/diff.rs

@@ -0,0 +1,221 @@
+use std::ops::Range;
+use std::time::Instant;
+
+use imara_diff::intern::InternedInput;
+use imara_diff::Algorithm;
+use ropey::RopeSlice;
+
+use crate::{ChangeSet, Rope, Tendril, Transaction};
+
+/// A `imara_diff::Sink` that builds a `ChangeSet` for a character diff of a hunk
+struct CharChangeSetBuilder<'a> {
+    res: &'a mut ChangeSet,
+    hunk: &'a InternedInput<char>,
+    pos: u32,
+}
+
+impl imara_diff::Sink for CharChangeSetBuilder<'_> {
+    type Out = ();
+    fn process_change(&mut self, before: Range<u32>, after: Range<u32>) {
+        self.res.retain((before.start - self.pos) as usize);
+        self.res.delete(before.len());
+        self.pos = before.end;
+
+        let res = self.hunk.after[after.start as usize..after.end as usize]
+            .iter()
+            .map(|&token| self.hunk.interner[token])
+            .collect();
+
+        self.res.insert(res);
+    }
+
+    fn finish(self) -> Self::Out {
+        self.res.retain(self.hunk.before.len() - self.pos as usize);
+    }
+}
+
+struct LineChangeSetBuilder<'a> {
+    res: ChangeSet,
+    after: RopeSlice<'a>,
+    file: &'a InternedInput<RopeSlice<'a>>,
+    current_hunk: InternedInput<char>,
+    pos: u32,
+}
+
+impl imara_diff::Sink for LineChangeSetBuilder<'_> {
+    type Out = ChangeSet;
+
+    fn process_change(&mut self, before: Range<u32>, after: Range<u32>) {
+        let len = self.file.before[self.pos as usize..before.start as usize]
+            .iter()
+            .map(|&it| self.file.interner[it].len_chars())
+            .sum();
+        self.res.retain(len);
+        self.pos = before.end;
+
+        // do not perform diffs on large hunks
+        let len_before = before.end - before.start;
+        let len_after = after.end - after.start;
+
+        // Pure insertions/removals do not require a character diff.
+        // Very large changes are ignored because their character diff is expensive to compute
+        // TODO adjust heuristic to detect large changes?
+        if len_before == 0
+            || len_after == 0
+            || len_after > 5 * len_before
+            || 5 * len_after < len_before && len_before > 10
+            || len_before + len_after > 200
+        {
+            let remove = self.file.before[before.start as usize..before.end as usize]
+                .iter()
+                .map(|&it| self.file.interner[it].len_chars())
+                .sum();
+            self.res.delete(remove);
+            let mut fragment = Tendril::new();
+            if len_after > 500 {
+                // copying a rope line by line is slower then copying the entire
+                // rope. Use to_string for very large changes instead..
+                if self.file.after.len() == after.end as usize {
+                    if after.start == 0 {
+                        fragment = self.after.to_string().into();
+                    } else {
+                        let start = self.after.line_to_char(after.start as usize);
+                        fragment = self.after.slice(start..).to_string().into();
+                    }
+                } else if after.start == 0 {
+                    let end = self.after.line_to_char(after.end as usize);
+                    fragment = self.after.slice(..end).to_string().into();
+                } else {
+                    let start = self.after.line_to_char(after.start as usize);
+                    let end = self.after.line_to_char(after.end as usize);
+                    fragment = self.after.slice(start..end).to_string().into();
+                }
+            } else {
+                for &line in &self.file.after[after.start as usize..after.end as usize] {
+                    for chunk in self.file.interner[line].chunks() {
+                        fragment.push_str(chunk)
+                    }
+                }
+            };
+            self.res.insert(fragment);
+        } else {
+            // for reasonably small hunks, generating a ChangeSet from char diff can save memory
+            // TODO use a tokenizer (word diff?) for improved performance
+            let hunk_before = self.file.before[before.start as usize..before.end as usize]
+                .iter()
+                .flat_map(|&it| self.file.interner[it].chars());
+            let hunk_after = self.file.after[after.start as usize..after.end as usize]
+                .iter()
+                .flat_map(|&it| self.file.interner[it].chars());
+            self.current_hunk.update_before(hunk_before);
+            self.current_hunk.update_after(hunk_after);
+
+            // the histogram heuristic does not work as well
+            // for characters because the same characters often reoccur
+            // use myer diff instead
+            imara_diff::diff(
+                Algorithm::Myers,
+                &self.current_hunk,
+                CharChangeSetBuilder {
+                    res: &mut self.res,
+                    hunk: &self.current_hunk,
+                    pos: 0,
+                },
+            );
+
+            self.current_hunk.clear();
+        }
+    }
+
+    fn finish(mut self) -> Self::Out {
+        let len = self.file.before[self.pos as usize..]
+            .iter()
+            .map(|&it| self.file.interner[it].len_chars())
+            .sum();
+
+        self.res.retain(len);
+        self.res
+    }
+}
+
+struct RopeLines<'a>(RopeSlice<'a>);
+
+impl<'a> imara_diff::intern::TokenSource for RopeLines<'a> {
+    type Token = RopeSlice<'a>;
+    type Tokenizer = ropey::iter::Lines<'a>;
+
+    fn tokenize(&self) -> Self::Tokenizer {
+        self.0.lines()
+    }
+
+    fn estimate_tokens(&self) -> u32 {
+        // we can provide a perfect estimate which is very nice for performance
+        self.0.len_lines() as u32
+    }
+}
+
+/// Compares `old` and `new` to generate a [`Transaction`] describing
+/// the steps required to get from `old` to `new`.
+pub fn compare_ropes(before: &Rope, after: &Rope) -> Transaction {
+    let start = Instant::now();
+    let res = ChangeSet::with_capacity(32);
+    let after = after.slice(..);
+    let file = InternedInput::new(RopeLines(before.slice(..)), RopeLines(after));
+    let builder = LineChangeSetBuilder {
+        res,
+        file: &file,
+        after,
+        pos: 0,
+        current_hunk: InternedInput::default(),
+    };
+
+    let res = imara_diff::diff(Algorithm::Histogram, &file, builder).into();
+
+    log::debug!(
+        "rope diff took {}s",
+        Instant::now().duration_since(start).as_secs_f64()
+    );
+    res
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn test_identity(a: &str, b: &str) {
+        let mut old = Rope::from(a);
+        let new = Rope::from(b);
+        compare_ropes(&old, &new).apply(&mut old);
+        assert_eq!(old, new);
+    }
+
+    quickcheck::quickcheck! {
+        fn test_compare_ropes(a: String, b: String) -> bool {
+            let mut old = Rope::from(a);
+            let new = Rope::from(b);
+            compare_ropes(&old, &new).apply(&mut old);
+            old == new
+        }
+    }
+
+    #[test]
+    fn equal_files() {
+        test_identity("foo", "foo");
+    }
+
+    #[test]
+    fn trailing_newline() {
+        test_identity("foo\n", "foo");
+        test_identity("foo", "foo\n");
+    }
+
+    #[test]
+    fn new_file() {
+        test_identity("", "foo");
+    }
+
+    #[test]
+    fn deleted_file() {
+        test_identity("foo", "");
+    }
+}

helix-core/src/doc_formatter.rs

@@ -0,0 +1,384 @@
+//! The `DocumentFormatter` forms the bridge between the raw document text
+//! and onscreen positioning. It yields the text graphemes as an iterator
+//! and traverses (part) of the document text. During that traversal it
+//! handles grapheme detection, softwrapping and annotations.
+//! It yields `FormattedGrapheme`s and their corresponding visual coordinates.
+//!
+//! As both virtual text and softwrapping can insert additional lines into the document
+//! it is generally not possible to find the start of the previous visual line.
+//! Instead the `DocumentFormatter` starts at the last "checkpoint" (usually a linebreak)
+//! called a "block" and the caller must advance it as needed.
+
+use std::borrow::Cow;
+use std::fmt::Debug;
+use std::mem::{replace, take};
+
+#[cfg(test)]
+mod test;
+
+use unicode_segmentation::{Graphemes, UnicodeSegmentation};
+
+use crate::graphemes::{Grapheme, GraphemeStr};
+use crate::syntax::Highlight;
+use crate::text_annotations::TextAnnotations;
+use crate::{Position, RopeGraphemes, RopeSlice};
+
+/// TODO make Highlight a u32 to reduce the size of this enum to a single word.
+#[derive(Debug, Clone, Copy)]
+pub enum GraphemeSource {
+    Document {
+        codepoints: u32,
+    },
+    /// Inline virtual text can not be highlighted with a `Highlight` iterator
+    /// because it's not part of the document. Instead the `Highlight`
+    /// is emitted right by the document formatter
+    VirtualText {
+        highlight: Option<Highlight>,
+    },
+}
+
+#[derive(Debug, Clone)]
+pub struct FormattedGrapheme<'a> {
+    pub grapheme: Grapheme<'a>,
+    pub source: GraphemeSource,
+}
+
+impl<'a> FormattedGrapheme<'a> {
+    pub fn new(
+        g: GraphemeStr<'a>,
+        visual_x: usize,
+        tab_width: u16,
+        source: GraphemeSource,
+    ) -> FormattedGrapheme<'a> {
+        FormattedGrapheme {
+            grapheme: Grapheme::new(g, visual_x, tab_width),
+            source,
+        }
+    }
+    /// Returns whether this grapheme is virtual inline text
+    pub fn is_virtual(&self) -> bool {
+        matches!(self.source, GraphemeSource::VirtualText { .. })
+    }
+
+    pub fn placeholder() -> Self {
+        FormattedGrapheme {
+            grapheme: Grapheme::Other { g: " ".into() },
+            source: GraphemeSource::Document { codepoints: 0 },
+        }
+    }
+
+    pub fn doc_chars(&self) -> usize {
+        match self.source {
+            GraphemeSource::Document { codepoints } => codepoints as usize,
+            GraphemeSource::VirtualText { .. } => 0,
+        }
+    }
+
+    pub fn is_whitespace(&self) -> bool {
+        self.grapheme.is_whitespace()
+    }
+
+    pub fn width(&self) -> usize {
+        self.grapheme.width()
+    }
+
+    pub fn is_word_boundary(&self) -> bool {
+        self.grapheme.is_word_boundary()
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct TextFormat {
+    pub soft_wrap: bool,
+    pub tab_width: u16,
+    pub max_wrap: u16,
+    pub max_indent_retain: u16,
+    pub wrap_indicator: Box<str>,
+    pub wrap_indicator_highlight: Option<Highlight>,
+    pub viewport_width: u16,
+}
+
+// test implementation is basically only used for testing or when softwrap is always disabled
+impl Default for TextFormat {
+    fn default() -> Self {
+        TextFormat {
+            soft_wrap: false,
+            tab_width: 4,
+            max_wrap: 3,
+            max_indent_retain: 4,
+            wrap_indicator: Box::from(" "),
+            viewport_width: 17,
+            wrap_indicator_highlight: None,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct DocumentFormatter<'t> {
+    text_fmt: &'t TextFormat,
+    annotations: &'t TextAnnotations,
+
+    /// The visual position at the end of the last yielded word boundary
+    visual_pos: Position,
+    graphemes: RopeGraphemes<'t>,
+    /// The character pos of the `graphemes` iter used for inserting annotations
+    char_pos: usize,
+    /// The line pos of the `graphemes` iter used for inserting annotations
+    line_pos: usize,
+    exhausted: bool,
+
+    /// Line breaks to be reserved for virtual text
+    /// at the next line break
+    virtual_lines: usize,
+    inline_anntoation_graphemes: Option<(Graphemes<'t>, Option<Highlight>)>,
+
+    // softwrap specific
+    /// The indentation of the current line
+    /// Is set to `None` if the indentation level is not yet known
+    /// because no non-whitespace graphemes have been encountered yet
+    indent_level: Option<usize>,
+    /// In case a long word needs to be split a single grapheme might need to be wrapped
+    /// while the rest of the word stays on the same line
+    peeked_grapheme: Option<(FormattedGrapheme<'t>, usize)>,
+    /// A first-in first-out (fifo) buffer for the Graphemes of any given word
+    word_buf: Vec<FormattedGrapheme<'t>>,
+    /// The index of the next grapheme that will be yielded from the `word_buf`
+    word_i: usize,
+}
+
+impl<'t> DocumentFormatter<'t> {
+    /// Creates a new formatter at the last block before `char_idx`.
+    /// A block is a chunk which always ends with a linebreak.
+    /// This is usually just a normal line break.
+    /// However very long lines are always wrapped at constant intervals that can be cheaply calculated
+    /// to avoid pathological behaviour.
+    pub fn new_at_prev_checkpoint(
+        text: RopeSlice<'t>,
+        text_fmt: &'t TextFormat,
+        annotations: &'t TextAnnotations,
+        char_idx: usize,
+    ) -> (Self, usize) {
+        // TODO divide long lines into blocks to avoid bad performance for long lines
+        let block_line_idx = text.char_to_line(char_idx.min(text.len_chars()));
+        let block_char_idx = text.line_to_char(block_line_idx);
+        annotations.reset_pos(block_char_idx);
+        (
+            DocumentFormatter {
+                text_fmt,
+                annotations,
+                visual_pos: Position { row: 0, col: 0 },
+                graphemes: RopeGraphemes::new(text.slice(block_char_idx..)),
+                char_pos: block_char_idx,
+                exhausted: false,
+                virtual_lines: 0,
+                indent_level: None,
+                peeked_grapheme: None,
+                word_buf: Vec::with_capacity(64),
+                word_i: 0,
+                line_pos: block_line_idx,
+                inline_anntoation_graphemes: None,
+            },
+            block_char_idx,
+        )
+    }
+
+    fn next_inline_annotation_grapheme(&mut self) -> Option<(&'t str, Option<Highlight>)> {
+        loop {
+            if let Some(&mut (ref mut annotation, highlight)) =
+                self.inline_anntoation_graphemes.as_mut()
+            {
+                if let Some(grapheme) = annotation.next() {
+                    return Some((grapheme, highlight));
+                }
+            }
+
+            if let Some((annotation, highlight)) =
+                self.annotations.next_inline_annotation_at(self.char_pos)
+            {
+                self.inline_anntoation_graphemes = Some((
+                    UnicodeSegmentation::graphemes(&*annotation.text, true),
+                    highlight,
+                ))
+            } else {
+                return None;
+            }
+        }
+    }
+
+    fn advance_grapheme(&mut self, col: usize) -> Option<FormattedGrapheme<'t>> {
+        let (grapheme, source) =
+            if let Some((grapheme, highlight)) = self.next_inline_annotation_grapheme() {
+                (grapheme.into(), GraphemeSource::VirtualText { highlight })
+            } else if let Some(grapheme) = self.graphemes.next() {
+                self.virtual_lines += self.annotations.annotation_lines_at(self.char_pos);
+                let codepoints = grapheme.len_chars() as u32;
+
+                let overlay = self.annotations.overlay_at(self.char_pos);
+                let grapheme = match overlay {
+                    Some((overlay, _)) => overlay.grapheme.as_str().into(),
+                    None => Cow::from(grapheme).into(),
+                };
+
+                self.char_pos += codepoints as usize;
+                (grapheme, GraphemeSource::Document { codepoints })
+            } else {
+                if self.exhausted {
+                    return None;
+                }
+                self.exhausted = true;
+                // EOF grapheme is required for rendering
+                // and correct position computations
+                return Some(FormattedGrapheme {
+                    grapheme: Grapheme::Other { g: " ".into() },
+                    source: GraphemeSource::Document { codepoints: 0 },
+                });
+            };
+
+        let grapheme = FormattedGrapheme::new(grapheme, col, self.text_fmt.tab_width, source);
+
+        Some(grapheme)
+    }
+
+    /// Move a word to the next visual line
+    fn wrap_word(&mut self, virtual_lines_before_word: usize) -> usize {
+        // softwrap this word to the next line
+        let indent_carry_over = if let Some(indent) = self.indent_level {
+            if indent as u16 <= self.text_fmt.max_indent_retain {
+                indent as u16
+            } else {
+                0
+            }
+        } else {
+            // ensure the indent stays 0
+            self.indent_level = Some(0);
+            0
+        };
+
+        self.visual_pos.col = indent_carry_over as usize;
+        self.virtual_lines -= virtual_lines_before_word;
+        self.visual_pos.row += 1 + virtual_lines_before_word;
+        let mut i = 0;
+        let mut word_width = 0;
+        let wrap_indicator = UnicodeSegmentation::graphemes(&*self.text_fmt.wrap_indicator, true)
+            .map(|g| {
+                i += 1;
+                let grapheme = FormattedGrapheme::new(
+                    g.into(),
+                    self.visual_pos.col + word_width,
+                    self.text_fmt.tab_width,
+                    GraphemeSource::VirtualText {
+                        highlight: self.text_fmt.wrap_indicator_highlight,
+                    },
+                );
+                word_width += grapheme.width();
+                grapheme
+            });
+        self.word_buf.splice(0..0, wrap_indicator);
+
+        for grapheme in &mut self.word_buf[i..] {
+            let visual_x = self.visual_pos.col + word_width;
+            grapheme
+                .grapheme
+                .change_position(visual_x, self.text_fmt.tab_width);
+            word_width += grapheme.width();
+        }
+        word_width
+    }
+
+    fn advance_to_next_word(&mut self) {
+        self.word_buf.clear();
+        let mut word_width = 0;
+        let virtual_lines_before_word = self.virtual_lines;
+        let mut virtual_lines_before_grapheme = self.virtual_lines;
+
+        loop {
+            // softwrap word if necessary
+            if word_width + self.visual_pos.col >= self.text_fmt.viewport_width as usize {
+                // wrapping this word would move too much text to the next line
+                // split the word at the line end instead
+                if word_width > self.text_fmt.max_wrap as usize {
+                    // Usually we stop accomulating graphemes as soon as softwrapping becomes necessary.
+                    // However if the last grapheme is multiple columns wide it might extend beyond the EOL.
+                    // The condition below ensures that this grapheme is not cutoff and instead wrapped to the next line
+                    if word_width + self.visual_pos.col > self.text_fmt.viewport_width as usize {
+                        self.peeked_grapheme = self.word_buf.pop().map(|grapheme| {
+                            (grapheme, self.virtual_lines - virtual_lines_before_grapheme)
+                        });
+                        self.virtual_lines = virtual_lines_before_grapheme;
+                    }
+                    return;
+                }
+
+                word_width = self.wrap_word(virtual_lines_before_word);
+            }
+
+            virtual_lines_before_grapheme = self.virtual_lines;
+
+            let grapheme = if let Some((grapheme, virtual_lines)) = self.peeked_grapheme.take() {
+                self.virtual_lines += virtual_lines;
+                grapheme
+            } else if let Some(grapheme) = self.advance_grapheme(self.visual_pos.col + word_width) {
+                grapheme
+            } else {
+                return;
+            };
+
+            // Track indentation
+            if !grapheme.is_whitespace() && self.indent_level.is_none() {
+                self.indent_level = Some(self.visual_pos.col);
+            } else if grapheme.grapheme == Grapheme::Newline {
+                self.indent_level = None;
+            }
+
+            let is_word_boundary = grapheme.is_word_boundary();
+            word_width += grapheme.width();
+            self.word_buf.push(grapheme);
+
+            if is_word_boundary {
+                return;
+            }
+        }
+    }
+
+    /// returns the document line pos of the **next** grapheme that will be yielded
+    pub fn line_pos(&self) -> usize {
+        self.line_pos
+    }
+
+    /// returns the visual pos of the **next** grapheme that will be yielded
+    pub fn visual_pos(&self) -> Position {
+        self.visual_pos
+    }
+}
+
+impl<'t> Iterator for DocumentFormatter<'t> {
+    type Item = (FormattedGrapheme<'t>, Position);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let grapheme = if self.text_fmt.soft_wrap {
+            if self.word_i >= self.word_buf.len() {
+                self.advance_to_next_word();
+                self.word_i = 0;
+            }
+            let grapheme = replace(
+                self.word_buf.get_mut(self.word_i)?,
+                FormattedGrapheme::placeholder(),
+            );
+            self.word_i += 1;
+            grapheme
+        } else {
+            self.advance_grapheme(self.visual_pos.col)?
+        };
+
+        let pos = self.visual_pos;
+        if grapheme.grapheme == Grapheme::Newline {
+            self.visual_pos.row += 1;
+            self.visual_pos.row += take(&mut self.virtual_lines);
+            self.visual_pos.col = 0;
+            self.line_pos += 1;
+        } else {
+            self.visual_pos.col += grapheme.width();
+        }
+        Some((grapheme, pos))
+    }
+}

helix-core/src/doc_formatter/test.rs

@@ -0,0 +1,182 @@
+use std::rc::Rc;
+
+use crate::doc_formatter::{DocumentFormatter, TextFormat};
+use crate::text_annotations::{InlineAnnotation, Overlay, TextAnnotations};
+
+impl TextFormat {
+    fn new_test(softwrap: bool) -> Self {
+        TextFormat {
+            soft_wrap: softwrap,
+            tab_width: 2,
+            max_wrap: 3,
+            max_indent_retain: 4,
+            wrap_indicator: ".".into(),
+            wrap_indicator_highlight: None,
+            // use a prime number to allow lining up too often with repeat
+            viewport_width: 17,
+        }
+    }
+}
+
+impl<'t> DocumentFormatter<'t> {
+    fn collect_to_str(&mut self) -> String {
+        use std::fmt::Write;
+        let mut res = String::new();
+        let viewport_width = self.text_fmt.viewport_width;
+        let mut line = 0;
+
+        for (grapheme, pos) in self {
+            if pos.row != line {
+                line += 1;
+                assert_eq!(pos.row, line);
+                write!(res, "\n{}", ".".repeat(pos.col)).unwrap();
+                assert!(
+                    pos.col <= viewport_width as usize,
+                    "softwrapped failed {}<={viewport_width}",
+                    pos.col
+                );
+            }
+            write!(res, "{}", grapheme.grapheme).unwrap();
+        }
+
+        res
+    }
+}
+
+fn softwrap_text(text: &str) -> String {
+    DocumentFormatter::new_at_prev_checkpoint(
+        text.into(),
+        &TextFormat::new_test(true),
+        &TextAnnotations::default(),
+        0,
+    )
+    .0
+    .collect_to_str()
+}
+
+#[test]
+fn basic_softwrap() {
+    assert_eq!(
+        softwrap_text(&"foo ".repeat(10)),
+        "foo foo foo foo \n.foo foo foo foo \n.foo foo  "
+    );
+    assert_eq!(
+        softwrap_text(&"fooo ".repeat(10)),
+        "fooo fooo fooo \n.fooo fooo fooo \n.fooo fooo fooo \n.fooo  "
+    );
+
+    // check that we don't wrap unnecessarily
+    assert_eq!(softwrap_text("\t\txxxx1xxxx2xx\n"), "    xxxx1xxxx2xx \n ");
+}
+
+#[test]
+fn softwrap_indentation() {
+    assert_eq!(
+        softwrap_text("\t\tfoo1 foo2 foo3 foo4 foo5 foo6\n"),
+        "    foo1 foo2 \n.....foo3 foo4 \n.....foo5 foo6 \n "
+    );
+    assert_eq!(
+        softwrap_text("\t\t\tfoo1 foo2 foo3 foo4 foo5 foo6\n"),
+        "      foo1 foo2 \n.foo3 foo4 foo5 \n.foo6 \n "
+    );
+}
+
+#[test]
+fn long_word_softwrap() {
+    assert_eq!(
+        softwrap_text("\t\txxxx1xxxx2xxxx3xxxx4xxxx5xxxx6xxxx7xxxx8xxxx9xxx\n"),
+        "    xxxx1xxxx2xxx\n.....x3xxxx4xxxx5\n.....xxxx6xxxx7xx\n.....xx8xxxx9xxx \n "
+    );
+    assert_eq!(
+        softwrap_text("xxxxxxxx1xxxx2xxx\n"),
+        "xxxxxxxx1xxxx2xxx\n. \n "
+    );
+    assert_eq!(
+        softwrap_text("\t\txxxx1xxxx 2xxxx3xxxx4xxxx5xxxx6xxxx7xxxx8xxxx9xxx\n"),
+        "    xxxx1xxxx \n.....2xxxx3xxxx4x\n.....xxx5xxxx6xxx\n.....x7xxxx8xxxx9\n.....xxx \n "
+    );
+    assert_eq!(
+        softwrap_text("\t\txxxx1xxx 2xxxx3xxxx4xxxx5xxxx6xxxx7xxxx8xxxx9xxx\n"),
+        "    xxxx1xxx 2xxx\n.....x3xxxx4xxxx5\n.....xxxx6xxxx7xx\n.....xx8xxxx9xxx \n "
+    );
+}
+
+fn overlay_text(text: &str, char_pos: usize, softwrap: bool, overlays: &[Overlay]) -> String {
+    DocumentFormatter::new_at_prev_checkpoint(
+        text.into(),
+        &TextFormat::new_test(softwrap),
+        TextAnnotations::default().add_overlay(overlays.into(), None),
+        char_pos,
+    )
+    .0
+    .collect_to_str()
+}
+
+#[test]
+fn overlay() {
+    assert_eq!(
+        overlay_text(
+            "foobar",
+            0,
+            false,
+            &[Overlay::new(0, "X"), Overlay::new(2, "\t")],
+        ),
+        "Xo  bar "
+    );
+    assert_eq!(
+        overlay_text(
+            &"foo ".repeat(10),
+            0,
+            true,
+            &[
+                Overlay::new(2, "\t"),
+                Overlay::new(5, "\t"),
+                Overlay::new(16, "X"),
+            ]
+        ),
+        "fo   f  o foo \n.foo Xoo foo foo \n.foo foo foo  "
+    );
+}
+
+fn annotate_text(text: &str, softwrap: bool, annotations: &[InlineAnnotation]) -> String {
+    DocumentFormatter::new_at_prev_checkpoint(
+        text.into(),
+        &TextFormat::new_test(softwrap),
+        TextAnnotations::default().add_inline_annotations(annotations.into(), None),
+        0,
+    )
+    .0
+    .collect_to_str()
+}
+
+#[test]
+fn annotation() {
+    assert_eq!(
+        annotate_text("bar", false, &[InlineAnnotation::new(0, "foo")]),
+        "foobar "
+    );
+    assert_eq!(
+        annotate_text(
+            &"foo ".repeat(10),
+            true,
+            &[InlineAnnotation::new(0, "foo ")]
+        ),
+        "foo foo foo foo \n.foo foo foo foo \n.foo foo foo  "
+    );
+}
+#[test]
+fn annotation_and_overlay() {
+    assert_eq!(
+        DocumentFormatter::new_at_prev_checkpoint(
+            "bbar".into(),
+            &TextFormat::new_test(false),
+            TextAnnotations::default()
+                .add_inline_annotations(Rc::new([InlineAnnotation::new(0, "fooo")]), None)
+                .add_overlay(Rc::new([Overlay::new(0, "\t")]), None),
+            0,
+        )
+        .0
+        .collect_to_str(),
+        "fooo  bar "
+    );
+}

helix-core/src/fuzzy.rs

@@ -0,0 +1,43 @@
+use std::ops::DerefMut;
+
+use nucleo::pattern::{Atom, AtomKind, CaseMatching};
+use nucleo::Config;
+use parking_lot::Mutex;
+
+pub struct LazyMutex<T> {
+    inner: Mutex<Option<T>>,
+    init: fn() -> T,
+}
+
+impl<T> LazyMutex<T> {
+    pub const fn new(init: fn() -> T) -> Self {
+        Self {
+            inner: Mutex::new(None),
+            init,
+        }
+    }
+
+    pub fn lock(&self) -> impl DerefMut<Target = T> + '_ {
+        parking_lot::MutexGuard::map(self.inner.lock(), |val| val.get_or_insert_with(self.init))
+    }
+}
+
+pub static MATCHER: LazyMutex<nucleo::Matcher> = LazyMutex::new(nucleo::Matcher::default);
+
+/// convenience function to easily fuzzy match
+/// on a (relatively small list of inputs). This is not recommended for building a full tui
+/// application that can match large numbers of matches as all matching is done on the current
+/// thread, effectively blocking the UI
+pub fn fuzzy_match<T: AsRef<str>>(
+    pattern: &str,
+    items: impl IntoIterator<Item = T>,
+    path: bool,
+) -> Vec<(T, u16)> {
+    let mut matcher = MATCHER.lock();
+    matcher.config = Config::DEFAULT;
+    if path {
+        matcher.config.set_match_paths();
+    }
+    let pattern = Atom::new(pattern, CaseMatching::Smart, AtomKind::Fuzzy, false);
+    pattern.match_list(items, &mut matcher)
+}

helix-core/src/graphemes.rs

@@ -1,8 +1,93 @@
-// Based on https://github.com/cessen/led/blob/c4fa72405f510b7fd16052f90a598c429b3104a6/src/graphemes.rs
+//! Utility functions to traverse the unicode graphemes of a `Rope`'s text contents.
+//!
+//! Based on <https://github.com/cessen/led/blob/c4fa72405f510b7fd16052f90a598c429b3104a6/src/graphemes.rs>
 use ropey::{iter::Chunks, str_utils::byte_to_char_idx, RopeSlice};
 use unicode_segmentation::{GraphemeCursor, GraphemeIncomplete};
 use unicode_width::UnicodeWidthStr;
 
+use std::borrow::Cow;
+use std::fmt::{self, Debug, Display};
+use std::marker::PhantomData;
+use std::ops::Deref;
+use std::ptr::NonNull;
+use std::{slice, str};
+
+use crate::chars::{char_is_whitespace, char_is_word};
+use crate::LineEnding;
+
+#[inline]
+pub fn tab_width_at(visual_x: usize, tab_width: u16) -> usize {
+    tab_width as usize - (visual_x % tab_width as usize)
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Grapheme<'a> {
+    Newline,
+    Tab { width: usize },
+    Other { g: GraphemeStr<'a> },
+}
+
+impl<'a> Grapheme<'a> {
+    pub fn new(g: GraphemeStr<'a>, visual_x: usize, tab_width: u16) -> Grapheme<'a> {
+        match g {
+            g if g == "\t" => Grapheme::Tab {
+                width: tab_width_at(visual_x, tab_width),
+            },
+            _ if LineEnding::from_str(&g).is_some() => Grapheme::Newline,
+            _ => Grapheme::Other { g },
+        }
+    }
+
+    pub fn change_position(&mut self, visual_x: usize, tab_width: u16) {
+        if let Grapheme::Tab { width } = self {
+            *width = tab_width_at(visual_x, tab_width)
+        }
+    }
+
+    /// Returns the a visual width of this grapheme,
+    #[inline]
+    pub fn width(&self) -> usize {
+        match *self {
+            // width is not cached because we are dealing with
+            // ASCII almost all the time which already has a fastpath
+            // it's okay to convert to u16 here because no codepoint has a width larger
+            // than 2 and graphemes are usually atmost two visible codepoints wide
+            Grapheme::Other { ref g } => grapheme_width(g),
+            Grapheme::Tab { width } => width,
+            Grapheme::Newline => 1,
+        }
+    }
+
+    pub fn is_whitespace(&self) -> bool {
+        !matches!(&self, Grapheme::Other { g } if !g.chars().all(char_is_whitespace))
+    }
+
+    // TODO currently word boundaries are used for softwrapping.
+    // This works best for programming languages and well for prose.
+    // This could however be improved in the future by considering unicode
+    // character classes but
+    pub fn is_word_boundary(&self) -> bool {
+        !matches!(&self, Grapheme::Other { g,.. } if g.chars().all(char_is_word))
+    }
+}
+
+impl Display for Grapheme<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match *self {
+            Grapheme::Newline => write!(f, " "),
+            Grapheme::Tab { width } => {
+                for _ in 0..width {
+                    write!(f, " ")?;
+                }
+                Ok(())
+            }
+            Grapheme::Other { ref g } => {
+                write!(f, "{g}")
+            }
+        }
+    }
+}
+
 #[must_use]
 pub fn grapheme_width(g: &str) -> usize {
     if g.as_bytes()[0] <= 127 {
@@ -10,7 +95,7 @@ pub fn grapheme_width(g: &str) -> usize {
         // Point 1: theoretically, ascii control characters should have zero
         // width, but in our case we actually want them to have width: if they
         // show up in text, we want to treat them as textual elements that can
-        // be editied.  So we can get away with making all ascii single width
+        // be edited.  So we can get away with making all ascii single width
         // here.
         // Point 2: we're only examining the first codepoint here, which means
         // we're ignoring graphemes formed with combining characters.  However,
@@ -23,6 +108,8 @@ pub fn grapheme_width(g: &str) -> usize {
         // We use max(1) here because all grapeheme clusters--even illformed
         // ones--should have at least some width so they can be edited
         // properly.
+        // TODO properly handle unicode width for all codepoints
+        // example of where unicode width is currently wrong: 🤦🏼‍♂️ (taken from https://hsivonen.fi/string-length/)
         UnicodeWidthStr::width(g).max(1)
     }
 }
@@ -69,6 +156,8 @@ pub fn nth_prev_grapheme_boundary(slice: RopeSlice, char_idx: usize, n: usize) -
 }
 
 /// Finds the previous grapheme boundary before the given char position.
+#[must_use]
+#[inline(always)]
 pub fn prev_grapheme_boundary(slice: RopeSlice, char_idx: usize) -> usize {
     nth_prev_grapheme_boundary(slice, char_idx, 1)
 }
@@ -114,12 +203,100 @@ pub fn nth_next_grapheme_boundary(slice: RopeSlice, char_idx: usize, n: usize) -
     chunk_char_idx + tmp
 }
 
+#[must_use]
+pub fn nth_next_grapheme_boundary_byte(slice: RopeSlice, mut byte_idx: usize, n: usize) -> usize {
+    // Bounds check
+    debug_assert!(byte_idx <= slice.len_bytes());
+
+    // Get the chunk with our byte index in it.
+    let (mut chunk, mut chunk_byte_idx, mut _chunk_char_idx, _) = slice.chunk_at_byte(byte_idx);
+
+    // Set up the grapheme cursor.
+    let mut gc = GraphemeCursor::new(byte_idx, slice.len_bytes(), true);
+
+    // Find the nth next grapheme cluster boundary.
+    for _ in 0..n {
+        loop {
+            match gc.next_boundary(chunk, chunk_byte_idx) {
+                Ok(None) => return slice.len_bytes(),
+                Ok(Some(n)) => {
+                    byte_idx = n;
+                    break;
+                }
+                Err(GraphemeIncomplete::NextChunk) => {
+                    chunk_byte_idx += chunk.len();
+                    let (a, _, _c, _) = slice.chunk_at_byte(chunk_byte_idx);
+                    chunk = a;
+                    // chunk_char_idx = c;
+                }
+                Err(GraphemeIncomplete::PreContext(n)) => {
+                    let ctx_chunk = slice.chunk_at_byte(n - 1).0;
+                    gc.provide_context(ctx_chunk, n - ctx_chunk.len());
+                }
+                _ => unreachable!(),
+            }
+        }
+    }
+    byte_idx
+}
+
 /// Finds the next grapheme boundary after the given char position.
+#[must_use]
+#[inline(always)]
 pub fn next_grapheme_boundary(slice: RopeSlice, char_idx: usize) -> usize {
     nth_next_grapheme_boundary(slice, char_idx, 1)
 }
 
+/// Finds the next grapheme boundary after the given byte position.
+#[must_use]
+#[inline(always)]
+pub fn next_grapheme_boundary_byte(slice: RopeSlice, byte_idx: usize) -> usize {
+    nth_next_grapheme_boundary_byte(slice, byte_idx, 1)
+}
+
+/// Returns the passed char index if it's already a grapheme boundary,
+/// or the next grapheme boundary char index if not.
+#[must_use]
+#[inline]
+pub fn ensure_grapheme_boundary_next(slice: RopeSlice, char_idx: usize) -> usize {
+    if char_idx == 0 {
+        char_idx
+    } else {
+        next_grapheme_boundary(slice, char_idx - 1)
+    }
+}
+
+/// Returns the passed char index if it's already a grapheme boundary,
+/// or the prev grapheme boundary char index if not.
+#[must_use]
+#[inline]
+pub fn ensure_grapheme_boundary_prev(slice: RopeSlice, char_idx: usize) -> usize {
+    if char_idx == slice.len_chars() {
+        char_idx
+    } else {
+        prev_grapheme_boundary(slice, char_idx + 1)
+    }
+}
+
+/// Returns the passed byte index if it's already a grapheme boundary,
+/// or the next grapheme boundary byte index if not.
+#[must_use]
+#[inline]
+pub fn ensure_grapheme_boundary_next_byte(slice: RopeSlice, byte_idx: usize) -> usize {
+    if byte_idx == 0 {
+        byte_idx
+    } else {
+        // TODO: optimize so we're not constructing grapheme cursor twice
+        if is_grapheme_boundary_byte(slice, byte_idx) {
+            byte_idx
+        } else {
+            next_grapheme_boundary_byte(slice, byte_idx)
+        }
+    }
+}
+
 /// Returns whether the given char position is a grapheme boundary.
+#[must_use]
 pub fn is_grapheme_boundary(slice: RopeSlice, char_idx: usize) -> bool {
     // Bounds check
     debug_assert!(char_idx <= slice.len_chars());
@@ -146,6 +323,31 @@ pub fn is_grapheme_boundary(slice: RopeSlice, char_idx: usize) -> bool {
     }
 }
 
+/// Returns whether the given byte position is a grapheme boundary.
+#[must_use]
+pub fn is_grapheme_boundary_byte(slice: RopeSlice, byte_idx: usize) -> bool {
+    // Bounds check
+    debug_assert!(byte_idx <= slice.len_bytes());
+
+    // Get the chunk with our byte index in it.
+    let (chunk, chunk_byte_idx, _, _) = slice.chunk_at_byte(byte_idx);
+
+    // Set up the grapheme cursor.
+    let mut gc = GraphemeCursor::new(byte_idx, slice.len_bytes(), true);
+
+    // Determine if the given position is a grapheme cluster boundary.
+    loop {
+        match gc.is_boundary(chunk, chunk_byte_idx) {
+            Ok(n) => return n,
+            Err(GraphemeIncomplete::PreContext(n)) => {
+                let (ctx_chunk, ctx_byte_start, _, _) = slice.chunk_at_byte(n - 1);
+                gc.provide_context(ctx_chunk, ctx_byte_start);
+            }
+            Err(_) => unreachable!(),
+        }
+    }
+}
+
 /// An iterator over the graphemes of a `RopeSlice`.
 #[derive(Clone)]
 pub struct RopeGraphemes<'a> {
@@ -156,6 +358,18 @@ pub struct RopeGraphemes<'a> {
     cursor: GraphemeCursor,
 }
 
+impl<'a> fmt::Debug for RopeGraphemes<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("RopeGraphemes")
+            .field("text", &self.text)
+            .field("chunks", &self.chunks)
+            .field("cur_chunk", &self.cur_chunk)
+            .field("cur_chunk_start", &self.cur_chunk_start)
+            // .field("cursor", &self.cursor)
+            .finish()
+    }
+}
+
 impl<'a> RopeGraphemes<'a> {
     #[must_use]
     pub fn new(slice: RopeSlice) -> RopeGraphemes {
@@ -193,15 +407,16 @@ impl<'a> Iterator for RopeGraphemes<'a> {
                     self.cur_chunk_start += self.cur_chunk.len();
                     self.cur_chunk = self.chunks.next().unwrap_or("");
                 }
+                Err(GraphemeIncomplete::PreContext(idx)) => {
+                    let (chunk, byte_idx, _, _) = self.text.chunk_at_byte(idx.saturating_sub(1));
+                    self.cursor.provide_context(chunk, byte_idx);
+                }
                 _ => unreachable!(),
             }
         }
 
         if a < self.cur_chunk_start {
-            let a_char = self.text.byte_to_char(a);
-            let b_char = self.text.byte_to_char(b);
-
-            Some(self.text.slice(a_char..b_char))
+            Some(self.text.byte_slice(a..b))
         } else {
             let a2 = a - self.cur_chunk_start;
             let b2 = b - self.cur_chunk_start;
@@ -209,3 +424,101 @@ impl<'a> Iterator for RopeGraphemes<'a> {
         }
     }
 }
+
+/// A highly compressed Cow<'a, str> that holds
+/// atmost u31::MAX bytes and is readonly
+pub struct GraphemeStr<'a> {
+    ptr: NonNull<u8>,
+    len: u32,
+    phantom: PhantomData<&'a str>,
+}
+
+impl GraphemeStr<'_> {
+    const MASK_OWNED: u32 = 1 << 31;
+
+    fn compute_len(&self) -> usize {
+        (self.len & !Self::MASK_OWNED) as usize
+    }
+}
+
+impl Deref for GraphemeStr<'_> {
+    type Target = str;
+    fn deref(&self) -> &Self::Target {
+        unsafe {
+            let bytes = slice::from_raw_parts(self.ptr.as_ptr(), self.compute_len());
+            str::from_utf8_unchecked(bytes)
+        }
+    }
+}
+
+impl Drop for GraphemeStr<'_> {
+    fn drop(&mut self) {
+        if self.len & Self::MASK_OWNED != 0 {
+            // free allocation
+            unsafe {
+                drop(Box::from_raw(slice::from_raw_parts_mut(
+                    self.ptr.as_ptr(),
+                    self.compute_len(),
+                )));
+            }
+        }
+    }
+}
+
+impl<'a> From<&'a str> for GraphemeStr<'a> {
+    fn from(g: &'a str) -> Self {
+        GraphemeStr {
+            ptr: unsafe { NonNull::new_unchecked(g.as_bytes().as_ptr() as *mut u8) },
+            len: i32::try_from(g.len()).unwrap() as u32,
+            phantom: PhantomData,
+        }
+    }
+}
+
+impl<'a> From<String> for GraphemeStr<'a> {
+    fn from(g: String) -> Self {
+        let len = g.len();
+        let ptr = Box::into_raw(g.into_bytes().into_boxed_slice()) as *mut u8;
+        GraphemeStr {
+            ptr: unsafe { NonNull::new_unchecked(ptr) },
+            len: (i32::try_from(len).unwrap() as u32) | Self::MASK_OWNED,
+            phantom: PhantomData,
+        }
+    }
+}
+
+impl<'a> From<Cow<'a, str>> for GraphemeStr<'a> {
+    fn from(g: Cow<'a, str>) -> Self {
+        match g {
+            Cow::Borrowed(g) => g.into(),
+            Cow::Owned(g) => g.into(),
+        }
+    }
+}
+
+impl<T: Deref<Target = str>> PartialEq<T> for GraphemeStr<'_> {
+    fn eq(&self, other: &T) -> bool {
+        self.deref() == other.deref()
+    }
+}
+impl PartialEq<str> for GraphemeStr<'_> {
+    fn eq(&self, other: &str) -> bool {
+        self.deref() == other
+    }
+}
+impl Eq for GraphemeStr<'_> {}
+impl Debug for GraphemeStr<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        Debug::fmt(self.deref(), f)
+    }
+}
+impl Display for GraphemeStr<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        Display::fmt(self.deref(), f)
+    }
+}
+impl Clone for GraphemeStr<'_> {
+    fn clone(&self) -> Self {
+        self.deref().to_owned().into()
+    }
+}

helix-core/src/history.rs

@@ -1,19 +1,68 @@
-use crate::{ChangeSet, Rope, State, Transaction};
-use smallvec::{smallvec, SmallVec};
+use crate::{Assoc, ChangeSet, Range, Rope, Selection, Transaction};
+use once_cell::sync::Lazy;
+use regex::Regex;
+use std::num::NonZeroUsize;
+use std::time::{Duration, Instant};
 
-/// Undo-tree style history store.
-pub struct History {
-    revisions: Vec<Revision>,
-    cursor: usize,
+#[derive(Debug, Clone)]
+pub struct State {
+    pub doc: Rope,
+    pub selection: Selection,
 }
 
+/// Stores the history of changes to a buffer.
+///
+/// Currently the history is represented as a vector of revisions. The vector
+/// always has at least one element: the empty root revision. Each revision
+/// with the exception of the root has a parent revision, a [Transaction]
+/// that can be applied to its parent to transition from the parent to itself,
+/// and an inversion of that transaction to transition from the parent to its
+/// latest child.
+///
+/// When using `u` to undo a change, an inverse of the stored transaction will
+/// be applied which will transition the buffer to the parent state.
+///
+/// Each revision with the exception of the last in the vector also has a
+/// last child revision. When using `U` to redo a change, the last child transaction
+/// will be applied to the current state of the buffer.
+///
+/// The current revision is the one currently displayed in the buffer.
+///
+/// Committing a new revision to the history will update the last child of the
+/// current revision, and push a new revision to the end of the vector.
+///
+/// Revisions are committed with a timestamp. :earlier and :later can be used
+/// to jump to the closest revision to a moment in time relative to the timestamp
+/// of the current revision plus (:later) or minus (:earlier) the duration
+/// given to the command. If a single integer is given, the editor will instead
+/// jump the given number of revisions in the vector.
+///
+/// Limitations:
+///  * Changes in selections currently don't commit history changes. The selection
+///    will only be updated to the state after a committed buffer change.
+///  * The vector of history revisions is currently unbounded. This might
+///    cause the memory consumption to grow significantly large during long
+///    editing sessions.
+///  * Because delete transactions currently don't store the text that they
+///    delete, we also store an inversion of the transaction.
+///
+/// Using time to navigate the history: <https://github.com/helix-editor/helix/pull/194>
 #[derive(Debug)]
+pub struct History {
+    revisions: Vec<Revision>,
+    current: usize,
+}
+
+/// A single point in history. See [History] for more information.
+#[derive(Debug, Clone)]
 struct Revision {
     parent: usize,
-    children: SmallVec<[(usize, Transaction); 1]>,
-    /// The transaction to revert to previous state.
-    revert: Transaction,
-    // selection before, selection after?
+    last_child: Option<NonZeroUsize>,
+    transaction: Transaction,
+    // We need an inversion for undos because delete transactions don't store
+    // the deleted text.
+    inversion: Transaction,
+    timestamp: Instant,
 }
 
 impl Default for History {
@@ -22,86 +71,332 @@ impl Default for History {
         Self {
             revisions: vec![Revision {
                 parent: 0,
-                children: SmallVec::new(),
-                revert: Transaction::from(ChangeSet::new(&Rope::new())),
+                last_child: None,
+                transaction: Transaction::from(ChangeSet::new("".into())),
+                inversion: Transaction::from(ChangeSet::new("".into())),
+                timestamp: Instant::now(),
             }],
-            cursor: 0,
+            current: 0,
         }
     }
 }
 
 impl History {
     pub fn commit_revision(&mut self, transaction: &Transaction, original: &State) {
-        // TODO: could store a single transaction, if deletes also stored the text they delete
-        let revert = transaction
+        self.commit_revision_at_timestamp(transaction, original, Instant::now());
+    }
+
+    pub fn commit_revision_at_timestamp(
+        &mut self,
+        transaction: &Transaction,
+        original: &State,
+        timestamp: Instant,
+    ) {
+        let inversion = transaction
             .invert(&original.doc)
             // Store the current cursor position
             .with_selection(original.selection.clone());
 
-        let new_cursor = self.revisions.len();
+        let new_current = self.revisions.len();
+        self.revisions[self.current].last_child = NonZeroUsize::new(new_current);
         self.revisions.push(Revision {
-            parent: self.cursor,
-            children: SmallVec::new(),
-            revert,
+            parent: self.current,
+            last_child: None,
+            transaction: transaction.clone(),
+            inversion,
+            timestamp,
         });
-
-        // add a reference to the parent
-        self.revisions
-            .get_mut(self.cursor)
-            .unwrap() // TODO: get_unchecked_mut
-            .children
-            .push((new_cursor, transaction.clone()));
-
-        self.cursor = new_cursor;
+        self.current = new_current;
     }
 
     #[inline]
     pub fn current_revision(&self) -> usize {
-        self.cursor
+        self.current
     }
 
     #[inline]
     pub const fn at_root(&self) -> bool {
-        self.cursor == 0
+        self.current == 0
     }
 
-    // TODO: I'd like to pass Transaction by reference but it fights with the borrowck
+    /// Returns the changes since the given revision composed into a transaction.
+    /// Returns None if there are no changes between the current and given revisions.
+    pub fn changes_since(&self, revision: usize) -> Option<Transaction> {
+        let lca = self.lowest_common_ancestor(revision, self.current);
+        let up = self.path_up(revision, lca);
+        let down = self.path_up(self.current, lca);
+        let up_txns = up
+            .iter()
+            .rev()
+            .map(|&n| self.revisions[n].inversion.clone());
+        let down_txns = down.iter().map(|&n| self.revisions[n].transaction.clone());
 
-    pub fn undo(&mut self) -> Option<Transaction> {
+        down_txns.chain(up_txns).reduce(|acc, tx| tx.compose(acc))
+    }
+
+    /// Undo the last edit.
+    pub fn undo(&mut self) -> Option<&Transaction> {
         if self.at_root() {
-            // We're at the root of undo, nothing to do.
             return None;
         }
 
-        let current_revision = &self.revisions[self.cursor];
-
-        self.cursor = current_revision.parent;
-
-        Some(current_revision.revert.clone())
+        let current_revision = &self.revisions[self.current];
+        self.current = current_revision.parent;
+        Some(&current_revision.inversion)
     }
 
-    pub fn redo(&mut self) -> Option<Transaction> {
-        let current_revision = &self.revisions[self.cursor];
+    /// Redo the last edit.
+    pub fn redo(&mut self) -> Option<&Transaction> {
+        let current_revision = &self.revisions[self.current];
+        let last_child = current_revision.last_child?;
+        self.current = last_child.get();
 
-        // for now, simply pick the latest child (linear undo / redo)
-        if let Some((index, transaction)) = current_revision.children.last() {
-            self.cursor = *index;
+        Some(&self.revisions[last_child.get()].transaction)
+    }
 
-            return Some(transaction.clone());
+    // Get the position of last change
+    pub fn last_edit_pos(&self) -> Option<usize> {
+        if self.current == 0 {
+            return None;
+        }
+        let current_revision = &self.revisions[self.current];
+        let primary_selection = current_revision
+            .inversion
+            .selection()
+            .expect("inversion always contains a selection")
+            .primary();
+        let (_from, to, _fragment) = current_revision
+            .transaction
+            .changes_iter()
+            // find a change that matches the primary selection
+            .find(|(from, to, _fragment)| Range::new(*from, *to).overlaps(&primary_selection))
+            // or use the first change
+            .or_else(|| current_revision.transaction.changes_iter().next())
+            .unwrap();
+        let pos = current_revision
+            .transaction
+            .changes()
+            .map_pos(to, Assoc::After);
+        Some(pos)
+    }
+
+    fn lowest_common_ancestor(&self, mut a: usize, mut b: usize) -> usize {
+        use std::collections::HashSet;
+        let mut a_path_set = HashSet::new();
+        let mut b_path_set = HashSet::new();
+        loop {
+            a_path_set.insert(a);
+            b_path_set.insert(b);
+            if a_path_set.contains(&b) {
+                return b;
+            }
+            if b_path_set.contains(&a) {
+                return a;
+            }
+            a = self.revisions[a].parent; // Relies on the parent of 0 being 0.
+            b = self.revisions[b].parent; // Same as above.
+        }
+    }
+
+    /// List of nodes on the way from `n` to 'a`. Doesn't include `a`.
+    /// Includes `n` unless `a == n`. `a` must be an ancestor of `n`.
+    fn path_up(&self, mut n: usize, a: usize) -> Vec<usize> {
+        let mut path = Vec::new();
+        while n != a {
+            path.push(n);
+            n = self.revisions[n].parent;
+        }
+        path
+    }
+
+    /// Create a [`Transaction`] that will jump to a specific revision in the history.
+    fn jump_to(&mut self, to: usize) -> Vec<Transaction> {
+        let lca = self.lowest_common_ancestor(self.current, to);
+        let up = self.path_up(self.current, lca);
+        let down = self.path_up(to, lca);
+        self.current = to;
+        let up_txns = up.iter().map(|&n| self.revisions[n].inversion.clone());
+        let down_txns = down
+            .iter()
+            .rev()
+            .map(|&n| self.revisions[n].transaction.clone());
+        up_txns.chain(down_txns).collect()
+    }
+
+    /// Creates a [`Transaction`] that will undo `delta` revisions.
+    fn jump_backward(&mut self, delta: usize) -> Vec<Transaction> {
+        self.jump_to(self.current.saturating_sub(delta))
+    }
+
+    /// Creates a [`Transaction`] that will redo `delta` revisions.
+    fn jump_forward(&mut self, delta: usize) -> Vec<Transaction> {
+        self.jump_to(
+            self.current
+                .saturating_add(delta)
+                .min(self.revisions.len() - 1),
+        )
+    }
+
+    /// Helper for a binary search case below.
+    fn revision_closer_to_instant(&self, i: usize, instant: Instant) -> usize {
+        let dur_im1 = instant.duration_since(self.revisions[i - 1].timestamp);
+        let dur_i = self.revisions[i].timestamp.duration_since(instant);
+        use std::cmp::Ordering::*;
+        match dur_im1.cmp(&dur_i) {
+            Less => i - 1,
+            Equal | Greater => i,
+        }
+    }
+
+    /// Creates a [`Transaction`] that will match a revision created at around
+    /// `instant`.
+    fn jump_instant(&mut self, instant: Instant) -> Vec<Transaction> {
+        let search_result = self
+            .revisions
+            .binary_search_by(|rev| rev.timestamp.cmp(&instant));
+        let revision = match search_result {
+            Ok(revision) => revision,
+            Err(insert_point) => match insert_point {
+                0 => 0,
+                n if n == self.revisions.len() => n - 1,
+                i => self.revision_closer_to_instant(i, instant),
+            },
+        };
+        self.jump_to(revision)
+    }
+
+    /// Creates a [`Transaction`] that will match a revision created `duration` ago
+    /// from the timestamp of current revision.
+    fn jump_duration_backward(&mut self, duration: Duration) -> Vec<Transaction> {
+        match self.revisions[self.current].timestamp.checked_sub(duration) {
+            Some(instant) => self.jump_instant(instant),
+            None => self.jump_to(0),
+        }
+    }
+
+    /// Creates a [`Transaction`] that will match a revision created `duration` in
+    /// the future from the timestamp of the current revision.
+    fn jump_duration_forward(&mut self, duration: Duration) -> Vec<Transaction> {
+        match self.revisions[self.current].timestamp.checked_add(duration) {
+            Some(instant) => self.jump_instant(instant),
+            None => self.jump_to(self.revisions.len() - 1),
+        }
+    }
+
+    /// Creates an undo [`Transaction`].
+    pub fn earlier(&mut self, uk: UndoKind) -> Vec<Transaction> {
+        use UndoKind::*;
+        match uk {
+            Steps(n) => self.jump_backward(n),
+            TimePeriod(d) => self.jump_duration_backward(d),
+        }
+    }
+
+    /// Creates a redo [`Transaction`].
+    pub fn later(&mut self, uk: UndoKind) -> Vec<Transaction> {
+        use UndoKind::*;
+        match uk {
+            Steps(n) => self.jump_forward(n),
+            TimePeriod(d) => self.jump_duration_forward(d),
+        }
+    }
+}
+
+/// Whether to undo by a number of edits or a duration of time.
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum UndoKind {
+    Steps(usize),
+    TimePeriod(std::time::Duration),
+}
+
+/// A subset of systemd.time time span syntax units.
+const TIME_UNITS: &[(&[&str], &str, u64)] = &[
+    (&["seconds", "second", "sec", "s"], "seconds", 1),
+    (&["minutes", "minute", "min", "m"], "minutes", 60),
+    (&["hours", "hour", "hr", "h"], "hours", 60 * 60),
+    (&["days", "day", "d"], "days", 24 * 60 * 60),
+];
+
+/// Checks if the duration input can be turned into a valid duration. It must be a
+/// positive integer and denote the [unit of time.](`TIME_UNITS`)
+/// Examples of valid durations:
+///  * `5 sec`
+///  * `5 min`
+///  * `5 hr`
+///  * `5 days`
+static DURATION_VALIDATION_REGEX: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r"^(?:\d+\s*[a-z]+\s*)+$").unwrap());
+
+/// Captures both the number and unit as separate capture groups.
+static NUMBER_UNIT_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"(\d+)\s*([a-z]+)").unwrap());
+
+/// Parse a string (e.g. "5 sec") and try to convert it into a [`Duration`].
+fn parse_human_duration(s: &str) -> Result<Duration, String> {
+    if !DURATION_VALIDATION_REGEX.is_match(s) {
+        return Err("duration should be composed \
+        of positive integers followed by time units"
+            .to_string());
+    }
+
+    let mut specified = [false; TIME_UNITS.len()];
+    let mut seconds = 0u64;
+    for cap in NUMBER_UNIT_REGEX.captures_iter(s) {
+        let (n, unit_str) = (&cap[1], &cap[2]);
+
+        let n: u64 = n.parse().map_err(|_| format!("integer too large: {}", n))?;
+
+        let time_unit = TIME_UNITS
+            .iter()
+            .enumerate()
+            .find(|(_, (forms, _, _))| forms.iter().any(|f| f == &unit_str));
+
+        if let Some((i, (_, unit, mul))) = time_unit {
+            if specified[i] {
+                return Err(format!("{} specified more than once", unit));
+            }
+            specified[i] = true;
+
+            let new_seconds = n.checked_mul(*mul).and_then(|s| seconds.checked_add(s));
+            match new_seconds {
+                Some(ns) => seconds = ns,
+                None => return Err("duration too large".to_string()),
+            }
+        } else {
+            return Err(format!("incorrect time unit: {}", unit_str));
+        }
+    }
+
+    Ok(Duration::from_secs(seconds))
+}
+
+impl std::str::FromStr for UndoKind {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let s = s.trim();
+        if s.is_empty() {
+            Ok(Self::Steps(1usize))
+        } else if let Ok(n) = s.parse::<usize>() {
+            Ok(UndoKind::Steps(n))
+        } else {
+            Ok(Self::TimePeriod(parse_human_duration(s)?))
         }
-        None
     }
 }
 
 #[cfg(test)]
 mod test {
     use super::*;
+    use crate::Selection;
 
     #[test]
     fn test_undo_redo() {
         let mut history = History::default();
         let doc = Rope::from("hello");
-        let mut state = State::new(doc);
+        let mut state = State {
+            doc,
+            selection: Selection::point(0),
+        };
 
         let transaction1 =
             Transaction::change(&state.doc, vec![(5, 5, Some(" world!".into()))].into_iter());
@@ -145,4 +440,194 @@ mod test {
         undo(&mut history, &mut state);
         assert_eq!("hello", state.doc);
     }
+
+    #[test]
+    fn test_earlier_later() {
+        let mut history = History::default();
+        let doc = Rope::from("a\n");
+        let mut state = State {
+            doc,
+            selection: Selection::point(0),
+        };
+
+        fn undo(history: &mut History, state: &mut State) {
+            if let Some(transaction) = history.undo() {
+                transaction.apply(&mut state.doc);
+            }
+        }
+
+        fn earlier(history: &mut History, state: &mut State, uk: UndoKind) {
+            let txns = history.earlier(uk);
+            for txn in txns {
+                txn.apply(&mut state.doc);
+            }
+        }
+
+        fn later(history: &mut History, state: &mut State, uk: UndoKind) {
+            let txns = history.later(uk);
+            for txn in txns {
+                txn.apply(&mut state.doc);
+            }
+        }
+
+        fn commit_change(
+            history: &mut History,
+            state: &mut State,
+            change: crate::transaction::Change,
+            instant: Instant,
+        ) {
+            let txn = Transaction::change(&state.doc, vec![change].into_iter());
+            history.commit_revision_at_timestamp(&txn, state, instant);
+            txn.apply(&mut state.doc);
+        }
+
+        let t0 = Instant::now();
+        let t = |n| t0.checked_add(Duration::from_secs(n)).unwrap();
+
+        commit_change(&mut history, &mut state, (1, 1, Some(" b".into())), t(0));
+        assert_eq!("a b\n", state.doc);
+
+        commit_change(&mut history, &mut state, (3, 3, Some(" c".into())), t(10));
+        assert_eq!("a b c\n", state.doc);
+
+        commit_change(&mut history, &mut state, (5, 5, Some(" d".into())), t(20));
+        assert_eq!("a b c d\n", state.doc);
+
+        undo(&mut history, &mut state);
+        assert_eq!("a b c\n", state.doc);
+
+        commit_change(&mut history, &mut state, (5, 5, Some(" e".into())), t(30));
+        assert_eq!("a b c e\n", state.doc);
+
+        undo(&mut history, &mut state);
+        undo(&mut history, &mut state);
+        assert_eq!("a b\n", state.doc);
+
+        commit_change(&mut history, &mut state, (1, 3, None), t(40));
+        assert_eq!("a\n", state.doc);
+
+        commit_change(&mut history, &mut state, (1, 1, Some(" f".into())), t(50));
+        assert_eq!("a f\n", state.doc);
+
+        use UndoKind::*;
+
+        earlier(&mut history, &mut state, Steps(3));
+        assert_eq!("a b c d\n", state.doc);
+
+        later(&mut history, &mut state, TimePeriod(Duration::new(20, 0)));
+        assert_eq!("a\n", state.doc);
+
+        earlier(&mut history, &mut state, TimePeriod(Duration::new(19, 0)));
+        assert_eq!("a b c d\n", state.doc);
+
+        earlier(
+            &mut history,
+            &mut state,
+            TimePeriod(Duration::new(10000, 0)),
+        );
+        assert_eq!("a\n", state.doc);
+
+        later(&mut history, &mut state, Steps(50));
+        assert_eq!("a f\n", state.doc);
+
+        earlier(&mut history, &mut state, Steps(4));
+        assert_eq!("a b c\n", state.doc);
+
+        later(&mut history, &mut state, TimePeriod(Duration::new(1, 0)));
+        assert_eq!("a b c\n", state.doc);
+
+        later(&mut history, &mut state, TimePeriod(Duration::new(5, 0)));
+        assert_eq!("a b c d\n", state.doc);
+
+        later(&mut history, &mut state, TimePeriod(Duration::new(6, 0)));
+        assert_eq!("a b c e\n", state.doc);
+
+        later(&mut history, &mut state, Steps(1));
+        assert_eq!("a\n", state.doc);
+    }
+
+    #[test]
+    fn test_parse_undo_kind() {
+        use UndoKind::*;
+
+        // Default is one step.
+        assert_eq!("".parse(), Ok(Steps(1)));
+
+        // An integer means the number of steps.
+        assert_eq!("1".parse(), Ok(Steps(1)));
+        assert_eq!("  16 ".parse(), Ok(Steps(16)));
+
+        // Duration has a strict format.
+        let validation_err = Err("duration should be composed \
+         of positive integers followed by time units"
+            .to_string());
+        assert_eq!("  16 33".parse::<UndoKind>(), validation_err);
+        assert_eq!("  seconds 22  ".parse::<UndoKind>(), validation_err);
+        assert_eq!("  -4 m".parse::<UndoKind>(), validation_err);
+        assert_eq!("5s 3".parse::<UndoKind>(), validation_err);
+
+        // Units are u64.
+        assert_eq!(
+            "18446744073709551616minutes".parse::<UndoKind>(),
+            Err("integer too large: 18446744073709551616".to_string())
+        );
+
+        // Units are validated.
+        assert_eq!(
+            "1 millennium".parse::<UndoKind>(),
+            Err("incorrect time unit: millennium".to_string())
+        );
+
+        // Units can't be specified twice.
+        assert_eq!(
+            "2 seconds 6s".parse::<UndoKind>(),
+            Err("seconds specified more than once".to_string())
+        );
+
+        // Various formats are correctly handled.
+        assert_eq!(
+            "4s".parse::<UndoKind>(),
+            Ok(TimePeriod(Duration::from_secs(4)))
+        );
+        assert_eq!(
+            "2m".parse::<UndoKind>(),
+            Ok(TimePeriod(Duration::from_secs(120)))
+        );
+        assert_eq!(
+            "5h".parse::<UndoKind>(),
+            Ok(TimePeriod(Duration::from_secs(5 * 60 * 60)))
+        );
+        assert_eq!(
+            "3d".parse::<UndoKind>(),
+            Ok(TimePeriod(Duration::from_secs(3 * 24 * 60 * 60)))
+        );
+        assert_eq!(
+            "1m30s".parse::<UndoKind>(),
+            Ok(TimePeriod(Duration::from_secs(90)))
+        );
+        assert_eq!(
+            "1m 20 seconds".parse::<UndoKind>(),
+            Ok(TimePeriod(Duration::from_secs(80)))
+        );
+        assert_eq!(
+            "  2 minute 1day".parse::<UndoKind>(),
+            Ok(TimePeriod(Duration::from_secs(24 * 60 * 60 + 2 * 60)))
+        );
+        assert_eq!(
+            "3 d 2hour 5 minutes 30sec".parse::<UndoKind>(),
+            Ok(TimePeriod(Duration::from_secs(
+                3 * 24 * 60 * 60 + 2 * 60 * 60 + 5 * 60 + 30
+            )))
+        );
+
+        // Sum overflow is handled.
+        assert_eq!(
+            "18446744073709551615minutes".parse::<UndoKind>(),
+            Err("duration too large".to_string())
+        );
+        assert_eq!(
+            "1 minute 18446744073709551615 seconds".parse::<UndoKind>(),
+            Err("duration too large".to_string())
+        );
+    }
 }

helix-core/src/increment/date_time.rs

@@ -0,0 +1,320 @@
+use chrono::{Duration, NaiveDate, NaiveDateTime, NaiveTime};
+use once_cell::sync::Lazy;
+use regex::Regex;
+use std::fmt::Write;
+
+/// Increment a Date or DateTime
+///
+/// If just a Date is selected the day will be incremented.
+/// If a DateTime is selected the second will be incremented.
+pub fn increment(selected_text: &str, amount: i64) -> Option<String> {
+    if selected_text.is_empty() {
+        return None;
+    }
+
+    FORMATS.iter().find_map(|format| {
+        let captures = format.regex.captures(selected_text)?;
+        if captures.len() - 1 != format.fields.len() {
+            return None;
+        }
+
+        let date_time = captures.get(0)?;
+        let has_date = format.fields.iter().any(|f| f.unit.is_date());
+        let has_time = format.fields.iter().any(|f| f.unit.is_time());
+        let date_time = &selected_text[date_time.start()..date_time.end()];
+        match (has_date, has_time) {
+            (true, true) => {
+                let date_time = NaiveDateTime::parse_from_str(date_time, format.fmt).ok()?;
+                Some(
+                    date_time
+                        .checked_add_signed(Duration::minutes(amount))?
+                        .format(format.fmt)
+                        .to_string(),
+                )
+            }
+            (true, false) => {
+                let date = NaiveDate::parse_from_str(date_time, format.fmt).ok()?;
+                Some(
+                    date.checked_add_signed(Duration::days(amount))?
+                        .format(format.fmt)
+                        .to_string(),
+                )
+            }
+            (false, true) => {
+                let time = NaiveTime::parse_from_str(date_time, format.fmt).ok()?;
+                let (adjusted_time, _) = time.overflowing_add_signed(Duration::minutes(amount));
+                Some(adjusted_time.format(format.fmt).to_string())
+            }
+            (false, false) => None,
+        }
+    })
+}
+
+static FORMATS: Lazy<Vec<Format>> = Lazy::new(|| {
+    vec![
+        Format::new("%Y-%m-%d %H:%M:%S"), // 2021-11-24 07:12:23
+        Format::new("%Y/%m/%d %H:%M:%S"), // 2021/11/24 07:12:23
+        Format::new("%Y-%m-%d %H:%M"),    // 2021-11-24 07:12
+        Format::new("%Y/%m/%d %H:%M"),    // 2021/11/24 07:12
+        Format::new("%Y-%m-%d"),          // 2021-11-24
+        Format::new("%Y/%m/%d"),          // 2021/11/24
+        Format::new("%a %b %d %Y"),       // Wed Nov 24 2021
+        Format::new("%d-%b-%Y"),          // 24-Nov-2021
+        Format::new("%Y %b %d"),          // 2021 Nov 24
+        Format::new("%b %d, %Y"),         // Nov 24, 2021
+        Format::new("%-I:%M:%S %P"),      // 7:21:53 am
+        Format::new("%-I:%M %P"),         // 7:21 am
+        Format::new("%-I:%M:%S %p"),      // 7:21:53 AM
+        Format::new("%-I:%M %p"),         // 7:21 AM
+        Format::new("%H:%M:%S"),          // 23:24:23
+        Format::new("%H:%M"),             // 23:24
+    ]
+});
+
+#[derive(Debug)]
+struct Format {
+    fmt: &'static str,
+    fields: Vec<DateField>,
+    regex: Regex,
+    max_len: usize,
+}
+
+impl Format {
+    fn new(fmt: &'static str) -> Self {
+        let mut remaining = fmt;
+        let mut fields = Vec::new();
+        let mut regex = "^".to_string();
+        let mut max_len = 0;
+
+        while let Some(i) = remaining.find('%') {
+            let after = &remaining[i + 1..];
+            let mut chars = after.chars();
+            let c = chars.next().unwrap();
+
+            let spec_len = if c == '-' {
+                1 + chars.next().unwrap().len_utf8()
+            } else {
+                c.len_utf8()
+            };
+
+            let specifier = &after[..spec_len];
+            let field = DateField::from_specifier(specifier).unwrap();
+            fields.push(field);
+            max_len += field.max_len + remaining[..i].len();
+            regex += &remaining[..i];
+            write!(regex, "({})", field.regex).unwrap();
+            remaining = &after[spec_len..];
+        }
+        regex += "$";
+
+        let regex = Regex::new(&regex).unwrap();
+
+        Self {
+            fmt,
+            fields,
+            regex,
+            max_len,
+        }
+    }
+}
+
+impl PartialEq for Format {
+    fn eq(&self, other: &Self) -> bool {
+        self.fmt == other.fmt && self.fields == other.fields && self.max_len == other.max_len
+    }
+}
+
+impl Eq for Format {}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+struct DateField {
+    regex: &'static str,
+    unit: DateUnit,
+    max_len: usize,
+}
+
+impl DateField {
+    fn from_specifier(specifier: &str) -> Option<Self> {
+        match specifier {
+            "Y" => Some(Self {
+                regex: r"\d{4}",
+                unit: DateUnit::Years,
+                max_len: 5,
+            }),
+            "y" => Some(Self {
+                regex: r"\d\d",
+                unit: DateUnit::Years,
+                max_len: 2,
+            }),
+            "m" => Some(Self {
+                regex: r"[0-1]\d",
+                unit: DateUnit::Months,
+                max_len: 2,
+            }),
+            "d" => Some(Self {
+                regex: r"[0-3]\d",
+                unit: DateUnit::Days,
+                max_len: 2,
+            }),
+            "-d" => Some(Self {
+                regex: r"[1-3]?\d",
+                unit: DateUnit::Days,
+                max_len: 2,
+            }),
+            "a" => Some(Self {
+                regex: r"Sun|Mon|Tue|Wed|Thu|Fri|Sat",
+                unit: DateUnit::Days,
+                max_len: 3,
+            }),
+            "A" => Some(Self {
+                regex: r"Sunday|Monday|Tuesday|Wednesday|Thursday|Friday|Saturday",
+                unit: DateUnit::Days,
+                max_len: 9,
+            }),
+            "b" | "h" => Some(Self {
+                regex: r"Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec",
+                unit: DateUnit::Months,
+                max_len: 3,
+            }),
+            "B" => Some(Self {
+                regex: r"January|February|March|April|May|June|July|August|September|October|November|December",
+                unit: DateUnit::Months,
+                max_len: 9,
+            }),
+            "H" => Some(Self {
+                regex: r"[0-2]\d",
+                unit: DateUnit::Hours,
+                max_len: 2,
+            }),
+            "M" => Some(Self {
+                regex: r"[0-5]\d",
+                unit: DateUnit::Minutes,
+                max_len: 2,
+            }),
+            "S" => Some(Self {
+                regex: r"[0-5]\d",
+                unit: DateUnit::Seconds,
+                max_len: 2,
+            }),
+            "I" => Some(Self {
+                regex: r"[0-1]\d",
+                unit: DateUnit::Hours,
+                max_len: 2,
+            }),
+            "-I" => Some(Self {
+                regex: r"1?\d",
+                unit: DateUnit::Hours,
+                max_len: 2,
+            }),
+            "P" => Some(Self {
+                regex: r"am|pm",
+                unit: DateUnit::AmPm,
+                max_len: 2,
+            }),
+            "p" => Some(Self {
+                regex: r"AM|PM",
+                unit: DateUnit::AmPm,
+                max_len: 2,
+            }),
+            _ => None,
+        }
+    }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+enum DateUnit {
+    Years,
+    Months,
+    Days,
+    Hours,
+    Minutes,
+    Seconds,
+    AmPm,
+}
+
+impl DateUnit {
+    fn is_date(self) -> bool {
+        matches!(self, DateUnit::Years | DateUnit::Months | DateUnit::Days)
+    }
+
+    fn is_time(self) -> bool {
+        matches!(
+            self,
+            DateUnit::Hours | DateUnit::Minutes | DateUnit::Seconds
+        )
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_increment_date_times() {
+        let tests = [
+            // (original, cursor, amount, expected)
+            ("2020-02-28", 1, "2020-02-29"),
+            ("2020-02-29", 1, "2020-03-01"),
+            ("2020-01-31", 1, "2020-02-01"),
+            ("2020-01-20", 1, "2020-01-21"),
+            ("2021-01-01", -1, "2020-12-31"),
+            ("2021-01-31", -2, "2021-01-29"),
+            ("2020-02-28", 1, "2020-02-29"),
+            ("2021-02-28", 1, "2021-03-01"),
+            ("2021-03-01", -1, "2021-02-28"),
+            ("2020-02-29", -1, "2020-02-28"),
+            ("2020-02-20", -1, "2020-02-19"),
+            ("2021-03-01", -1, "2021-02-28"),
+            ("1980/12/21", 100, "1981/03/31"),
+            ("1980/12/21", -100, "1980/09/12"),
+            ("1980/12/21", 1000, "1983/09/17"),
+            ("1980/12/21", -1000, "1978/03/27"),
+            ("2021-11-24 07:12:23", 1, "2021-11-24 07:13:23"),
+            ("2021-11-24 07:12", 1, "2021-11-24 07:13"),
+            ("Wed Nov 24 2021", 1, "Thu Nov 25 2021"),
+            ("24-Nov-2021", 1, "25-Nov-2021"),
+            ("2021 Nov 24", 1, "2021 Nov 25"),
+            ("Nov 24, 2021", 1, "Nov 25, 2021"),
+            ("7:21:53 am", 1, "7:22:53 am"),
+            ("7:21:53 AM", 1, "7:22:53 AM"),
+            ("7:21 am", 1, "7:22 am"),
+            ("23:24:23", 1, "23:25:23"),
+            ("23:24", 1, "23:25"),
+            ("23:59", 1, "00:00"),
+            ("23:59:59", 1, "00:00:59"),
+        ];
+
+        for (original, amount, expected) in tests {
+            assert_eq!(increment(original, amount).unwrap(), expected);
+        }
+    }
+
+    #[test]
+    fn test_invalid_date_times() {
+        let tests = [
+            "0000-00-00",
+            "1980-2-21",
+            "1980-12-1",
+            "12345",
+            "2020-02-30",
+            "1999-12-32",
+            "19-12-32",
+            "1-2-3",
+            "0000/00/00",
+            "1980/2/21",
+            "1980/12/1",
+            "12345",
+            "2020/02/30",
+            "1999/12/32",
+            "19/12/32",
+            "1/2/3",
+            "123:456:789",
+            "11:61",
+            "2021-55-12 08:12:54",
+        ];
+
+        for invalid in tests {
+            assert_eq!(increment(invalid, 1), None)
+        }
+    }
+}

helix-core/src/increment/integer.rs

@@ -0,0 +1,235 @@
+const SEPARATOR: char = '_';
+
+/// Increment an integer.
+///
+/// Supported bases:
+///     2 with prefix 0b
+///     8 with prefix 0o
+///     10 with no prefix
+///     16 with prefix 0x
+///
+/// An integer can contain `_` as a separator but may not start or end with a separator.
+/// Base 10 integers can go negative, but bases 2, 8, and 16 cannot.
+/// All addition and subtraction is saturating.
+pub fn increment(selected_text: &str, amount: i64) -> Option<String> {
+    if selected_text.is_empty()
+        || selected_text.ends_with(SEPARATOR)
+        || selected_text.starts_with(SEPARATOR)
+    {
+        return None;
+    }
+
+    let radix = if selected_text.starts_with("0x") {
+        16
+    } else if selected_text.starts_with("0o") {
+        8
+    } else if selected_text.starts_with("0b") {
+        2
+    } else {
+        10
+    };
+
+    // Get separator indexes from right to left.
+    let separator_rtl_indexes: Vec<usize> = selected_text
+        .chars()
+        .rev()
+        .enumerate()
+        .filter_map(|(i, c)| if c == SEPARATOR { Some(i) } else { None })
+        .collect();
+
+    let word: String = selected_text.chars().filter(|&c| c != SEPARATOR).collect();
+
+    let mut new_text = if radix == 10 {
+        let number = &word;
+        let value = i128::from_str_radix(number, radix).ok()?;
+        let new_value = value.saturating_add(amount as i128);
+
+        let format_length = match (value.is_negative(), new_value.is_negative()) {
+            (true, false) => number.len() - 1,
+            (false, true) => number.len() + 1,
+            _ => number.len(),
+        } - separator_rtl_indexes.len();
+
+        if number.starts_with('0') || number.starts_with("-0") {
+            format!("{:01$}", new_value, format_length)
+        } else {
+            format!("{}", new_value)
+        }
+    } else {
+        let number = &word[2..];
+        let value = u128::from_str_radix(number, radix).ok()?;
+        let new_value = (value as i128).saturating_add(amount as i128);
+        let new_value = if new_value < 0 { 0 } else { new_value };
+        let format_length = selected_text.len() - 2 - separator_rtl_indexes.len();
+
+        match radix {
+            2 => format!("0b{:01$b}", new_value, format_length),
+            8 => format!("0o{:01$o}", new_value, format_length),
+            16 => {
+                let (lower_count, upper_count): (usize, usize) =
+                    number.chars().fold((0, 0), |(lower, upper), c| {
+                        (
+                            lower + c.is_ascii_lowercase() as usize,
+                            upper + c.is_ascii_uppercase() as usize,
+                        )
+                    });
+                if upper_count > lower_count {
+                    format!("0x{:01$X}", new_value, format_length)
+                } else {
+                    format!("0x{:01$x}", new_value, format_length)
+                }
+            }
+            _ => unimplemented!("radix not supported: {}", radix),
+        }
+    };
+
+    // Add separators from original number.
+    for &rtl_index in &separator_rtl_indexes {
+        if rtl_index < new_text.len() {
+            let new_index = new_text.len().saturating_sub(rtl_index);
+            if new_index > 0 {
+                new_text.insert(new_index, SEPARATOR);
+            }
+        }
+    }
+
+    // Add in additional separators if necessary.
+    if new_text.len() > selected_text.len() && !separator_rtl_indexes.is_empty() {
+        let spacing = match separator_rtl_indexes.as_slice() {
+            [.., b, a] => a - b - 1,
+            _ => separator_rtl_indexes[0],
+        };
+
+        let prefix_length = if radix == 10 { 0 } else { 2 };
+        if let Some(mut index) = new_text.find(SEPARATOR) {
+            while index - prefix_length > spacing {
+                index -= spacing;
+                new_text.insert(index, SEPARATOR);
+            }
+        }
+    }
+
+    Some(new_text)
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_increment_basic_decimal_numbers() {
+        let tests = [
+            ("100", 1, "101"),
+            ("100", -1, "99"),
+            ("99", 1, "100"),
+            ("100", 1000, "1100"),
+            ("100", -1000, "-900"),
+            ("-1", 1, "0"),
+            ("-1", 2, "1"),
+            ("1", -1, "0"),
+            ("1", -2, "-1"),
+        ];
+
+        for (original, amount, expected) in tests {
+            assert_eq!(increment(original, amount).unwrap(), expected);
+        }
+    }
+
+    #[test]
+    fn test_increment_basic_hexadecimal_numbers() {
+        let tests = [
+            ("0x0100", 1, "0x0101"),
+            ("0x0100", -1, "0x00ff"),
+            ("0x0001", -1, "0x0000"),
+            ("0x0000", -1, "0x0000"),
+            ("0xffffffffffffffff", 1, "0x10000000000000000"),
+            ("0xffffffffffffffff", 2, "0x10000000000000001"),
+            ("0xffffffffffffffff", -1, "0xfffffffffffffffe"),
+            ("0xABCDEF1234567890", 1, "0xABCDEF1234567891"),
+            ("0xabcdef1234567890", 1, "0xabcdef1234567891"),
+        ];
+
+        for (original, amount, expected) in tests {
+            assert_eq!(increment(original, amount).unwrap(), expected);
+        }
+    }
+
+    #[test]
+    fn test_increment_basic_octal_numbers() {
+        let tests = [
+            ("0o0107", 1, "0o0110"),
+            ("0o0110", -1, "0o0107"),
+            ("0o0001", -1, "0o0000"),
+            ("0o7777", 1, "0o10000"),
+            ("0o1000", -1, "0o0777"),
+            ("0o0107", 10, "0o0121"),
+            ("0o0000", -1, "0o0000"),
+            ("0o1777777777777777777777", 1, "0o2000000000000000000000"),
+            ("0o1777777777777777777777", 2, "0o2000000000000000000001"),
+            ("0o1777777777777777777777", -1, "0o1777777777777777777776"),
+        ];
+
+        for (original, amount, expected) in tests {
+            assert_eq!(increment(original, amount).unwrap(), expected);
+        }
+    }
+
+    #[test]
+    fn test_increment_basic_binary_numbers() {
+        let tests = [
+            ("0b00000100", 1, "0b00000101"),
+            ("0b00000100", -1, "0b00000011"),
+            ("0b00000100", 2, "0b00000110"),
+            ("0b00000100", -2, "0b00000010"),
+            ("0b00000001", -1, "0b00000000"),
+            ("0b00111111", 10, "0b01001001"),
+            ("0b11111111", 1, "0b100000000"),
+            ("0b10000000", -1, "0b01111111"),
+            ("0b0000", -1, "0b0000"),
+            (
+                "0b1111111111111111111111111111111111111111111111111111111111111111",
+                1,
+                "0b10000000000000000000000000000000000000000000000000000000000000000",
+            ),
+            (
+                "0b1111111111111111111111111111111111111111111111111111111111111111",
+                2,
+                "0b10000000000000000000000000000000000000000000000000000000000000001",
+            ),
+            (
+                "0b1111111111111111111111111111111111111111111111111111111111111111",
+                -1,
+                "0b1111111111111111111111111111111111111111111111111111111111111110",
+            ),
+        ];
+
+        for (original, amount, expected) in tests {
+            assert_eq!(increment(original, amount).unwrap(), expected);
+        }
+    }
+
+    #[test]
+    fn test_increment_with_separators() {
+        let tests = [
+            ("999_999", 1, "1_000_000"),
+            ("1_000_000", -1, "999_999"),
+            ("-999_999", -1, "-1_000_000"),
+            ("0x0000_0000_0001", 0x1_ffff_0000, "0x0001_ffff_0001"),
+            ("0x0000_0000", -1, "0x0000_0000"),
+            ("0x0000_0000_0000", -1, "0x0000_0000_0000"),
+            ("0b01111111_11111111", 1, "0b10000000_00000000"),
+            ("0b11111111_11111111", 1, "0b1_00000000_00000000"),
+        ];
+
+        for (original, amount, expected) in tests {
+            assert_eq!(increment(original, amount).unwrap(), expected);
+        }
+    }
+
+    #[test]
+    fn test_leading_and_trailing_separators_arent_a_match() {
+        assert_eq!(increment("9_", 1), None);
+        assert_eq!(increment("_9", 1), None);
+        assert_eq!(increment("_9_", 1), None);
+    }
+}

helix-core/src/increment/mod.rs

@@ -0,0 +1,10 @@
+mod date_time;
+mod integer;
+
+pub fn integer(selected_text: &str, amount: i64) -> Option<String> {
+    integer::increment(selected_text, amount)
+}
+
+pub fn date_time(selected_text: &str, amount: i64) -> Option<String> {
+    date_time::increment(selected_text, amount)
+}

helix-core/src/lib.rs

@@ -1,84 +1,72 @@
-#![allow(unused)]
+pub use encoding_rs as encoding;
+
 pub mod auto_pairs;
+pub mod chars;
 pub mod comment;
+pub mod config;
 pub mod diagnostic;
+pub mod diff;
+pub mod doc_formatter;
+pub mod fuzzy;
 pub mod graphemes;
-mod history;
+pub mod history;
+pub mod increment;
 pub mod indent;
+pub mod line_ending;
 pub mod macros;
 pub mod match_brackets;
 pub mod movement;
 pub mod object;
+pub mod path;
 mod position;
-pub mod register;
 pub mod search;
 pub mod selection;
-pub mod state;
+pub mod shellwords;
+pub mod surround;
 pub mod syntax;
+pub mod test;
+pub mod text_annotations;
+pub mod textobject;
 mod transaction;
+pub mod wrap;
 
-pub(crate) fn find_first_non_whitespace_char2(line: RopeSlice) -> Option<usize> {
-    // find first non-whitespace char
-    for (start, ch) in line.chars().enumerate() {
-        // TODO: could use memchr with chunks?
-        if ch != ' ' && ch != '\t' && ch != '\n' {
-            return Some(start);
-        }
-    }
-
-    None
-}
-pub(crate) fn find_first_non_whitespace_char(text: RopeSlice, line_num: usize) -> Option<usize> {
-    let line = text.line(line_num);
-    let mut start = text.line_to_char(line_num);
-
-    // find first non-whitespace char
-    for ch in line.chars() {
-        // TODO: could use memchr with chunks?
-        if ch != ' ' && ch != '\t' && ch != '\n' {
-            return Some(start);
-        }
-        start += 1;
-    }
-
-    None
+pub mod unicode {
+    pub use unicode_general_category as category;
+    pub use unicode_segmentation as segmentation;
+    pub use unicode_width as width;
 }
 
-pub fn runtime_dir() -> std::path::PathBuf {
-    // runtime env var || dir where binary is located
-    std::env::var("HELIX_RUNTIME")
-        .map(|path| path.into())
-        .unwrap_or_else(|_| {
-            std::env::current_exe()
-                .ok()
-                .and_then(|path| path.parent().map(|path| path.to_path_buf()))
-                .unwrap()
-        })
+pub use helix_loader::find_workspace;
+
+pub fn find_first_non_whitespace_char(line: RopeSlice) -> Option<usize> {
+    line.chars().position(|ch| !ch.is_whitespace())
 }
+mod rope_reader;
 
-pub fn config_dir() -> std::path::PathBuf {
-    // TODO: allow env var override
-    use etcetera::base_strategy::{choose_base_strategy, BaseStrategy};
-    let strategy = choose_base_strategy().expect("Unable to find the config directory!");
-    let mut path = strategy.config_dir();
-    path.push("helix");
-    path
-}
+pub use rope_reader::RopeReader;
+pub use ropey::{self, str_utils, Rope, RopeBuilder, RopeSlice};
 
-pub use ropey::{Rope, RopeSlice};
+// pub use tendril::StrTendril as Tendril;
+pub use smartstring::SmartString;
 
-pub use tendril::StrTendril as Tendril;
+pub type Tendril = SmartString<smartstring::LazyCompact>;
 
 #[doc(inline)]
 pub use {regex, tree_sitter};
 
-pub use position::{coords_at_pos, pos_at_coords, Position};
+pub use graphemes::RopeGraphemes;
+pub use position::{
+    char_idx_at_visual_offset, coords_at_pos, pos_at_coords, visual_offset_from_anchor,
+    visual_offset_from_block, Position, VisualOffsetError,
+};
+#[allow(deprecated)]
+pub use position::{pos_at_visual_coords, visual_coords_at_pos};
+
 pub use selection::{Range, Selection};
-pub use smallvec::SmallVec;
+pub use smallvec::{smallvec, SmallVec};
 pub use syntax::Syntax;
 
 pub use diagnostic::Diagnostic;
-pub use history::History;
-pub use state::State;
 
-pub use transaction::{Assoc, Change, ChangeSet, Operation, Transaction};
+pub use line_ending::{LineEnding, NATIVE_LINE_ENDING};
+pub use transaction::{Assoc, Change, ChangeSet, Deletion, Operation, Transaction};

helix-core/src/line_ending.rs

@@ -0,0 +1,328 @@
+use crate::{Rope, RopeSlice};
+
+#[cfg(target_os = "windows")]
+pub const NATIVE_LINE_ENDING: LineEnding = LineEnding::Crlf;
+#[cfg(not(target_os = "windows"))]
+pub const NATIVE_LINE_ENDING: LineEnding = LineEnding::LF;
+
+/// Represents one of the valid Unicode line endings.
+#[derive(PartialEq, Eq, Copy, Clone, Debug)]
+pub enum LineEnding {
+    Crlf, // CarriageReturn followed by LineFeed
+    LF,   // U+000A -- LineFeed
+    #[cfg(feature = "unicode-lines")]
+    VT, // U+000B -- VerticalTab
+    #[cfg(feature = "unicode-lines")]
+    FF, // U+000C -- FormFeed
+    #[cfg(feature = "unicode-lines")]
+    CR, // U+000D -- CarriageReturn
+    #[cfg(feature = "unicode-lines")]
+    Nel, // U+0085 -- NextLine
+    #[cfg(feature = "unicode-lines")]
+    LS, // U+2028 -- Line Separator
+    #[cfg(feature = "unicode-lines")]
+    PS, // U+2029 -- ParagraphSeparator
+}
+
+impl LineEnding {
+    #[inline]
+    pub const fn len_chars(&self) -> usize {
+        match self {
+            Self::Crlf => 2,
+            _ => 1,
+        }
+    }
+
+    #[inline]
+    pub const fn as_str(&self) -> &'static str {
+        match self {
+            Self::Crlf => "\u{000D}\u{000A}",
+            Self::LF => "\u{000A}",
+            #[cfg(feature = "unicode-lines")]
+            Self::VT => "\u{000B}",
+            #[cfg(feature = "unicode-lines")]
+            Self::FF => "\u{000C}",
+            #[cfg(feature = "unicode-lines")]
+            Self::CR => "\u{000D}",
+            #[cfg(feature = "unicode-lines")]
+            Self::Nel => "\u{0085}",
+            #[cfg(feature = "unicode-lines")]
+            Self::LS => "\u{2028}",
+            #[cfg(feature = "unicode-lines")]
+            Self::PS => "\u{2029}",
+        }
+    }
+
+    #[inline]
+    pub const fn from_char(ch: char) -> Option<LineEnding> {
+        match ch {
+            '\u{000A}' => Some(LineEnding::LF),
+            #[cfg(feature = "unicode-lines")]
+            '\u{000B}' => Some(LineEnding::VT),
+            #[cfg(feature = "unicode-lines")]
+            '\u{000C}' => Some(LineEnding::FF),
+            #[cfg(feature = "unicode-lines")]
+            '\u{000D}' => Some(LineEnding::CR),
+            #[cfg(feature = "unicode-lines")]
+            '\u{0085}' => Some(LineEnding::Nel),
+            #[cfg(feature = "unicode-lines")]
+            '\u{2028}' => Some(LineEnding::LS),
+            #[cfg(feature = "unicode-lines")]
+            '\u{2029}' => Some(LineEnding::PS),
+            // Not a line ending
+            _ => None,
+        }
+    }
+
+    // Normally we'd want to implement the FromStr trait, but in this case
+    // that would force us into a different return type than from_char or
+    // or from_rope_slice, which would be weird.
+    #[allow(clippy::should_implement_trait)]
+    #[inline]
+    pub fn from_str(g: &str) -> Option<LineEnding> {
+        match g {
+            "\u{000D}\u{000A}" => Some(LineEnding::Crlf),
+            "\u{000A}" => Some(LineEnding::LF),
+            #[cfg(feature = "unicode-lines")]
+            "\u{000B}" => Some(LineEnding::VT),
+            #[cfg(feature = "unicode-lines")]
+            "\u{000C}" => Some(LineEnding::FF),
+            #[cfg(feature = "unicode-lines")]
+            "\u{000D}" => Some(LineEnding::CR),
+            #[cfg(feature = "unicode-lines")]
+            "\u{0085}" => Some(LineEnding::Nel),
+            #[cfg(feature = "unicode-lines")]
+            "\u{2028}" => Some(LineEnding::LS),
+            #[cfg(feature = "unicode-lines")]
+            "\u{2029}" => Some(LineEnding::PS),
+            // Not a line ending
+            _ => None,
+        }
+    }
+
+    #[inline]
+    pub fn from_rope_slice(g: &RopeSlice) -> Option<LineEnding> {
+        if let Some(text) = g.as_str() {
+            LineEnding::from_str(text)
+        } else {
+            // Non-contiguous, so it can't be a line ending.
+            // Specifically, Ropey guarantees that CRLF is always
+            // contiguous.  And the remaining line endings are all
+            // single `char`s, and therefore trivially contiguous.
+            None
+        }
+    }
+}
+
+#[inline]
+pub fn str_is_line_ending(s: &str) -> bool {
+    LineEnding::from_str(s).is_some()
+}
+
+#[inline]
+pub fn rope_is_line_ending(r: RopeSlice) -> bool {
+    r.chunks().all(str_is_line_ending)
+}
+
+/// Attempts to detect what line ending the passed document uses.
+pub fn auto_detect_line_ending(doc: &Rope) -> Option<LineEnding> {
+    // Return first matched line ending. Not all possible line endings
+    // are being matched, as they might be special-use only
+    for line in doc.lines().take(100) {
+        match get_line_ending(&line) {
+            None => {}
+            #[cfg(feature = "unicode-lines")]
+            Some(LineEnding::VT) | Some(LineEnding::FF) | Some(LineEnding::PS) => {}
+            ending => return ending,
+        }
+    }
+    None
+}
+
+/// Returns the passed line's line ending, if any.
+pub fn get_line_ending(line: &RopeSlice) -> Option<LineEnding> {
+    // Last character as str.
+    let g1 = line
+        .slice(line.len_chars().saturating_sub(1)..)
+        .as_str()
+        .unwrap();
+
+    // Last two characters as str, or empty str if they're not contiguous.
+    // It's fine to punt on the non-contiguous case, because Ropey guarantees
+    // that CRLF is always contiguous.
+    let g2 = line
+        .slice(line.len_chars().saturating_sub(2)..)
+        .as_str()
+        .unwrap_or("");
+
+    // First check the two-character case for CRLF, then check the single-character case.
+    LineEnding::from_str(g2).or_else(|| LineEnding::from_str(g1))
+}
+
+#[cfg(not(feature = "unicode-lines"))]
+/// Returns the passed line's line ending, if any.
+pub fn get_line_ending_of_str(line: &str) -> Option<LineEnding> {
+    if line.ends_with("\u{000D}\u{000A}") {
+        Some(LineEnding::Crlf)
+    } else if line.ends_with('\u{000A}') {
+        Some(LineEnding::LF)
+    } else {
+        None
+    }
+}
+
+#[cfg(feature = "unicode-lines")]
+/// Returns the passed line's line ending, if any.
+pub fn get_line_ending_of_str(line: &str) -> Option<LineEnding> {
+    if line.ends_with("\u{000D}\u{000A}") {
+        Some(LineEnding::Crlf)
+    } else if line.ends_with('\u{000A}') {
+        Some(LineEnding::LF)
+    } else if line.ends_with('\u{000B}') {
+        Some(LineEnding::VT)
+    } else if line.ends_with('\u{000C}') {
+        Some(LineEnding::FF)
+    } else if line.ends_with('\u{000D}') {
+        Some(LineEnding::CR)
+    } else if line.ends_with('\u{0085}') {
+        Some(LineEnding::Nel)
+    } else if line.ends_with('\u{2028}') {
+        Some(LineEnding::LS)
+    } else if line.ends_with('\u{2029}') {
+        Some(LineEnding::PS)
+    } else {
+        None
+    }
+}
+
+/// Returns the char index of the end of the given line, not including its line ending.
+pub fn line_end_char_index(slice: &RopeSlice, line: usize) -> usize {
+    slice.line_to_char(line + 1)
+        - get_line_ending(&slice.line(line))
+            .map(|le| le.len_chars())
+            .unwrap_or(0)
+}
+
+pub fn line_end_byte_index(slice: &RopeSlice, line: usize) -> usize {
+    slice.line_to_byte(line + 1)
+        - get_line_ending(&slice.line(line))
+            .map(|le| le.as_str().len())
+            .unwrap_or(0)
+}
+
+/// Fetches line `line_idx` from the passed rope slice, sans any line ending.
+pub fn line_without_line_ending<'a>(slice: &'a RopeSlice, line_idx: usize) -> RopeSlice<'a> {
+    let start = slice.line_to_char(line_idx);
+    let end = line_end_char_index(slice, line_idx);
+    slice.slice(start..end)
+}
+
+/// Returns the char index of the end of the given RopeSlice, not including
+/// any final line ending.
+pub fn rope_end_without_line_ending(slice: &RopeSlice) -> usize {
+    slice.len_chars() - get_line_ending(slice).map(|le| le.len_chars()).unwrap_or(0)
+}
+
+#[cfg(test)]
+mod line_ending_tests {
+    use super::*;
+
+    #[test]
+    fn line_ending_autodetect() {
+        assert_eq!(
+            auto_detect_line_ending(&Rope::from_str("\n")),
+            Some(LineEnding::LF)
+        );
+        assert_eq!(
+            auto_detect_line_ending(&Rope::from_str("\r\n")),
+            Some(LineEnding::Crlf)
+        );
+        assert_eq!(auto_detect_line_ending(&Rope::from_str("hello")), None);
+        assert_eq!(auto_detect_line_ending(&Rope::from_str("")), None);
+        assert_eq!(
+            auto_detect_line_ending(&Rope::from_str("hello\nhelix\r\n")),
+            Some(LineEnding::LF)
+        );
+        assert_eq!(
+            auto_detect_line_ending(&Rope::from_str("a formfeed\u{000C}")),
+            None
+        );
+        assert_eq!(
+            auto_detect_line_ending(&Rope::from_str("\n\u{000A}\n \u{000A}")),
+            Some(LineEnding::LF)
+        );
+        assert_eq!(
+            auto_detect_line_ending(&Rope::from_str(
+                "a formfeed\u{000C} with a\u{000C} linefeed\u{000A}"
+            )),
+            Some(LineEnding::LF)
+        );
+        assert_eq!(auto_detect_line_ending(&Rope::from_str("a formfeed\u{000C} with a\u{000C} carriage return linefeed\u{000D}\u{000A} and a linefeed\u{000A}")), Some(LineEnding::Crlf));
+    }
+
+    #[test]
+    fn str_to_line_ending() {
+        #[cfg(feature = "unicode-lines")]
+        assert_eq!(LineEnding::from_str("\r"), Some(LineEnding::CR));
+        assert_eq!(LineEnding::from_str("\n"), Some(LineEnding::LF));
+        assert_eq!(LineEnding::from_str("\r\n"), Some(LineEnding::Crlf));
+        assert_eq!(LineEnding::from_str("hello\n"), None);
+    }
+
+    #[test]
+    fn rope_slice_to_line_ending() {
+        let r = Rope::from_str("hello\r\n");
+        #[cfg(feature = "unicode-lines")]
+        assert_eq!(
+            LineEnding::from_rope_slice(&r.slice(5..6)),
+            Some(LineEnding::CR)
+        );
+        assert_eq!(
+            LineEnding::from_rope_slice(&r.slice(6..7)),
+            Some(LineEnding::LF)
+        );
+        assert_eq!(
+            LineEnding::from_rope_slice(&r.slice(5..7)),
+            Some(LineEnding::Crlf)
+        );
+        assert_eq!(LineEnding::from_rope_slice(&r.slice(..)), None);
+    }
+
+    #[test]
+    fn get_line_ending_rope_slice() {
+        let r = Rope::from_str("Hello\rworld\nhow\r\nare you?");
+        #[cfg(feature = "unicode-lines")]
+        assert_eq!(get_line_ending(&r.slice(..6)), Some(LineEnding::CR));
+        assert_eq!(get_line_ending(&r.slice(..12)), Some(LineEnding::LF));
+        assert_eq!(get_line_ending(&r.slice(..17)), Some(LineEnding::Crlf));
+        assert_eq!(get_line_ending(&r.slice(..)), None);
+    }
+
+    #[test]
+    fn get_line_ending_str() {
+        let text = "Hello\rworld\nhow\r\nare you?";
+        #[cfg(feature = "unicode-lines")]
+        assert_eq!(get_line_ending_of_str(&text[..6]), Some(LineEnding::CR));
+        assert_eq!(get_line_ending_of_str(&text[..12]), Some(LineEnding::LF));
+        assert_eq!(get_line_ending_of_str(&text[..17]), Some(LineEnding::Crlf));
+        assert_eq!(get_line_ending_of_str(text), None);
+    }
+
+    #[test]
+    fn line_end_char_index_rope_slice() {
+        let r = Rope::from_str("Hello\rworld\nhow\r\nare you?");
+        let s = &r.slice(..);
+        #[cfg(not(feature = "unicode-lines"))]
+        {
+            assert_eq!(line_end_char_index(s, 0), 11);
+            assert_eq!(line_end_char_index(s, 1), 15);
+            assert_eq!(line_end_char_index(s, 2), 25);
+        }
+        #[cfg(feature = "unicode-lines")]
+        {
+            assert_eq!(line_end_char_index(s, 0), 5);
+            assert_eq!(line_end_char_index(s, 1), 11);
+            assert_eq!(line_end_char_index(s, 2), 15);
+        }
+    }
+}

helix-core/src/match_brackets.rs

@@ -1,35 +1,295 @@
-use crate::{Range, Rope, Selection, Syntax};
+use std::iter;
 
-// const PAIRS: &[(char, char)] = &[('(', ')'), ('{', '}'), ('[', ']')];
-// limit matching pairs to only ( ) { } [ ] < >
+use ropey::RopeSlice;
+use tree_sitter::Node;
 
+use crate::movement::Direction::{self, Backward, Forward};
+use crate::Syntax;
+
+const MAX_PLAINTEXT_SCAN: usize = 10000;
+const MATCH_LIMIT: usize = 16;
+
+// Limit matching pairs to only ( ) { } [ ] < > ' ' " "
+const PAIRS: &[(char, char)] = &[
+    ('(', ')'),
+    ('{', '}'),
+    ('[', ']'),
+    ('<', '>'),
+    ('\'', '\''),
+    ('\"', '\"'),
+];
+
+/// Returns the position of the matching bracket under cursor.
+///
+/// If the cursor is on the opening bracket, the position of
+/// the closing bracket is returned. If the cursor on the closing
+/// bracket, the position of the opening bracket is returned.
+///
+/// If the cursor is not on a bracket, `None` is returned.
+///
+/// If no matching bracket is found, `None` is returned.
 #[must_use]
-pub fn find(syntax: &Syntax, doc: &Rope, pos: usize) -> Option<usize> {
+pub fn find_matching_bracket(syntax: &Syntax, doc: RopeSlice, pos: usize) -> Option<usize> {
+    if pos >= doc.len_chars() || !is_valid_bracket(doc.char(pos)) {
+        return None;
+    }
+    find_pair(syntax, doc, pos, false)
+}
+
+// Returns the position of the bracket that is closing the current scope.
+//
+// If the cursor is on an opening or closing bracket, the function
+// behaves equivalent to [`find_matching_bracket`].
+//
+// If the cursor position is within a scope, the function searches
+// for the surrounding scope that is surrounded by brackets and
+// returns the position of the closing bracket for that scope.
+//
+// If no surrounding scope is found, the function returns `None`.
+#[must_use]
+pub fn find_matching_bracket_fuzzy(syntax: &Syntax, doc: RopeSlice, pos: usize) -> Option<usize> {
+    find_pair(syntax, doc, pos, true)
+}
+
+fn find_pair(
+    syntax: &Syntax,
+    doc: RopeSlice,
+    pos_: usize,
+    traverse_parents: bool,
+) -> Option<usize> {
     let tree = syntax.tree();
+    let pos = doc.char_to_byte(pos_);
 
-    let byte_pos = doc.char_to_byte(pos);
+    let mut node = tree.root_node().descendant_for_byte_range(pos, pos)?;
 
-    // most naive implementation: find the innermost syntax node, if we're at the edge of a node,
-    // return the other edge.
+    loop {
+        if node.is_named() {
+            let (start_byte, end_byte) = surrounding_bytes(doc, &node)?;
+            let (start_char, end_char) = (doc.byte_to_char(start_byte), doc.byte_to_char(end_byte));
 
-    let mut node = match tree
-        .root_node()
-        .named_descendant_for_byte_range(byte_pos, byte_pos)
-    {
-        Some(node) => node,
-        None => return None,
-    };
+            if is_valid_pair(doc, start_char, end_char) {
+                if end_byte == pos {
+                    return Some(start_char);
+                }
 
-    let start_byte = node.start_byte();
-    let end_byte = node.end_byte() - 1; // it's end exclusive
+                // We return the end char if the cursor is either on the start char
+                // or at some arbitrary position between start and end char.
+                if traverse_parents || start_byte == pos {
+                    return Some(end_char);
+                }
+            }
+        }
+        // this node itselt wasn't a pair but maybe its siblings are
 
-    if start_byte == byte_pos {
-        return Some(doc.byte_to_char(end_byte));
+        // check if we are *on* the pair (special cased so we don't look
+        // at the current node twice and to jump to the start on that case)
+        if let Some(open) = as_close_pair(doc, &node) {
+            if let Some(pair_start) = find_pair_end(doc, node.prev_sibling(), open, Backward) {
+                return Some(pair_start);
+            }
+        }
+
+        if !traverse_parents {
+            // check if we are *on* the opening pair (special cased here as
+            // an opptimization since we only care about bracket on the cursor
+            // here)
+            if let Some(close) = as_open_pair(doc, &node) {
+                if let Some(pair_end) = find_pair_end(doc, node.next_sibling(), close, Forward) {
+                    return Some(pair_end);
+                }
+            }
+            if node.is_named() {
+                break;
+            }
+        }
+
+        for close in
+            iter::successors(node.next_sibling(), |node| node.next_sibling()).take(MATCH_LIMIT)
+        {
+            let Some(open) = as_close_pair(doc, &close) else {
+                continue;
+            };
+            if find_pair_end(doc, Some(node), open, Backward).is_some() {
+                return doc.try_byte_to_char(close.start_byte()).ok();
+            }
+        }
+        let Some(parent) = node.parent() else {
+            break;
+        };
+        node = parent;
+    }
+    let node = tree.root_node().named_descendant_for_byte_range(pos, pos)?;
+    if node.child_count() != 0 {
+        return None;
+    }
+    let node_start = doc.byte_to_char(node.start_byte());
+    find_matching_bracket_plaintext(doc.byte_slice(node.byte_range()), pos_ - node_start)
+        .map(|pos| pos + node_start)
+}
+
+/// Returns the position of the matching bracket under cursor.
+/// This function works on plain text and ignores tree-sitter grammar.
+/// The search is limited to `MAX_PLAINTEXT_SCAN` characters
+///
+/// If the cursor is on the opening bracket, the position of
+/// the closing bracket is returned. If the cursor on the closing
+/// bracket, the position of the opening bracket is returned.
+///
+/// If the cursor is not on a bracket, `None` is returned.
+///
+/// If no matching bracket is found, `None` is returned.
+#[must_use]
+pub fn find_matching_bracket_plaintext(doc: RopeSlice, cursor_pos: usize) -> Option<usize> {
+    // Don't do anything when the cursor is not on top of a bracket.
+    let bracket = doc.char(cursor_pos);
+    if !is_valid_bracket(bracket) {
+        return None;
     }
 
-    if end_byte == byte_pos {
-        return Some(doc.byte_to_char(start_byte));
+    // Determine the direction of the matching.
+    let is_fwd = is_forward_bracket(bracket);
+    let chars_iter = if is_fwd {
+        doc.chars_at(cursor_pos + 1)
+    } else {
+        doc.chars_at(cursor_pos).reversed()
+    };
+
+    let mut open_cnt = 1;
+
+    for (i, candidate) in chars_iter.take(MAX_PLAINTEXT_SCAN).enumerate() {
+        if candidate == bracket {
+            open_cnt += 1;
+        } else if is_valid_pair(
+            doc,
+            if is_fwd {
+                cursor_pos
+            } else {
+                cursor_pos - i - 1
+            },
+            if is_fwd {
+                cursor_pos + i + 1
+            } else {
+                cursor_pos
+            },
+        ) {
+            // Return when all pending brackets have been closed.
+            if open_cnt == 1 {
+                return Some(if is_fwd {
+                    cursor_pos + i + 1
+                } else {
+                    cursor_pos - i - 1
+                });
+            }
+            open_cnt -= 1;
+        }
     }
 
     None
 }
+
+fn is_valid_bracket(c: char) -> bool {
+    PAIRS.iter().any(|(l, r)| *l == c || *r == c)
+}
+
+fn is_forward_bracket(c: char) -> bool {
+    PAIRS.iter().any(|(l, _)| *l == c)
+}
+
+fn is_valid_pair(doc: RopeSlice, start_char: usize, end_char: usize) -> bool {
+    PAIRS.contains(&(doc.char(start_char), doc.char(end_char)))
+}
+
+fn surrounding_bytes(doc: RopeSlice, node: &Node) -> Option<(usize, usize)> {
+    let len = doc.len_bytes();
+
+    let start_byte = node.start_byte();
+    let end_byte = node.end_byte().saturating_sub(1);
+
+    if start_byte >= len || end_byte >= len {
+        return None;
+    }
+
+    Some((start_byte, end_byte))
+}
+
+/// Tests if this node is a pair close char and returns the expected open char
+fn as_close_pair(doc: RopeSlice, node: &Node) -> Option<char> {
+    let close = as_char(doc, node)?.1;
+    PAIRS
+        .iter()
+        .find_map(|&(open, close_)| (close_ == close).then_some(open))
+}
+
+/// Checks if `node` or its siblings (at most MATCH_LIMIT nodes) is the specified closing char
+///
+/// # Returns
+///
+/// The position of the found node or `None` otherwise
+fn find_pair_end(
+    doc: RopeSlice,
+    node: Option<Node>,
+    end_char: char,
+    direction: Direction,
+) -> Option<usize> {
+    let advance = match direction {
+        Forward => Node::next_sibling,
+        Backward => Node::prev_sibling,
+    };
+    iter::successors(node, advance)
+        .take(MATCH_LIMIT)
+        .find_map(|node| {
+            let (pos, c) = as_char(doc, &node)?;
+            (end_char == c).then_some(pos)
+        })
+}
+
+/// Tests if this node is a pair close char and returns the expected open char
+fn as_open_pair(doc: RopeSlice, node: &Node) -> Option<char> {
+    let open = as_char(doc, node)?.1;
+    PAIRS
+        .iter()
+        .find_map(|&(open_, close)| (open_ == open).then_some(close))
+}
+
+/// If node is a single char return it (and its char position)
+fn as_char(doc: RopeSlice, node: &Node) -> Option<(usize, char)> {
+    // TODO: multi char/non ASCII pairs
+    if node.byte_range().len() != 1 {
+        return None;
+    }
+    let pos = doc.try_byte_to_char(node.start_byte()).ok()?;
+    Some((pos, doc.char(pos)))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_find_matching_bracket_current_line_plaintext() {
+        let assert = |input: &str, pos, expected| {
+            let input = RopeSlice::from(input);
+            let actual = find_matching_bracket_plaintext(input, pos);
+            assert_eq!(expected, actual.unwrap());
+
+            let actual = find_matching_bracket_plaintext(input, expected);
+            assert_eq!(pos, actual.unwrap(), "expected symmetrical behaviour");
+        };
+
+        assert("(hello)", 0, 6);
+        assert("((hello))", 0, 8);
+        assert("((hello))", 1, 7);
+        assert("(((hello)))", 2, 8);
+
+        assert("key: ${value}", 6, 12);
+        assert("key: ${value} # (some comment)", 16, 29);
+
+        assert("(paren (paren {bracket}))", 0, 24);
+        assert("(paren (paren {bracket}))", 7, 23);
+        assert("(paren (paren {bracket}))", 14, 22);
+
+        assert("(prev line\n ) (middle) ( \n next line)", 0, 12);
+        assert("(prev line\n ) (middle) ( \n next line)", 14, 21);
+        assert("(prev line\n ) (middle) ( \n next line)", 23, 36);
+    }
+}

helix-core/src/object.rs

@@ -1,27 +1,71 @@
 use crate::{Range, RopeSlice, Selection, Syntax};
-use smallvec::smallvec;
+use tree_sitter::Node;
 
-// TODO: to contract_selection we'd need to store the previous ranges before expand.
-// Maybe just contract to the first child node?
-pub fn expand_selection(syntax: &Syntax, text: RopeSlice, selection: &Selection) -> Selection {
+pub fn expand_selection(syntax: &Syntax, text: RopeSlice, selection: Selection) -> Selection {
+    select_node_impl(syntax, text, selection, |mut node, from, to| {
+        while node.start_byte() == from && node.end_byte() == to {
+            node = node.parent()?;
+        }
+        Some(node)
+    })
+}
+
+pub fn shrink_selection(syntax: &Syntax, text: RopeSlice, selection: Selection) -> Selection {
+    select_node_impl(syntax, text, selection, |descendant, _from, _to| {
+        descendant.child(0).or(Some(descendant))
+    })
+}
+
+pub fn select_sibling<F>(
+    syntax: &Syntax,
+    text: RopeSlice,
+    selection: Selection,
+    sibling_fn: &F,
+) -> Selection
+where
+    F: Fn(Node) -> Option<Node>,
+{
+    select_node_impl(syntax, text, selection, |descendant, _from, _to| {
+        find_sibling_recursive(descendant, sibling_fn)
+    })
+}
+
+fn find_sibling_recursive<F>(node: Node, sibling_fn: F) -> Option<Node>
+where
+    F: Fn(Node) -> Option<Node>,
+{
+    sibling_fn(node).or_else(|| {
+        node.parent()
+            .and_then(|node| find_sibling_recursive(node, sibling_fn))
+    })
+}
+
+fn select_node_impl<F>(
+    syntax: &Syntax,
+    text: RopeSlice,
+    selection: Selection,
+    select_fn: F,
+) -> Selection
+where
+    F: Fn(Node, usize, usize) -> Option<Node>,
+{
     let tree = syntax.tree();
 
     selection.transform(|range| {
         let from = text.char_to_byte(range.from());
         let to = text.char_to_byte(range.to());
 
-        // find parent of a descendant that matches the range
-        let parent = match tree
+        let node = match tree
             .root_node()
             .descendant_for_byte_range(from, to)
-            .and_then(|node| node.parent())
+            .and_then(|node| select_fn(node, from, to))
         {
-            Some(parent) => parent,
+            Some(node) => node,
             None => return range,
         };
 
-        let from = text.byte_to_char(parent.start_byte());
-        let to = text.byte_to_char(parent.end_byte());
+        let from = text.byte_to_char(node.start_byte());
+        let to = text.byte_to_char(node.end_byte());
 
         if range.head < range.anchor {
             Range::new(to, from)

helix-core/src/path.rs

@@ -0,0 +1,162 @@
+use etcetera::home_dir;
+use std::path::{Component, Path, PathBuf};
+
+/// Replaces users home directory from `path` with tilde `~` if the directory
+/// is available, otherwise returns the path unchanged.
+pub fn fold_home_dir(path: &Path) -> PathBuf {
+    if let Ok(home) = home_dir() {
+        if let Ok(stripped) = path.strip_prefix(&home) {
+            return PathBuf::from("~").join(stripped);
+        }
+    }
+
+    path.to_path_buf()
+}
+
+/// Expands tilde `~` into users home directory if available, otherwise returns the path
+/// unchanged. The tilde will only be expanded when present as the first component of the path
+/// and only slash follows it.
+pub fn expand_tilde(path: &Path) -> PathBuf {
+    let mut components = path.components().peekable();
+    if let Some(Component::Normal(c)) = components.peek() {
+        if c == &"~" {
+            if let Ok(home) = home_dir() {
+                // it's ok to unwrap, the path starts with `~`
+                return home.join(path.strip_prefix("~").unwrap());
+            }
+        }
+    }
+
+    path.to_path_buf()
+}
+
+/// Normalize a path, removing things like `.` and `..`.
+///
+/// CAUTION: This does not resolve symlinks (unlike
+/// [`std::fs::canonicalize`]). This may cause incorrect or surprising
+/// behavior at times. This should be used carefully. Unfortunately,
+/// [`std::fs::canonicalize`] can be hard to use correctly, since it can often
+/// fail, or on Windows returns annoying device paths. This is a problem Cargo
+/// needs to improve on.
+/// Copied from cargo: <https://github.com/rust-lang/cargo/blob/070e459c2d8b79c5b2ac5218064e7603329c92ae/crates/cargo-util/src/paths.rs#L81>
+pub fn get_normalized_path(path: &Path) -> PathBuf {
+    // normalization strategy is to canonicalize first ancestor path that exists (i.e., canonicalize as much as possible),
+    // then run handrolled normalization on the non-existent remainder
+    let (base, path) = path
+        .ancestors()
+        .find_map(|base| {
+            let canonicalized_base = dunce::canonicalize(base).ok()?;
+            let remainder = path.strip_prefix(base).ok()?.into();
+            Some((canonicalized_base, remainder))
+        })
+        .unwrap_or_else(|| (PathBuf::new(), PathBuf::from(path)));
+
+    if path.as_os_str().is_empty() {
+        return base;
+    }
+
+    let mut components = path.components().peekable();
+    let mut ret = if let Some(c @ Component::Prefix(..)) = components.peek().cloned() {
+        components.next();
+        PathBuf::from(c.as_os_str())
+    } else {
+        PathBuf::new()
+    };
+
+    for component in components {
+        match component {
+            Component::Prefix(..) => unreachable!(),
+            Component::RootDir => {
+                ret.push(component.as_os_str());
+            }
+            Component::CurDir => {}
+            Component::ParentDir => {
+                ret.pop();
+            }
+            Component::Normal(c) => {
+                ret.push(c);
+            }
+        }
+    }
+    base.join(ret)
+}
+
+/// Returns the canonical, absolute form of a path with all intermediate components normalized.
+///
+/// This function is used instead of `std::fs::canonicalize` because we don't want to verify
+/// here if the path exists, just normalize it's components.
+pub fn get_canonicalized_path(path: &Path) -> PathBuf {
+    let path = expand_tilde(path);
+    let path = if path.is_relative() {
+        helix_loader::current_working_dir().join(path)
+    } else {
+        path
+    };
+
+    get_normalized_path(path.as_path())
+}
+
+pub fn get_relative_path(path: &Path) -> PathBuf {
+    let path = PathBuf::from(path);
+    let path = if path.is_absolute() {
+        let cwdir = get_normalized_path(&helix_loader::current_working_dir());
+        get_normalized_path(&path)
+            .strip_prefix(cwdir)
+            .map(PathBuf::from)
+            .unwrap_or(path)
+    } else {
+        path
+    };
+    fold_home_dir(&path)
+}
+
+/// Returns a truncated filepath where the basepart of the path is reduced to the first
+/// char of the folder and the whole filename appended.
+///
+/// Also strip the current working directory from the beginning of the path.
+/// Note that this function does not check if the truncated path is unambiguous.
+///
+/// ```   
+///    use helix_core::path::get_truncated_path;
+///    use std::path::Path;
+///
+///    assert_eq!(
+///         get_truncated_path("/home/cnorris/documents/jokes.txt").as_path(),
+///         Path::new("/h/c/d/jokes.txt")
+///     );
+///     assert_eq!(
+///         get_truncated_path("jokes.txt").as_path(),
+///         Path::new("jokes.txt")
+///     );
+///     assert_eq!(
+///         get_truncated_path("/jokes.txt").as_path(),
+///         Path::new("/jokes.txt")
+///     );
+///     assert_eq!(
+///         get_truncated_path("/h/c/d/jokes.txt").as_path(),
+///         Path::new("/h/c/d/jokes.txt")
+///     );
+///     assert_eq!(get_truncated_path("").as_path(), Path::new(""));
+/// ```
+///
+pub fn get_truncated_path<P: AsRef<Path>>(path: P) -> PathBuf {
+    let cwd = helix_loader::current_working_dir();
+    let path = path
+        .as_ref()
+        .strip_prefix(cwd)
+        .unwrap_or_else(|_| path.as_ref());
+    let file = path.file_name().unwrap_or_default();
+    let base = path.parent().unwrap_or_else(|| Path::new(""));
+    let mut ret = PathBuf::new();
+    for d in base {
+        ret.push(
+            d.to_string_lossy()
+                .chars()
+                .next()
+                .unwrap_or_default()
+                .to_string(),
+        );
+    }
+    ret.push(file);
+    ret
+}

helix-core/src/position.rs

@@ -1,6 +1,12 @@
+use std::{borrow::Cow, cmp::Ordering};
+
 use crate::{
-    graphemes::{nth_next_grapheme_boundary, RopeGraphemes},
-    Rope, RopeSlice,
+    chars::char_is_line_ending,
+    doc_formatter::{DocumentFormatter, TextFormat},
+    graphemes::{ensure_grapheme_boundary_prev, grapheme_width, RopeGraphemes},
+    line_ending::line_end_char_index,
+    text_annotations::TextAnnotations,
+    RopeSlice,
 };
 
 /// Represents a single point in a text buffer. Zero indexed.
@@ -23,8 +29,9 @@ impl Position {
     pub fn traverse(self, text: &crate::Tendril) -> Self {
         let Self { mut row, mut col } = self;
         // TODO: there should be a better way here
-        for ch in text.chars() {
-            if ch == '\n' {
+        let mut chars = text.chars().peekable();
+        while let Some(ch) = chars.next() {
+            if char_is_line_ending(ch) && !(ch == '\r' && chars.peek() == Some(&'\n')) {
                 row += 1;
                 col = 0;
             } else {
@@ -50,24 +57,351 @@ impl From<Position> for tree_sitter::Point {
     }
 }
 /// Convert a character index to (line, column) coordinates.
+///
+/// column in `char` count which can be used for row:column display in
+/// status line. See [`visual_coords_at_pos`] for a visual one.
 pub fn coords_at_pos(text: RopeSlice, pos: usize) -> Position {
     let line = text.char_to_line(pos);
+
     let line_start = text.line_to_char(line);
+    let pos = ensure_grapheme_boundary_prev(text, pos);
     let col = RopeGraphemes::new(text.slice(line_start..pos)).count();
+
     Position::new(line, col)
 }
 
+/// Convert a character index to (line, column) coordinates visually.
+///
+/// Takes \t, double-width characters (CJK) into account as well as text
+/// not in the document in the future.
+/// See [`coords_at_pos`] for an "objective" one.
+///
+/// This function should be used very rarely. Usually `visual_offset_from_anchor`
+/// or `visual_offset_from_block` is preferable. However when you want to compute the
+/// actual visual row/column in the text (not what is actually shown on screen)
+/// then you should use this function. For example aligning text should ignore virtual
+/// text and softwrap.
+#[deprecated = "Doesn't account for softwrap or decorations, use visual_offset_from_anchor instead"]
+pub fn visual_coords_at_pos(text: RopeSlice, pos: usize, tab_width: usize) -> Position {
+    let line = text.char_to_line(pos);
+
+    let line_start = text.line_to_char(line);
+    let pos = ensure_grapheme_boundary_prev(text, pos);
+
+    let mut col = 0;
+
+    for grapheme in RopeGraphemes::new(text.slice(line_start..pos)) {
+        if grapheme == "\t" {
+            col += tab_width - (col % tab_width);
+        } else {
+            let grapheme = Cow::from(grapheme);
+            col += grapheme_width(&grapheme);
+        }
+    }
+
+    Position::new(line, col)
+}
+
+/// Returns the visual offset from the start of the first visual line
+/// in the block that contains anchor.
+/// Text is always wrapped at blocks, they usually correspond to
+/// actual line breaks but for very long lines
+/// softwrapping positions are estimated with an O(1) algorithm
+/// to ensure consistent performance for large lines (currently unimplemented)
+///
+/// Usually you want to use `visual_offset_from_anchor` instead but this function
+/// can be useful (and faster) if
+/// * You already know the visual position of the block
+/// * You only care about the horizontal offset (column) and not the vertical offset (row)
+pub fn visual_offset_from_block(
+    text: RopeSlice,
+    anchor: usize,
+    pos: usize,
+    text_fmt: &TextFormat,
+    annotations: &TextAnnotations,
+) -> (Position, usize) {
+    let mut last_pos = Position::default();
+    let (formatter, block_start) =
+        DocumentFormatter::new_at_prev_checkpoint(text, text_fmt, annotations, anchor);
+    let mut char_pos = block_start;
+
+    for (grapheme, vpos) in formatter {
+        last_pos = vpos;
+        char_pos += grapheme.doc_chars();
+
+        if char_pos > pos {
+            return (last_pos, block_start);
+        }
+    }
+
+    (last_pos, block_start)
+}
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum VisualOffsetError {
+    PosBeforeAnchorRow,
+    PosAfterMaxRow,
+}
+
+/// Returns the visual offset from the start of the visual line
+/// that contains anchor.
+pub fn visual_offset_from_anchor(
+    text: RopeSlice,
+    anchor: usize,
+    pos: usize,
+    text_fmt: &TextFormat,
+    annotations: &TextAnnotations,
+    max_rows: usize,
+) -> Result<(Position, usize), VisualOffsetError> {
+    let (formatter, block_start) =
+        DocumentFormatter::new_at_prev_checkpoint(text, text_fmt, annotations, anchor);
+    let mut char_pos = block_start;
+    let mut anchor_line = None;
+    let mut found_pos = None;
+    let mut last_pos = Position::default();
+
+    if pos < block_start {
+        return Err(VisualOffsetError::PosBeforeAnchorRow);
+    }
+
+    for (grapheme, vpos) in formatter {
+        last_pos = vpos;
+        char_pos += grapheme.doc_chars();
+
+        if char_pos > pos {
+            if let Some(anchor_line) = anchor_line {
+                last_pos.row -= anchor_line;
+                return Ok((last_pos, block_start));
+            } else {
+                found_pos = Some(last_pos);
+            }
+        }
+        if char_pos > anchor && anchor_line.is_none() {
+            if let Some(mut found_pos) = found_pos {
+                return if found_pos.row == last_pos.row {
+                    found_pos.row = 0;
+                    Ok((found_pos, block_start))
+                } else {
+                    Err(VisualOffsetError::PosBeforeAnchorRow)
+                };
+            } else {
+                anchor_line = Some(last_pos.row);
+            }
+        }
+
+        if let Some(anchor_line) = anchor_line {
+            if vpos.row >= anchor_line + max_rows {
+                return Err(VisualOffsetError::PosAfterMaxRow);
+            }
+        }
+    }
+
+    let anchor_line = anchor_line.unwrap_or(last_pos.row);
+    last_pos.row -= anchor_line;
+
+    Ok((last_pos, block_start))
+}
+
 /// Convert (line, column) coordinates to a character index.
-pub fn pos_at_coords(text: RopeSlice, coords: Position) -> usize {
-    let Position { row, col } = coords;
+///
+/// If the `line` coordinate is beyond the end of the file, the EOF
+/// position will be returned.
+///
+/// If the `column` coordinate is past the end of the given line, the
+/// line-end position will be returned.  What constitutes the "line-end
+/// position" depends on the parameter `limit_before_line_ending`.  If it's
+/// `true`, the line-end position will be just *before* the line ending
+/// character.  If `false` it will be just *after* the line ending
+/// character--on the border between the current line and the next.
+///
+/// Usually you only want `limit_before_line_ending` to be `true` if you're working
+/// with left-side block-cursor positions, as this prevents the the block cursor
+/// from jumping to the next line.  Otherwise you typically want it to be `false`,
+/// such as when dealing with raw anchor/head positions.
+pub fn pos_at_coords(text: RopeSlice, coords: Position, limit_before_line_ending: bool) -> usize {
+    let Position { mut row, col } = coords;
+    if limit_before_line_ending {
+        row = row.min(text.len_lines() - 1);
+    };
     let line_start = text.line_to_char(row);
-    // line_start + col
-    nth_next_grapheme_boundary(text, line_start, col)
+    let line_end = if limit_before_line_ending {
+        line_end_char_index(&text, row)
+    } else {
+        text.line_to_char((row + 1).min(text.len_lines()))
+    };
+
+    let mut col_char_offset = 0;
+    for (i, g) in RopeGraphemes::new(text.slice(line_start..line_end)).enumerate() {
+        if i == col {
+            break;
+        }
+        col_char_offset += g.chars().count();
+    }
+
+    line_start + col_char_offset
+}
+
+/// Convert visual (line, column) coordinates to a character index.
+///
+/// If the `line` coordinate is beyond the end of the file, the EOF
+/// position will be returned.
+///
+/// If the `column` coordinate is past the end of the given line, the
+/// line-end position (in this case, just before the line ending
+/// character) will be returned.
+/// This function should be used very rarely. Usually `char_idx_at_visual_offset` is preferable.
+/// However when you want to compute a char position from the visual row/column in the text
+/// (not what is actually shown on screen) then you should use this function.
+/// For example aligning text should ignore virtual text and softwrap.
+#[deprecated = "Doesn't account for softwrap or decorations, use char_idx_at_visual_offset instead"]
+pub fn pos_at_visual_coords(text: RopeSlice, coords: Position, tab_width: usize) -> usize {
+    let Position { mut row, col } = coords;
+    row = row.min(text.len_lines() - 1);
+    let line_start = text.line_to_char(row);
+    let line_end = line_end_char_index(&text, row);
+
+    let mut col_char_offset = 0;
+    let mut cols_remaining = col;
+    for grapheme in RopeGraphemes::new(text.slice(line_start..line_end)) {
+        let grapheme_width = if grapheme == "\t" {
+            tab_width - ((col - cols_remaining) % tab_width)
+        } else {
+            let grapheme = Cow::from(grapheme);
+            grapheme_width(&grapheme)
+        };
+
+        // If pos is in the middle of a wider grapheme (tab for example)
+        // return the starting offset.
+        if grapheme_width > cols_remaining {
+            break;
+        }
+
+        cols_remaining -= grapheme_width;
+        col_char_offset += grapheme.chars().count();
+    }
+
+    line_start + col_char_offset
+}
+
+/// Returns the char index on the visual line `row_offset` below the visual line of
+/// the provided char index `anchor` that is closest to the supplied visual `column`.
+///
+/// If the targeted visual line is entirely covered by virtual text the last
+/// char position before the virtual text and a virtual offset is returned instead.
+///
+/// If no (text) grapheme starts at exactly at the specified column the
+/// start of the grapheme to the left is returned. If there is no grapheme
+/// to the left (for example if the line starts with virtual text) then the positioning
+/// of the next grapheme to the right is returned.
+///
+/// If the `line` coordinate is beyond the end of the file, the EOF
+/// position will be returned.
+///
+/// If the `column` coordinate is past the end of the given line, the
+/// line-end position (in this case, just before the line ending
+/// character) will be returned.
+///
+/// # Returns
+///
+/// `(real_char_idx, virtual_lines)`
+///
+/// The nearest character idx "closest" (see above) to the specified visual offset
+/// on the visual line is returned if the visual line contains any text:
+/// If the visual line at the specified offset is a virtual line generated by a `LineAnnotation`
+/// the previous char_index is returned, together with the remaining vertical offset (`virtual_lines`)
+pub fn char_idx_at_visual_offset(
+    text: RopeSlice,
+    mut anchor: usize,
+    mut row_offset: isize,
+    column: usize,
+    text_fmt: &TextFormat,
+    annotations: &TextAnnotations,
+) -> (usize, usize) {
+    let mut pos = anchor;
+    // convert row relative to visual line containing anchor to row relative to a block containing anchor (anchor may change)
+    loop {
+        let (visual_pos_in_block, block_char_offset) =
+            visual_offset_from_block(text, anchor, pos, text_fmt, annotations);
+        row_offset += visual_pos_in_block.row as isize;
+        anchor = block_char_offset;
+        if row_offset >= 0 {
+            break;
+        }
+
+        if block_char_offset == 0 {
+            row_offset = 0;
+            break;
+        }
+        // the row_offset is negative so we need to look at the previous block
+        // set the anchor to the last char before the current block so that we can compute
+        // the distance of this block from the start of the previous block
+        pos = anchor;
+        anchor -= 1;
+    }
+
+    char_idx_at_visual_block_offset(
+        text,
+        anchor,
+        row_offset as usize,
+        column,
+        text_fmt,
+        annotations,
+    )
+}
+
+/// This function behaves the same as `char_idx_at_visual_offset`, except that
+/// the vertical offset `row` is always computed relative to the block that contains `anchor`
+/// instead of the visual line that contains `anchor`.
+/// Usually `char_idx_at_visual_offset` is more useful but this function can be
+/// used in some situations as an optimization when `visual_offset_from_block` was used
+///
+/// # Returns
+///
+/// `(real_char_idx, virtual_lines)`
+///
+/// See `char_idx_at_visual_offset` for details
+pub fn char_idx_at_visual_block_offset(
+    text: RopeSlice,
+    anchor: usize,
+    row: usize,
+    column: usize,
+    text_fmt: &TextFormat,
+    annotations: &TextAnnotations,
+) -> (usize, usize) {
+    let (formatter, mut char_idx) =
+        DocumentFormatter::new_at_prev_checkpoint(text, text_fmt, annotations, anchor);
+    let mut last_char_idx = char_idx;
+    let mut last_char_idx_on_line = None;
+    let mut last_row = 0;
+    for (grapheme, grapheme_pos) in formatter {
+        match grapheme_pos.row.cmp(&row) {
+            Ordering::Equal => {
+                if grapheme_pos.col + grapheme.width() > column {
+                    if !grapheme.is_virtual() {
+                        return (char_idx, 0);
+                    } else if let Some(char_idx) = last_char_idx_on_line {
+                        return (char_idx, 0);
+                    }
+                } else if !grapheme.is_virtual() {
+                    last_char_idx_on_line = Some(char_idx)
+                }
+            }
+            Ordering::Greater => return (last_char_idx, row - last_row),
+            _ => (),
+        }
+
+        last_char_idx = char_idx;
+        last_row = grapheme_pos.row;
+        char_idx += grapheme.doc_chars();
+    }
+
+    (char_idx, 0)
 }
 
 #[cfg(test)]
 mod test {
     use super::*;
+    use crate::Rope;
 
     #[test]
     fn test_ordering() {
@@ -79,53 +413,447 @@ mod test {
     fn test_coords_at_pos() {
         let text = Rope::from("ḧëḷḷö\nẅöṛḷḋ");
         let slice = text.slice(..);
-        // assert_eq!(coords_at_pos(slice, 0), (0, 0).into());
-        // assert_eq!(coords_at_pos(slice, 5), (0, 5).into()); // position on \n
-        // assert_eq!(coords_at_pos(slice, 6), (1, 0).into()); // position on w
-        // assert_eq!(coords_at_pos(slice, 7), (1, 1).into()); // position on o
-        // assert_eq!(coords_at_pos(slice, 10), (1, 4).into()); // position on d
+        assert_eq!(coords_at_pos(slice, 0), (0, 0).into());
+        assert_eq!(coords_at_pos(slice, 5), (0, 5).into()); // position on \n
+        assert_eq!(coords_at_pos(slice, 6), (1, 0).into()); // position on w
+        assert_eq!(coords_at_pos(slice, 7), (1, 1).into()); // position on o
+        assert_eq!(coords_at_pos(slice, 10), (1, 4).into()); // position on d
 
-        // test with grapheme clusters
+        // Test with wide characters.
+        let text = Rope::from("今日はいい\n");
+        let slice = text.slice(..);
+        assert_eq!(coords_at_pos(slice, 0), (0, 0).into());
+        assert_eq!(coords_at_pos(slice, 1), (0, 1).into());
+        assert_eq!(coords_at_pos(slice, 2), (0, 2).into());
+        assert_eq!(coords_at_pos(slice, 3), (0, 3).into());
+        assert_eq!(coords_at_pos(slice, 4), (0, 4).into());
+        assert_eq!(coords_at_pos(slice, 5), (0, 5).into());
+        assert_eq!(coords_at_pos(slice, 6), (1, 0).into());
+
+        // Test with grapheme clusters.
         let text = Rope::from("a̐éö̲\r\n");
         let slice = text.slice(..);
         assert_eq!(coords_at_pos(slice, 0), (0, 0).into());
         assert_eq!(coords_at_pos(slice, 2), (0, 1).into());
         assert_eq!(coords_at_pos(slice, 4), (0, 2).into());
         assert_eq!(coords_at_pos(slice, 7), (0, 3).into());
+        assert_eq!(coords_at_pos(slice, 9), (1, 0).into());
 
-        let text = Rope::from("किमपि");
+        // Test with wide-character grapheme clusters.
+        let text = Rope::from("किमपि\n");
         let slice = text.slice(..);
         assert_eq!(coords_at_pos(slice, 0), (0, 0).into());
         assert_eq!(coords_at_pos(slice, 2), (0, 1).into());
         assert_eq!(coords_at_pos(slice, 3), (0, 2).into());
         assert_eq!(coords_at_pos(slice, 5), (0, 3).into());
+        assert_eq!(coords_at_pos(slice, 6), (1, 0).into());
+
+        // Test with tabs.
+        let text = Rope::from("\tHello\n");
+        let slice = text.slice(..);
+        assert_eq!(coords_at_pos(slice, 0), (0, 0).into());
+        assert_eq!(coords_at_pos(slice, 1), (0, 1).into());
+        assert_eq!(coords_at_pos(slice, 2), (0, 2).into());
     }
 
+    #[test]
+    #[allow(deprecated)]
+    fn test_visual_coords_at_pos() {
+        let text = Rope::from("ḧëḷḷö\nẅöṛḷḋ");
+        let slice = text.slice(..);
+        assert_eq!(visual_coords_at_pos(slice, 0, 8), (0, 0).into());
+        assert_eq!(visual_coords_at_pos(slice, 5, 8), (0, 5).into()); // position on \n
+        assert_eq!(visual_coords_at_pos(slice, 6, 8), (1, 0).into()); // position on w
+        assert_eq!(visual_coords_at_pos(slice, 7, 8), (1, 1).into()); // position on o
+        assert_eq!(visual_coords_at_pos(slice, 10, 8), (1, 4).into()); // position on d
+
+        // Test with wide characters.
+        let text = Rope::from("今日はいい\n");
+        let slice = text.slice(..);
+        assert_eq!(visual_coords_at_pos(slice, 0, 8), (0, 0).into());
+        assert_eq!(visual_coords_at_pos(slice, 1, 8), (0, 2).into());
+        assert_eq!(visual_coords_at_pos(slice, 2, 8), (0, 4).into());
+        assert_eq!(visual_coords_at_pos(slice, 3, 8), (0, 6).into());
+        assert_eq!(visual_coords_at_pos(slice, 4, 8), (0, 8).into());
+        assert_eq!(visual_coords_at_pos(slice, 5, 8), (0, 10).into());
+        assert_eq!(visual_coords_at_pos(slice, 6, 8), (1, 0).into());
+
+        // Test with grapheme clusters.
+        let text = Rope::from("a̐éö̲\r\n");
+        let slice = text.slice(..);
+        assert_eq!(visual_coords_at_pos(slice, 0, 8), (0, 0).into());
+        assert_eq!(visual_coords_at_pos(slice, 2, 8), (0, 1).into());
+        assert_eq!(visual_coords_at_pos(slice, 4, 8), (0, 2).into());
+        assert_eq!(visual_coords_at_pos(slice, 7, 8), (0, 3).into());
+        assert_eq!(visual_coords_at_pos(slice, 9, 8), (1, 0).into());
+
+        // Test with wide-character grapheme clusters.
+        // TODO: account for cluster.
+        let text = Rope::from("किमपि\n");
+        let slice = text.slice(..);
+        assert_eq!(visual_coords_at_pos(slice, 0, 8), (0, 0).into());
+        assert_eq!(visual_coords_at_pos(slice, 2, 8), (0, 2).into());
+        assert_eq!(visual_coords_at_pos(slice, 3, 8), (0, 3).into());
+        assert_eq!(visual_coords_at_pos(slice, 5, 8), (0, 5).into());
+        assert_eq!(visual_coords_at_pos(slice, 6, 8), (1, 0).into());
+
+        // Test with tabs.
+        let text = Rope::from("\tHello\n");
+        let slice = text.slice(..);
+        assert_eq!(visual_coords_at_pos(slice, 0, 8), (0, 0).into());
+        assert_eq!(visual_coords_at_pos(slice, 1, 8), (0, 8).into());
+        assert_eq!(visual_coords_at_pos(slice, 2, 8), (0, 9).into());
+    }
+
+    #[test]
+    fn test_visual_off_from_block() {
+        let text = Rope::from("ḧëḷḷö\nẅöṛḷḋ");
+        let slice = text.slice(..);
+        let annot = TextAnnotations::default();
+        let text_fmt = TextFormat::default();
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 0, &text_fmt, &annot).0,
+            (0, 0).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 5, &text_fmt, &annot).0,
+            (0, 5).into()
+        ); // position on \n
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 6, &text_fmt, &annot).0,
+            (1, 0).into()
+        ); // position on w
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 7, &text_fmt, &annot).0,
+            (1, 1).into()
+        ); // position on o
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 10, &text_fmt, &annot).0,
+            (1, 4).into()
+        ); // position on d
+
+        // Test with wide characters.
+        let text = Rope::from("今日はいい\n");
+        let slice = text.slice(..);
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 0, &text_fmt, &annot).0,
+            (0, 0).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 1, &text_fmt, &annot).0,
+            (0, 2).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 2, &text_fmt, &annot).0,
+            (0, 4).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 3, &text_fmt, &annot).0,
+            (0, 6).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 4, &text_fmt, &annot).0,
+            (0, 8).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 5, &text_fmt, &annot).0,
+            (0, 10).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 6, &text_fmt, &annot).0,
+            (1, 0).into()
+        );
+
+        // Test with grapheme clusters.
+        let text = Rope::from("a̐éö̲\r\n");
+        let slice = text.slice(..);
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 0, &text_fmt, &annot).0,
+            (0, 0).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 2, &text_fmt, &annot).0,
+            (0, 1).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 4, &text_fmt, &annot).0,
+            (0, 2).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 7, &text_fmt, &annot).0,
+            (0, 3).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 9, &text_fmt, &annot).0,
+            (1, 0).into()
+        );
+
+        // Test with wide-character grapheme clusters.
+        // TODO: account for cluster.
+        let text = Rope::from("किमपि\n");
+        let slice = text.slice(..);
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 0, &text_fmt, &annot).0,
+            (0, 0).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 2, &text_fmt, &annot).0,
+            (0, 2).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 3, &text_fmt, &annot).0,
+            (0, 3).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 5, &text_fmt, &annot).0,
+            (0, 5).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 6, &text_fmt, &annot).0,
+            (1, 0).into()
+        );
+
+        // Test with tabs.
+        let text = Rope::from("\tHello\n");
+        let slice = text.slice(..);
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 0, &text_fmt, &annot).0,
+            (0, 0).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 1, &text_fmt, &annot).0,
+            (0, 4).into()
+        );
+        assert_eq!(
+            visual_offset_from_block(slice, 0, 2, &text_fmt, &annot).0,
+            (0, 5).into()
+        );
+    }
     #[test]
     fn test_pos_at_coords() {
         let text = Rope::from("ḧëḷḷö\nẅöṛḷḋ");
         let slice = text.slice(..);
-        assert_eq!(pos_at_coords(slice, (0, 0).into()), 0);
-        assert_eq!(pos_at_coords(slice, (0, 5).into()), 5); // position on \n
-        assert_eq!(pos_at_coords(slice, (1, 0).into()), 6); // position on w
-        assert_eq!(pos_at_coords(slice, (1, 1).into()), 7); // position on o
-        assert_eq!(pos_at_coords(slice, (1, 4).into()), 10); // position on d
+        assert_eq!(pos_at_coords(slice, (0, 0).into(), false), 0);
+        assert_eq!(pos_at_coords(slice, (0, 5).into(), false), 5); // position on \n
+        assert_eq!(pos_at_coords(slice, (0, 6).into(), false), 6); // position after \n
+        assert_eq!(pos_at_coords(slice, (0, 6).into(), true), 5); // position after \n
+        assert_eq!(pos_at_coords(slice, (1, 0).into(), false), 6); // position on w
+        assert_eq!(pos_at_coords(slice, (1, 1).into(), false), 7); // position on o
+        assert_eq!(pos_at_coords(slice, (1, 4).into(), false), 10); // position on d
 
-        // test with grapheme clusters
+        // Test with wide characters.
+        // TODO: account for character width.
+        let text = Rope::from("今日はいい\n");
+        let slice = text.slice(..);
+        assert_eq!(pos_at_coords(slice, (0, 0).into(), false), 0);
+        assert_eq!(pos_at_coords(slice, (0, 1).into(), false), 1);
+        assert_eq!(pos_at_coords(slice, (0, 2).into(), false), 2);
+        assert_eq!(pos_at_coords(slice, (0, 3).into(), false), 3);
+        assert_eq!(pos_at_coords(slice, (0, 4).into(), false), 4);
+        assert_eq!(pos_at_coords(slice, (0, 5).into(), false), 5);
+        assert_eq!(pos_at_coords(slice, (0, 6).into(), false), 6);
+        assert_eq!(pos_at_coords(slice, (0, 6).into(), true), 5);
+        assert_eq!(pos_at_coords(slice, (1, 0).into(), false), 6);
+
+        // Test with grapheme clusters.
         let text = Rope::from("a̐éö̲\r\n");
         let slice = text.slice(..);
-        assert_eq!(pos_at_coords(slice, (0, 0).into()), 0);
-        assert_eq!(pos_at_coords(slice, (0, 1).into()), 2);
-        assert_eq!(pos_at_coords(slice, (0, 2).into()), 4);
-        assert_eq!(pos_at_coords(slice, (0, 3).into()), 7); // \r\n is one char here
-        assert_eq!(pos_at_coords(slice, (0, 4).into()), 9);
+        assert_eq!(pos_at_coords(slice, (0, 0).into(), false), 0);
+        assert_eq!(pos_at_coords(slice, (0, 1).into(), false), 2);
+        assert_eq!(pos_at_coords(slice, (0, 2).into(), false), 4);
+        assert_eq!(pos_at_coords(slice, (0, 3).into(), false), 7); // \r\n is one char here
+        assert_eq!(pos_at_coords(slice, (0, 4).into(), false), 9);
+        assert_eq!(pos_at_coords(slice, (0, 4).into(), true), 7);
+        assert_eq!(pos_at_coords(slice, (1, 0).into(), false), 9);
+
+        // Test with wide-character grapheme clusters.
+        // TODO: account for character width.
         let text = Rope::from("किमपि");
         // 2 - 1 - 2 codepoints
         // TODO: delete handling as per https://news.ycombinator.com/item?id=20058454
         let slice = text.slice(..);
-        assert_eq!(pos_at_coords(slice, (0, 0).into()), 0);
-        assert_eq!(pos_at_coords(slice, (0, 1).into()), 2);
-        assert_eq!(pos_at_coords(slice, (0, 2).into()), 3);
-        assert_eq!(pos_at_coords(slice, (0, 3).into()), 5); // eol
+        assert_eq!(pos_at_coords(slice, (0, 0).into(), false), 0);
+        assert_eq!(pos_at_coords(slice, (0, 1).into(), false), 2);
+        assert_eq!(pos_at_coords(slice, (0, 2).into(), false), 3);
+        assert_eq!(pos_at_coords(slice, (0, 3).into(), false), 5);
+        assert_eq!(pos_at_coords(slice, (0, 3).into(), true), 5);
+
+        // Test with tabs.
+        // Todo: account for tab stops.
+        let text = Rope::from("\tHello\n");
+        let slice = text.slice(..);
+        assert_eq!(pos_at_coords(slice, (0, 0).into(), false), 0);
+        assert_eq!(pos_at_coords(slice, (0, 1).into(), false), 1);
+        assert_eq!(pos_at_coords(slice, (0, 2).into(), false), 2);
+
+        // Test out of bounds.
+        let text = Rope::new();
+        let slice = text.slice(..);
+        assert_eq!(pos_at_coords(slice, (10, 0).into(), true), 0);
+        assert_eq!(pos_at_coords(slice, (0, 10).into(), true), 0);
+        assert_eq!(pos_at_coords(slice, (10, 10).into(), true), 0);
+    }
+
+    #[test]
+    #[allow(deprecated)]
+    fn test_pos_at_visual_coords() {
+        let text = Rope::from("ḧëḷḷö\nẅöṛḷḋ");
+        let slice = text.slice(..);
+        assert_eq!(pos_at_visual_coords(slice, (0, 0).into(), 4), 0);
+        assert_eq!(pos_at_visual_coords(slice, (0, 5).into(), 4), 5); // position on \n
+        assert_eq!(pos_at_visual_coords(slice, (0, 6).into(), 4), 5); // position after \n
+        assert_eq!(pos_at_visual_coords(slice, (1, 0).into(), 4), 6); // position on w
+        assert_eq!(pos_at_visual_coords(slice, (1, 1).into(), 4), 7); // position on o
+        assert_eq!(pos_at_visual_coords(slice, (1, 4).into(), 4), 10); // position on d
+
+        // Test with wide characters.
+        let text = Rope::from("今日はいい\n");
+        let slice = text.slice(..);
+        assert_eq!(pos_at_visual_coords(slice, (0, 0).into(), 4), 0);
+        assert_eq!(pos_at_visual_coords(slice, (0, 1).into(), 4), 0);
+        assert_eq!(pos_at_visual_coords(slice, (0, 2).into(), 4), 1);
+        assert_eq!(pos_at_visual_coords(slice, (0, 3).into(), 4), 1);
+        assert_eq!(pos_at_visual_coords(slice, (0, 4).into(), 4), 2);
+        assert_eq!(pos_at_visual_coords(slice, (0, 5).into(), 4), 2);
+        assert_eq!(pos_at_visual_coords(slice, (0, 6).into(), 4), 3);
+        assert_eq!(pos_at_visual_coords(slice, (0, 7).into(), 4), 3);
+        assert_eq!(pos_at_visual_coords(slice, (0, 8).into(), 4), 4);
+        assert_eq!(pos_at_visual_coords(slice, (0, 9).into(), 4), 4);
+        // assert_eq!(pos_at_visual_coords(slice, (0, 10).into(), 4, false), 5);
+        // assert_eq!(pos_at_visual_coords(slice, (0, 10).into(), 4, true), 5);
+        assert_eq!(pos_at_visual_coords(slice, (1, 0).into(), 4), 6);
+
+        // Test with grapheme clusters.
+        let text = Rope::from("a̐éö̲\r\n");
+        let slice = text.slice(..);
+        assert_eq!(pos_at_visual_coords(slice, (0, 0).into(), 4), 0);
+        assert_eq!(pos_at_visual_coords(slice, (0, 1).into(), 4), 2);
+        assert_eq!(pos_at_visual_coords(slice, (0, 2).into(), 4), 4);
+        assert_eq!(pos_at_visual_coords(slice, (0, 3).into(), 4), 7); // \r\n is one char here
+        assert_eq!(pos_at_visual_coords(slice, (0, 4).into(), 4), 7);
+        assert_eq!(pos_at_visual_coords(slice, (1, 0).into(), 4), 9);
+
+        // Test with wide-character grapheme clusters.
+        let text = Rope::from("किमपि");
+        // 2 - 1 - 2 codepoints
+        // TODO: delete handling as per https://news.ycombinator.com/item?id=20058454
+        let slice = text.slice(..);
+        assert_eq!(pos_at_visual_coords(slice, (0, 0).into(), 4), 0);
+        assert_eq!(pos_at_visual_coords(slice, (0, 1).into(), 4), 0);
+        assert_eq!(pos_at_visual_coords(slice, (0, 2).into(), 4), 2);
+        assert_eq!(pos_at_visual_coords(slice, (0, 3).into(), 4), 3);
+
+        // Test with tabs.
+        let text = Rope::from("\tHello\n");
+        let slice = text.slice(..);
+        assert_eq!(pos_at_visual_coords(slice, (0, 0).into(), 4), 0);
+        assert_eq!(pos_at_visual_coords(slice, (0, 1).into(), 4), 0);
+        assert_eq!(pos_at_visual_coords(slice, (0, 2).into(), 4), 0);
+        assert_eq!(pos_at_visual_coords(slice, (0, 3).into(), 4), 0);
+        assert_eq!(pos_at_visual_coords(slice, (0, 4).into(), 4), 1);
+        assert_eq!(pos_at_visual_coords(slice, (0, 5).into(), 4), 2);
+
+        // Test out of bounds.
+        let text = Rope::new();
+        let slice = text.slice(..);
+        assert_eq!(pos_at_visual_coords(slice, (10, 0).into(), 4), 0);
+        assert_eq!(pos_at_visual_coords(slice, (0, 10).into(), 4), 0);
+        assert_eq!(pos_at_visual_coords(slice, (10, 10).into(), 4), 0);
+    }
+
+    #[test]
+    fn test_char_idx_at_visual_row_offset() {
+        let text = Rope::from("ḧëḷḷö\nẅöṛḷḋ\nfoo");
+        let slice = text.slice(..);
+        let mut text_fmt = TextFormat::default();
+        for i in 0isize..3isize {
+            for j in -2isize..=2isize {
+                if !(0..3).contains(&(i + j)) {
+                    continue;
+                }
+                println!("{i} {j}");
+                assert_eq!(
+                    char_idx_at_visual_offset(
+                        slice,
+                        slice.line_to_char(i as usize),
+                        j,
+                        3,
+                        &text_fmt,
+                        &TextAnnotations::default(),
+                    )
+                    .0,
+                    slice.line_to_char((i + j) as usize) + 3
+                );
+            }
+        }
+
+        text_fmt.soft_wrap = true;
+        let mut softwrapped_text = "foo ".repeat(10);
+        softwrapped_text.push('\n');
+        let last_char = softwrapped_text.len() - 1;
+
+        let text = Rope::from(softwrapped_text.repeat(3));
+        let slice = text.slice(..);
+        assert_eq!(
+            char_idx_at_visual_offset(
+                slice,
+                last_char,
+                0,
+                0,
+                &text_fmt,
+                &TextAnnotations::default(),
+            )
+            .0,
+            32
+        );
+        assert_eq!(
+            char_idx_at_visual_offset(
+                slice,
+                last_char,
+                -1,
+                0,
+                &text_fmt,
+                &TextAnnotations::default(),
+            )
+            .0,
+            16
+        );
+        assert_eq!(
+            char_idx_at_visual_offset(
+                slice,
+                last_char,
+                -2,
+                0,
+                &text_fmt,
+                &TextAnnotations::default(),
+            )
+            .0,
+            0
+        );
+        assert_eq!(
+            char_idx_at_visual_offset(
+                slice,
+                softwrapped_text.len() + last_char,
+                -2,
+                0,
+                &text_fmt,
+                &TextAnnotations::default(),
+            )
+            .0,
+            softwrapped_text.len()
+        );
+
+        assert_eq!(
+            char_idx_at_visual_offset(
+                slice,
+                softwrapped_text.len() + last_char,
+                -5,
+                0,
+                &text_fmt,
+                &TextAnnotations::default(),
+            )
+            .0,
+            0
+        );
     }
 }

helix-core/src/register.rs

@@ -1,21 +0,0 @@
-use crate::Tendril;
-use once_cell::sync::Lazy;
-use std::{collections::HashMap, sync::RwLock};
-
-// TODO: could be an instance on Editor
-static REGISTRY: Lazy<RwLock<HashMap<char, Vec<String>>>> =
-    Lazy::new(|| RwLock::new(HashMap::new()));
-
-pub fn get(register: char) -> Option<Vec<String>> {
-    let registry = REGISTRY.read().unwrap();
-
-    // TODO: no cloning
-    registry.get(&register).cloned()
-}
-
-// restoring: bool
-pub fn set(register: char, values: Vec<String>) {
-    let mut registry = REGISTRY.write().unwrap();
-
-    registry.insert(register, values);
-}

helix-core/src/rope_reader.rs

@@ -0,0 +1,37 @@
+use std::io;
+
+use ropey::iter::Chunks;
+use ropey::RopeSlice;
+
+pub struct RopeReader<'a> {
+    current_chunk: &'a [u8],
+    chunks: Chunks<'a>,
+}
+
+impl<'a> RopeReader<'a> {
+    pub fn new(rope: RopeSlice<'a>) -> RopeReader<'a> {
+        RopeReader {
+            current_chunk: &[],
+            chunks: rope.chunks(),
+        }
+    }
+}
+
+impl io::Read for RopeReader<'_> {
+    fn read(&mut self, mut buf: &mut [u8]) -> io::Result<usize> {
+        let buf_len = buf.len();
+        loop {
+            let read_bytes = self.current_chunk.read(buf)?;
+            buf = &mut buf[read_bytes..];
+            if buf.is_empty() {
+                return Ok(buf_len);
+            }
+
+            if let Some(next_chunk) = self.chunks.next() {
+                self.current_chunk = next_chunk.as_bytes();
+            } else {
+                return Ok(buf_len - buf.len());
+            }
+        }
+    }
+}

helix-core/src/search.rs

@@ -1,14 +1,33 @@
 use crate::RopeSlice;
 
-pub fn find_nth_next(
+// TODO: switch to std::str::Pattern when it is stable.
+pub trait CharMatcher {
+    fn char_match(&self, ch: char) -> bool;
+}
+
+impl CharMatcher for char {
+    fn char_match(&self, ch: char) -> bool {
+        *self == ch
+    }
+}
+
+impl<F: Fn(&char) -> bool> CharMatcher for F {
+    fn char_match(&self, ch: char) -> bool {
+        (*self)(&ch)
+    }
+}
+
+pub fn find_nth_next<M: CharMatcher>(
     text: RopeSlice,
-    ch: char,
+    char_matcher: M,
     mut pos: usize,
     n: usize,
-    inclusive: bool,
 ) -> Option<usize> {
-    // start searching right after pos
-    let mut chars = text.chars_at(pos + 1);
+    if pos >= text.len_chars() || n == 0 {
+        return None;
+    }
+
+    let mut chars = text.chars_at(pos);
 
     for _ in 0..n {
         loop {
@@ -16,34 +35,27 @@ pub fn find_nth_next(
 
             pos += 1;
 
-            if c == ch {
+            if char_matcher.char_match(c) {
                 break;
             }
         }
     }
 
-    if !inclusive {
-        pos -= 1;
-    }
-
-    Some(pos)
+    Some(pos - 1)
 }
 
-pub fn find_nth_prev(
-    text: RopeSlice,
-    ch: char,
-    mut pos: usize,
-    n: usize,
-    inclusive: bool,
-) -> Option<usize> {
-    // start searching right before pos
-    let mut chars = text.chars_at(pos.saturating_sub(1));
+pub fn find_nth_prev(text: RopeSlice, ch: char, mut pos: usize, n: usize) -> Option<usize> {
+    if pos == 0 || n == 0 {
+        return None;
+    }
+
+    let mut chars = text.chars_at(pos);
 
     for _ in 0..n {
         loop {
             let c = chars.prev()?;
 
-            pos = pos.saturating_sub(1);
+            pos -= 1;
 
             if c == ch {
                 break;
@@ -51,9 +63,5 @@ pub fn find_nth_prev(
         }
     }
 
-    if !inclusive {
-        pos -= 1;
-    }
-
     Some(pos)
 }

helix-core/src/shellwords.rs

@@ -0,0 +1,350 @@
+use std::borrow::Cow;
+
+/// Auto escape for shellwords usage.
+pub fn escape(input: Cow<str>) -> Cow<str> {
+    if !input.chars().any(|x| x.is_ascii_whitespace()) {
+        input
+    } else if cfg!(unix) {
+        Cow::Owned(input.chars().fold(String::new(), |mut buf, c| {
+            if c.is_ascii_whitespace() {
+                buf.push('\\');
+            }
+            buf.push(c);
+            buf
+        }))
+    } else {
+        Cow::Owned(format!("\"{}\"", input))
+    }
+}
+
+enum State {
+    OnWhitespace,
+    Unquoted,
+    UnquotedEscaped,
+    Quoted,
+    QuoteEscaped,
+    Dquoted,
+    DquoteEscaped,
+}
+
+pub struct Shellwords<'a> {
+    state: State,
+    /// Shellwords where whitespace and escapes has been resolved.
+    words: Vec<Cow<'a, str>>,
+    /// The parts of the input that are divided into shellwords. This can be
+    /// used to retrieve the original text for a given word by looking up the
+    /// same index in the Vec as the word in `words`.
+    parts: Vec<&'a str>,
+}
+
+impl<'a> From<&'a str> for Shellwords<'a> {
+    fn from(input: &'a str) -> Self {
+        use State::*;
+
+        let mut state = Unquoted;
+        let mut words = Vec::new();
+        let mut parts = Vec::new();
+        let mut escaped = String::with_capacity(input.len());
+
+        let mut part_start = 0;
+        let mut unescaped_start = 0;
+        let mut end = 0;
+
+        for (i, c) in input.char_indices() {
+            state = match state {
+                OnWhitespace => match c {
+                    '"' => {
+                        end = i;
+                        Dquoted
+                    }
+                    '\'' => {
+                        end = i;
+                        Quoted
+                    }
+                    '\\' => {
+                        if cfg!(unix) {
+                            escaped.push_str(&input[unescaped_start..i]);
+                            unescaped_start = i + 1;
+                            UnquotedEscaped
+                        } else {
+                            OnWhitespace
+                        }
+                    }
+                    c if c.is_ascii_whitespace() => {
+                        end = i;
+                        OnWhitespace
+                    }
+                    _ => Unquoted,
+                },
+                Unquoted => match c {
+                    '\\' => {
+                        if cfg!(unix) {
+                            escaped.push_str(&input[unescaped_start..i]);
+                            unescaped_start = i + 1;
+                            UnquotedEscaped
+                        } else {
+                            Unquoted
+                        }
+                    }
+                    c if c.is_ascii_whitespace() => {
+                        end = i;
+                        OnWhitespace
+                    }
+                    _ => Unquoted,
+                },
+                UnquotedEscaped => Unquoted,
+                Quoted => match c {
+                    '\\' => {
+                        if cfg!(unix) {
+                            escaped.push_str(&input[unescaped_start..i]);
+                            unescaped_start = i + 1;
+                            QuoteEscaped
+                        } else {
+                            Quoted
+                        }
+                    }
+                    '\'' => {
+                        end = i;
+                        OnWhitespace
+                    }
+                    _ => Quoted,
+                },
+                QuoteEscaped => Quoted,
+                Dquoted => match c {
+                    '\\' => {
+                        if cfg!(unix) {
+                            escaped.push_str(&input[unescaped_start..i]);
+                            unescaped_start = i + 1;
+                            DquoteEscaped
+                        } else {
+                            Dquoted
+                        }
+                    }
+                    '"' => {
+                        end = i;
+                        OnWhitespace
+                    }
+                    _ => Dquoted,
+                },
+                DquoteEscaped => Dquoted,
+            };
+
+            let c_len = c.len_utf8();
+            if i == input.len() - c_len && end == 0 {
+                end = i + c_len;
+            }
+
+            if end > 0 {
+                let esc_trim = escaped.trim();
+                let inp = &input[unescaped_start..end];
+
+                if !(esc_trim.is_empty() && inp.trim().is_empty()) {
+                    if esc_trim.is_empty() {
+                        words.push(inp.into());
+                        parts.push(inp);
+                    } else {
+                        words.push([escaped, inp.into()].concat().into());
+                        parts.push(&input[part_start..end]);
+                        escaped = "".to_string();
+                    }
+                }
+                unescaped_start = i + 1;
+                part_start = i + 1;
+                end = 0;
+            }
+        }
+
+        debug_assert!(words.len() == parts.len());
+
+        Self {
+            state,
+            words,
+            parts,
+        }
+    }
+}
+
+impl<'a> Shellwords<'a> {
+    /// Checks that the input ends with a whitespace character which is not escaped.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use helix_core::shellwords::Shellwords;
+    /// assert_eq!(Shellwords::from(" ").ends_with_whitespace(), true);
+    /// assert_eq!(Shellwords::from(":open ").ends_with_whitespace(), true);
+    /// assert_eq!(Shellwords::from(":open foo.txt ").ends_with_whitespace(), true);
+    /// assert_eq!(Shellwords::from(":open").ends_with_whitespace(), false);
+    /// #[cfg(unix)]
+    /// assert_eq!(Shellwords::from(":open a\\ ").ends_with_whitespace(), false);
+    /// #[cfg(unix)]
+    /// assert_eq!(Shellwords::from(":open a\\ b.txt").ends_with_whitespace(), false);
+    /// ```
+    pub fn ends_with_whitespace(&self) -> bool {
+        matches!(self.state, State::OnWhitespace)
+    }
+
+    /// Returns the list of shellwords calculated from the input string.
+    pub fn words(&self) -> &[Cow<'a, str>] {
+        &self.words
+    }
+
+    /// Returns a list of strings which correspond to [`Self::words`] but represent the original
+    /// text in the input string - including escape characters - without separating whitespace.
+    pub fn parts(&self) -> &[&'a str] {
+        &self.parts
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    #[cfg(windows)]
+    fn test_normal() {
+        let input = r#":o single_word twó wörds \three\ \"with\ escaping\\"#;
+        let shellwords = Shellwords::from(input);
+        let result = shellwords.words().to_vec();
+        let expected = vec![
+            Cow::from(":o"),
+            Cow::from("single_word"),
+            Cow::from("twó"),
+            Cow::from("wörds"),
+            Cow::from("\\three\\"),
+            Cow::from("\\"),
+            Cow::from("with\\ escaping\\\\"),
+        ];
+        // TODO test is_owned and is_borrowed, once they get stabilized.
+        assert_eq!(expected, result);
+    }
+
+    #[test]
+    #[cfg(unix)]
+    fn test_normal() {
+        let input = r#":o single_word twó wörds \three\ \"with\ escaping\\"#;
+        let shellwords = Shellwords::from(input);
+        let result = shellwords.words().to_vec();
+        let expected = vec![
+            Cow::from(":o"),
+            Cow::from("single_word"),
+            Cow::from("twó"),
+            Cow::from("wörds"),
+            Cow::from(r#"three "with escaping\"#),
+        ];
+        // TODO test is_owned and is_borrowed, once they get stabilized.
+        assert_eq!(expected, result);
+    }
+
+    #[test]
+    #[cfg(unix)]
+    fn test_quoted() {
+        let quoted =
+            r#":o 'single_word' 'twó wörds' '' ' ''\three\' \"with\ escaping\\' 'quote incomplete"#;
+        let shellwords = Shellwords::from(quoted);
+        let result = shellwords.words().to_vec();
+        let expected = vec![
+            Cow::from(":o"),
+            Cow::from("single_word"),
+            Cow::from("twó wörds"),
+            Cow::from(r#"three' "with escaping\"#),
+            Cow::from("quote incomplete"),
+        ];
+        assert_eq!(expected, result);
+    }
+
+    #[test]
+    #[cfg(unix)]
+    fn test_dquoted() {
+        let dquoted = r#":o "single_word" "twó wörds" "" "  ""\three\' \"with\ escaping\\" "dquote incomplete"#;
+        let shellwords = Shellwords::from(dquoted);
+        let result = shellwords.words().to_vec();
+        let expected = vec![
+            Cow::from(":o"),
+            Cow::from("single_word"),
+            Cow::from("twó wörds"),
+            Cow::from(r#"three' "with escaping\"#),
+            Cow::from("dquote incomplete"),
+        ];
+        assert_eq!(expected, result);
+    }
+
+    #[test]
+    #[cfg(unix)]
+    fn test_mixed() {
+        let dquoted = r#":o single_word 'twó wörds' "\three\' \"with\ escaping\\""no space before"'and after' $#%^@ "%^&(%^" ')(*&^%''a\\\\\b' '"#;
+        let shellwords = Shellwords::from(dquoted);
+        let result = shellwords.words().to_vec();
+        let expected = vec![
+            Cow::from(":o"),
+            Cow::from("single_word"),
+            Cow::from("twó wörds"),
+            Cow::from("three' \"with escaping\\"),
+            Cow::from("no space before"),
+            Cow::from("and after"),
+            Cow::from("$#%^@"),
+            Cow::from("%^&(%^"),
+            Cow::from(")(*&^%"),
+            Cow::from(r#"a\\b"#),
+            //last ' just changes to quoted but since we dont have anything after it, it should be ignored
+        ];
+        assert_eq!(expected, result);
+    }
+
+    #[test]
+    fn test_lists() {
+        let input =
+            r#":set statusline.center ["file-type","file-encoding"] '["list", "in", "quotes"]'"#;
+        let shellwords = Shellwords::from(input);
+        let result = shellwords.words().to_vec();
+        let expected = vec![
+            Cow::from(":set"),
+            Cow::from("statusline.center"),
+            Cow::from(r#"["file-type","file-encoding"]"#),
+            Cow::from(r#"["list", "in", "quotes"]"#),
+        ];
+        assert_eq!(expected, result);
+    }
+
+    #[test]
+    #[cfg(unix)]
+    fn test_escaping_unix() {
+        assert_eq!(escape("foobar".into()), Cow::Borrowed("foobar"));
+        assert_eq!(escape("foo bar".into()), Cow::Borrowed("foo\\ bar"));
+        assert_eq!(escape("foo\tbar".into()), Cow::Borrowed("foo\\\tbar"));
+    }
+
+    #[test]
+    #[cfg(windows)]
+    fn test_escaping_windows() {
+        assert_eq!(escape("foobar".into()), Cow::Borrowed("foobar"));
+        assert_eq!(escape("foo bar".into()), Cow::Borrowed("\"foo bar\""));
+    }
+
+    #[test]
+    #[cfg(unix)]
+    fn test_parts() {
+        assert_eq!(Shellwords::from(":o a").parts(), &[":o", "a"]);
+        assert_eq!(Shellwords::from(":o a\\ ").parts(), &[":o", "a\\ "]);
+    }
+
+    #[test]
+    #[cfg(windows)]
+    fn test_parts() {
+        assert_eq!(Shellwords::from(":o a").parts(), &[":o", "a"]);
+        assert_eq!(Shellwords::from(":o a\\ ").parts(), &[":o", "a\\"]);
+    }
+
+    #[test]
+    fn test_multibyte_at_end() {
+        assert_eq!(Shellwords::from("𒀀").parts(), &["𒀀"]);
+        assert_eq!(
+            Shellwords::from(":sh echo 𒀀").parts(),
+            &[":sh", "echo", "𒀀"]
+        );
+        assert_eq!(
+            Shellwords::from(":sh echo 𒀀 hello world𒀀").parts(),
+            &[":sh", "echo", "𒀀", "hello", "world𒀀"]
+        );
+    }
+}

helix-core/src/state.rs

@@ -1,41 +0,0 @@
-use crate::{Rope, Selection};
-
-/// A state represents the current editor state of a single buffer.
-#[derive(Clone)]
-pub struct State {
-    pub doc: Rope,
-    pub selection: Selection,
-}
-
-impl State {
-    #[must_use]
-    pub fn new(doc: Rope) -> Self {
-        Self {
-            doc,
-            selection: Selection::point(0),
-        }
-    }
-
-    // update/transact:
-    // update(desc) => transaction ?  transaction.doc() for applied doc
-    // transaction.apply(doc)
-    // doc.transact(fn -> ... end)
-
-    // replaceSelection (transaction that replaces selection)
-    // changeByRange
-    // changes
-    // slice
-    //
-    // getters:
-    // tabSize
-    // indentUnit
-    // languageDataAt()
-    //
-    // config:
-    // indentation
-    // tabSize
-    // lineUnit
-    // syntax
-    // foldable
-    // changeFilter/transactionFilter
-}

helix-core/src/surround.rs

@@ -0,0 +1,407 @@
+use std::fmt::Display;
+
+use crate::{movement::Direction, search, Range, Selection};
+use ropey::RopeSlice;
+
+pub const PAIRS: &[(char, char)] = &[
+    ('(', ')'),
+    ('[', ']'),
+    ('{', '}'),
+    ('<', '>'),
+    ('«', '»'),
+    ('「', '」'),
+    ('（', '）'),
+];
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum Error {
+    PairNotFound,
+    CursorOverlap,
+    RangeExceedsText,
+    CursorOnAmbiguousPair,
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(match *self {
+            Error::PairNotFound => "Surround pair not found around all cursors",
+            Error::CursorOverlap => "Cursors overlap for a single surround pair range",
+            Error::RangeExceedsText => "Cursor range exceeds text length",
+            Error::CursorOnAmbiguousPair => "Cursor on ambiguous surround pair",
+        })
+    }
+}
+
+type Result<T> = std::result::Result<T, Error>;
+
+/// Given any char in [PAIRS], return the open and closing chars. If not found in
+/// [PAIRS] return (ch, ch).
+///
+/// ```
+/// use helix_core::surround::get_pair;
+///
+/// assert_eq!(get_pair('['), ('[', ']'));
+/// assert_eq!(get_pair('}'), ('{', '}'));
+/// assert_eq!(get_pair('"'), ('"', '"'));
+/// ```
+pub fn get_pair(ch: char) -> (char, char) {
+    PAIRS
+        .iter()
+        .find(|(open, close)| *open == ch || *close == ch)
+        .copied()
+        .unwrap_or((ch, ch))
+}
+
+pub fn find_nth_closest_pairs_pos(
+    text: RopeSlice,
+    range: Range,
+    mut skip: usize,
+) -> Result<(usize, usize)> {
+    let is_open_pair = |ch| PAIRS.iter().any(|(open, _)| *open == ch);
+    let is_close_pair = |ch| PAIRS.iter().any(|(_, close)| *close == ch);
+
+    let mut stack = Vec::with_capacity(2);
+    let pos = range.from();
+    let mut close_pos = pos.saturating_sub(1);
+
+    for ch in text.chars_at(pos) {
+        close_pos += 1;
+
+        if is_open_pair(ch) {
+            // Track open pairs encountered so that we can step over
+            // the corresponding close pairs that will come up further
+            // down the loop. We want to find a lone close pair whose
+            // open pair is before the cursor position.
+            stack.push(ch);
+            continue;
+        }
+
+        if !is_close_pair(ch) {
+            // We don't care if this character isn't a brace pair item,
+            // so short circuit here.
+            continue;
+        }
+
+        let (open, close) = get_pair(ch);
+
+        if stack.last() == Some(&open) {
+            // If we are encountering the closing pair for an opener
+            // we just found while traversing, then its inside the
+            // selection and should be skipped over.
+            stack.pop();
+            continue;
+        }
+
+        match find_nth_open_pair(text, open, close, close_pos, 1) {
+            // Before we accept this pair, we want to ensure that the
+            // pair encloses the range rather than just the cursor.
+            Some(open_pos)
+                if open_pos <= pos.saturating_add(1)
+                    && close_pos >= range.to().saturating_sub(1) =>
+            {
+                // Since we have special conditions for when to
+                // accept, we can't just pass the skip parameter on
+                // through to the find_nth_*_pair methods, so we
+                // track skips manually here.
+                if skip > 1 {
+                    skip -= 1;
+                    continue;
+                }
+
+                return match range.direction() {
+                    Direction::Forward => Ok((open_pos, close_pos)),
+                    Direction::Backward => Ok((close_pos, open_pos)),
+                };
+            }
+            _ => continue,
+        }
+    }
+
+    Err(Error::PairNotFound)
+}
+
+/// Find the position of surround pairs of `ch` which can be either a closing
+/// or opening pair. `n` will skip n - 1 pairs (eg. n=2 will discard (only)
+/// the first pair found and keep looking)
+pub fn find_nth_pairs_pos(
+    text: RopeSlice,
+    ch: char,
+    range: Range,
+    n: usize,
+) -> Result<(usize, usize)> {
+    if text.len_chars() < 2 {
+        return Err(Error::PairNotFound);
+    }
+    if range.to() >= text.len_chars() {
+        return Err(Error::RangeExceedsText);
+    }
+
+    let (open, close) = get_pair(ch);
+    let pos = range.cursor(text);
+
+    let (open, close) = if open == close {
+        if Some(open) == text.get_char(pos) {
+            // Cursor is directly on match char. We return no match
+            // because there's no way to know which side of the char
+            // we should be searching on.
+            return Err(Error::CursorOnAmbiguousPair);
+        }
+        (
+            search::find_nth_prev(text, open, pos, n),
+            search::find_nth_next(text, close, pos, n),
+        )
+    } else {
+        (
+            find_nth_open_pair(text, open, close, pos, n),
+            find_nth_close_pair(text, open, close, pos, n),
+        )
+    };
+
+    Option::zip(open, close).ok_or(Error::PairNotFound)
+}
+
+fn find_nth_open_pair(
+    text: RopeSlice,
+    open: char,
+    close: char,
+    mut pos: usize,
+    n: usize,
+) -> Option<usize> {
+    let mut chars = text.chars_at(pos + 1);
+
+    // Adjusts pos for the first iteration, and handles the case of the
+    // cursor being *on* the close character which will get falsely stepped over
+    // if not skipped here
+    if chars.prev()? == open {
+        return Some(pos);
+    }
+
+    for _ in 0..n {
+        let mut step_over: usize = 0;
+
+        loop {
+            let c = chars.prev()?;
+            pos = pos.saturating_sub(1);
+
+            // ignore other surround pairs that are enclosed *within* our search scope
+            if c == close {
+                step_over += 1;
+            } else if c == open {
+                if step_over == 0 {
+                    break;
+                }
+
+                step_over = step_over.saturating_sub(1);
+            }
+        }
+    }
+
+    Some(pos)
+}
+
+fn find_nth_close_pair(
+    text: RopeSlice,
+    open: char,
+    close: char,
+    mut pos: usize,
+    n: usize,
+) -> Option<usize> {
+    if pos >= text.len_chars() {
+        return None;
+    }
+
+    let mut chars = text.chars_at(pos);
+
+    if chars.next()? == close {
+        return Some(pos);
+    }
+
+    for _ in 0..n {
+        let mut step_over: usize = 0;
+
+        loop {
+            let c = chars.next()?;
+            pos += 1;
+
+            if c == open {
+                step_over += 1;
+            } else if c == close {
+                if step_over == 0 {
+                    break;
+                }
+
+                step_over = step_over.saturating_sub(1);
+            }
+        }
+    }
+
+    Some(pos)
+}
+
+/// Find position of surround characters around every cursor. Returns None
+/// if any positions overlap. Note that the positions are in a flat Vec.
+/// Use get_surround_pos().chunks(2) to get matching pairs of surround positions.
+/// `ch` can be either closing or opening pair. If `ch` is None, surround pairs
+/// are automatically detected around each cursor (note that this may result
+/// in them selecting different surround characters for each selection).
+pub fn get_surround_pos(
+    text: RopeSlice,
+    selection: &Selection,
+    ch: Option<char>,
+    skip: usize,
+) -> Result<Vec<usize>> {
+    let mut change_pos = Vec::new();
+
+    for &range in selection {
+        let (open_pos, close_pos) = match ch {
+            Some(ch) => find_nth_pairs_pos(text, ch, range, skip)?,
+            None => find_nth_closest_pairs_pos(text, range, skip)?,
+        };
+        if change_pos.contains(&open_pos) || change_pos.contains(&close_pos) {
+            return Err(Error::CursorOverlap);
+        }
+        change_pos.extend_from_slice(&[open_pos, close_pos]);
+    }
+    Ok(change_pos)
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::Range;
+
+    use ropey::Rope;
+    use smallvec::SmallVec;
+
+    #[test]
+    fn test_get_surround_pos() {
+        #[rustfmt::skip]
+        let (doc, selection, expectations) =
+            rope_with_selections_and_expectations(
+                "(some) (chars)\n(newline)",
+                "_ ^  _ _ ^   _\n_    ^  _"
+            );
+
+        assert_eq!(
+            get_surround_pos(doc.slice(..), &selection, Some('('), 1).unwrap(),
+            expectations
+        );
+    }
+
+    #[test]
+    fn test_get_surround_pos_bail_different_surround_chars() {
+        #[rustfmt::skip]
+        let (doc, selection, _) =
+            rope_with_selections_and_expectations(
+                "[some]\n(chars)xx\n(newline)",
+                "  ^   \n  ^      \n         "
+            );
+
+        assert_eq!(
+            get_surround_pos(doc.slice(..), &selection, Some('('), 1),
+            Err(Error::PairNotFound)
+        );
+    }
+
+    #[test]
+    fn test_get_surround_pos_bail_overlapping_surround_chars() {
+        #[rustfmt::skip]
+        let (doc, selection, _) =
+            rope_with_selections_and_expectations(
+                "[some]\n(chars)xx\n(newline)",
+                "      \n       ^ \n      ^  "
+            );
+
+        assert_eq!(
+            get_surround_pos(doc.slice(..), &selection, Some('('), 1),
+            Err(Error::PairNotFound) // overlapping surround chars
+        );
+    }
+
+    #[test]
+    fn test_get_surround_pos_bail_cursor_overlap() {
+        #[rustfmt::skip]
+        let (doc, selection, _) =
+            rope_with_selections_and_expectations(
+                "[some]\n(chars)xx\n(newline)",
+                "  ^^  \n         \n         "
+            );
+
+        assert_eq!(
+            get_surround_pos(doc.slice(..), &selection, Some('['), 1),
+            Err(Error::CursorOverlap)
+        );
+    }
+
+    #[test]
+    fn test_find_nth_pairs_pos_quote_success() {
+        #[rustfmt::skip]
+        let (doc, selection, expectations) =
+            rope_with_selections_and_expectations(
+                "some 'quoted text' on this 'line'\n'and this one'",
+                "     _        ^  _               \n              "
+            );
+
+        assert_eq!(2, expectations.len());
+        assert_eq!(
+            find_nth_pairs_pos(doc.slice(..), '\'', selection.primary(), 1)
+                .expect("find should succeed"),
+            (expectations[0], expectations[1])
+        )
+    }
+
+    #[test]
+    fn test_find_nth_pairs_pos_nested_quote_success() {
+        #[rustfmt::skip]
+        let (doc, selection, expectations) =
+            rope_with_selections_and_expectations(
+                "some 'nested 'quoted' text' on this 'line'\n'and this one'",
+                "     _           ^        _               \n              "
+            );
+
+        assert_eq!(2, expectations.len());
+        assert_eq!(
+            find_nth_pairs_pos(doc.slice(..), '\'', selection.primary(), 2)
+                .expect("find should succeed"),
+            (expectations[0], expectations[1])
+        )
+    }
+
+    #[test]
+    fn test_find_nth_pairs_pos_inside_quote_ambiguous() {
+        #[rustfmt::skip]
+        let (doc, selection, _) =
+            rope_with_selections_and_expectations(
+                "some 'nested 'quoted' text' on this 'line'\n'and this one'",
+                "                    ^                     \n              "
+            );
+
+        assert_eq!(
+            find_nth_pairs_pos(doc.slice(..), '\'', selection.primary(), 1),
+            Err(Error::CursorOnAmbiguousPair)
+        )
+    }
+
+    // Create a Rope and a matching Selection using a specification language.
+    // ^ is a single-point selection.
+    // _ is an expected index. These are returned as a Vec<usize> for use in assertions.
+    fn rope_with_selections_and_expectations(
+        text: &str,
+        spec: &str,
+    ) -> (Rope, Selection, Vec<usize>) {
+        if text.len() != spec.len() {
+            panic!("specification must match text length -- are newlines aligned?");
+        }
+
+        let rope = Rope::from(text);
+
+        let selections: SmallVec<[Range; 1]> = spec
+            .match_indices('^')
+            .map(|(i, _)| Range::point(i))
+            .collect();
+
+        let expectations: Vec<usize> = spec.match_indices('_').map(|(i, _)| i).collect();
+
+        (rope, Selection::new(selections, 0), expectations)
+    }
+}