save

crates/ide/src/ide/inlay_hints.rs

@@ -0,0 +1,54 @@
+use syntax::TextSize;
+
+use crate::def::{Expr, ResolveResult};
+use crate::{DefDatabase, FileRange};
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct InlayHint {
+    pub pos: TextSize,
+    pub kind: InlayKind,
+    pub label: String,
+    pub tooltip: String,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum InlayKind {
+    WithHint,
+}
+
+pub(crate) fn inlay_hints(
+    db: &dyn DefDatabase,
+    FileRange { file_id, range }: FileRange,
+) -> Vec<InlayHint> {
+    let src = db.file_content(file_id);
+    let module = db.module(file_id);
+    let source_map = db.source_map(file_id);
+    let nameres = db.name_resolution(file_id);
+    nameres
+        .iter()
+        .filter_map(|(expr, res)| {
+            let ResolveResult::WithExprs(withs) = res else {
+                return None;
+            };
+            let ident_range = source_map.node_for_expr(expr)?.text_range();
+            ident_range.intersect(range)?;
+
+            let label = "^".repeat(withs.len());
+            let tooltip = withs
+                .iter()
+                .rev()
+                .filter_map(|&with_expr| {
+                    let Expr::With(env_expr, _) = module[with_expr] else { unreachable!() };
+                    let range = source_map.node_for_expr(env_expr)?.text_range();
+                    Some(format!("with {};\n", &src[range]))
+                })
+                .collect::<String>();
+            Some(InlayHint {
+                pos: ident_range.start(),
+                kind: InlayKind::WithHint,
+                label,
+                tooltip: format!("```\n{tooltip}\n```"),
+            })
+        })
+        .collect()
+}

crates/ide/src/ide/mod.rs

@@ -5,6 +5,7 @@ mod expand_selection;
 mod goto_definition;
 mod highlight_related;
 mod hover;
+mod inlay_hints;
 mod links;
 mod references;
 mod rename;
@@ -25,6 +26,7 @@ pub use completion::{CompletionItem, CompletionItemKind};
 pub use goto_definition::GotoDefinitionResult;
 pub use highlight_related::HlRelated;
 pub use hover::HoverResult;
+pub use inlay_hints::{InlayHint, InlayKind};
 pub use links::{Link, LinkTarget};
 pub use rename::RenameResult;
 pub use symbol_hierarchy::SymbolTree;
@@ -165,4 +167,8 @@ impl Analysis {
     pub fn highlight_related(&self, fpos: FilePos) -> Cancellable<Vec<HlRelated>> {
         self.with_db(|db| highlight_related::highlight_related(db, fpos).unwrap_or_default())
     }
+
+    pub fn inlay_hints(&self, frange: FileRange) -> Cancellable<Vec<InlayHint>> {
+        self.with_db(|db| inlay_hints::inlay_hints(db, frange))
+    }
 }

crates/ide/src/lib.rs

@@ -11,7 +11,8 @@ mod tests;
 pub use self::ide::{
     Analysis, AnalysisHost, Assist, AssistKind, Cancelled, CompletionItem, CompletionItemKind,
     GotoDefinitionResult, HlKeyword, HlOperator, HlPunct, HlRange, HlRelated, HlTag, HoverResult,
-    Link, LinkTarget, NavigationTarget, RenameResult, RootDatabase, SymbolTree,
+    InlayHint, InlayKind, Link, LinkTarget, NavigationTarget, RenameResult, RootDatabase,
+    SymbolTree,
 };
 pub use base::{
     Change, FileId, FilePos, FileRange, FileSet, InFile, SourceDatabase, SourceRoot, SourceRootId,

crates/nil/Cargo.toml

@@ -11,7 +11,7 @@ ide = { path = "../ide" }
 indexmap = "1.9.1"
 log = "0.4.17"
 lsp-server = "0.6.0"
-lsp-types = "0.93.0"
+lsp-types = { version = "0.93.0", features = ["proposed"] }
 serde = "1.0.140"
 serde_json = "1.0.82"
 text-size = "1.1.0"

crates/nil/src/capabilities.rs

@@ -49,6 +49,7 @@ pub(crate) fn server_capabilities() -> ServerCapabilities {
         }),
         code_action_provider: Some(CodeActionProviderCapability::Simple(true)),
         document_highlight_provider: Some(OneOf::Left(true)),
+        inlay_hint_provider: Some(OneOf::Left(true)),
         ..Default::default()
     }
 }

crates/nil/src/convert.rs

@@ -1,8 +1,10 @@
 use crate::{semantic_tokens, LineMap, LspError, Result, Vfs};
 use ide::{
     Assist, AssistKind, CompletionItem, CompletionItemKind, Diagnostic, FileId, FilePos, FileRange,
-    HlRange, HlRelated, HoverResult, NameKind, Severity, SymbolTree, TextEdit, WorkspaceEdit,
+    HlRange, HlRelated, HoverResult, InlayHint, InlayKind, NameKind, Severity, SymbolTree,
+    TextEdit, WorkspaceEdit,
 };
+use lsp::{InlayHintLabel, InlayHintTooltip};
 use lsp_server::ErrorCode;
 use lsp_types::{
     self as lsp, CodeAction, CodeActionKind, CodeActionOrCommand, DiagnosticRelatedInformation,
@@ -50,10 +52,15 @@ pub(crate) fn to_location(vfs: &Vfs, frange: FileRange) -> Location {
     Location::new(uri, to_range(&line_map, frange.range))
 }
 
+pub(crate) fn to_pos(line_map: &LineMap, pos: TextSize) -> Position {
+    let (line, col) = line_map.line_col_for_pos(pos);
+    Position::new(line, col)
+}
+
 pub(crate) fn to_range(line_map: &LineMap, range: TextRange) -> Range {
-    let (line1, col1) = line_map.line_col_for_pos(range.start());
-    let (line2, col2) = line_map.line_col_for_pos(range.end());
-    Range::new(Position::new(line1, col1), Position::new(line2, col2))
+    let start = to_pos(line_map, range.start());
+    let end = to_pos(line_map, range.end());
+    Range::new(start, end)
 }
 
 pub(crate) fn to_diagnostics(
@@ -166,6 +173,7 @@ pub(crate) fn to_completion_item(line_map: &LineMap, item: CompletionItem) -> ls
         commit_characters: None,
         data: None,
         tags: None,
+        label_details: None,
     }
 }
 
@@ -333,3 +341,21 @@ pub(crate) fn to_document_highlight(
         })
         .collect()
 }
+
+pub(crate) fn to_inlay_hint(line_map: &LineMap, hint: InlayHint) -> lsp::InlayHint {
+    lsp::InlayHint {
+        position: to_pos(line_map, hint.pos),
+        label: InlayHintLabel::String(hint.label),
+        kind: match hint.kind {
+            InlayKind::WithHint => None,
+        },
+        text_edits: None,
+        tooltip: Some(InlayHintTooltip::MarkupContent(MarkupContent {
+            kind: MarkupKind::Markdown,
+            value: hint.tooltip,
+        })),
+        padding_left: None,
+        padding_right: None,
+        data: None,
+    }
+}

crates/nil/src/handler.rs

@@ -4,10 +4,11 @@ use lsp_types::{
     CodeActionParams, CodeActionResponse, CompletionParams, CompletionResponse, Diagnostic,
     DocumentFormattingParams, DocumentHighlight, DocumentHighlightParams, DocumentLink,
     DocumentLinkParams, DocumentSymbolParams, DocumentSymbolResponse, GotoDefinitionParams,
-    GotoDefinitionResponse, Hover, HoverParams, Location, Position, PrepareRenameResponse, Range,
-    ReferenceParams, RenameParams, SelectionRange, SelectionRangeParams, SemanticTokens,
-    SemanticTokensParams, SemanticTokensRangeParams, SemanticTokensRangeResult,
-    SemanticTokensResult, TextDocumentPositionParams, TextEdit, Url, WorkspaceEdit,
+    GotoDefinitionResponse, Hover, HoverParams, InlayHint, InlayHintParams, Location, Position,
+    PrepareRenameResponse, Range, ReferenceParams, RenameParams, SelectionRange,
+    SelectionRangeParams, SemanticTokens, SemanticTokensParams, SemanticTokensRangeParams,
+    SemanticTokensRangeResult, SemanticTokensResult, TextDocumentPositionParams, TextEdit, Url,
+    WorkspaceEdit,
 };
 use std::path::Path;
 use std::process;
@@ -328,3 +329,17 @@ pub(crate) fn document_highlight(
     let ret = convert::to_document_highlight(&line_map, &ret);
     Ok(Some(ret))
 }
+
+pub(crate) fn inlay_hints(
+    snap: StateSnapshot,
+    params: InlayHintParams,
+) -> Result<Option<Vec<InlayHint>>> {
+    let (file, line_map) = convert::from_file(&snap.vfs(), &params.text_document)?;
+    let (_, range) = convert::from_range(&snap.vfs(), file, params.range)?;
+    let hints = snap.analysis.inlay_hints(FileRange::new(file, range))?;
+    let hints = hints
+        .into_iter()
+        .map(|hint| convert::to_inlay_hint(&line_map, hint))
+        .collect();
+    Ok(Some(hints))
+}

crates/nil/src/server.rs

@@ -227,6 +227,7 @@ impl Server {
             .on::<req::DocumentLinkRequest>(handler::document_links)
             .on::<req::CodeActionRequest>(handler::code_action)
             .on::<req::DocumentHighlightRequest>(handler::document_highlight)
+            .on::<req::InlayHintRequest>(handler::inlay_hints)
             .finish();
     }