Merge #11445

11445: Upstream inlay hints r=lnicola a=lnicola

Closes https://github.com/rust-analyzer/rust-analyzer/issues/2797
Closes https://github.com/rust-analyzer/rust-analyzer/issues/3394 (since now resolve the hints for the range given only, not for the whole document. We don't actually resolve anything due to [hard requirement](https://github.com/rust-analyzer/rust-analyzer/pull/11445#issuecomment-1035227434) on label being immutable. Any further heavy actions could go to the `resolve` method that's now available via the official Code API for hints)

Based on `@SomeoneToIgnore's` branch, with a couple of updates:

 - I squashed, more or less successfully, the commits on that branch
 - downloading the `.d.ts` no longer works, but you can get it manually from https://raw.githubusercontent.com/microsoft/vscode/release/1.64/src/vscode-dts/vscode.proposed.inlayHints.d.ts
 - you might need to pass `--enable-proposed-api matklad.rust-analyzer`
 - if I'm reading the definition right, `InlayHintKind` needs to be serialized as a number, not string
 - this doesn't work anyway -- the client-side gets the hints, but they don't display

Co-authored-by: Kirill Bulatov <mail4score@gmail.com>
Co-authored-by: Laurențiu Nicola <lnicola@dend.ro>

crates/ide/src/inlay_hints.rs

@@ -5,7 +5,7 @@ use itertools::Itertools;
 use stdx::to_lower_snake_case;
 use syntax::{
     ast::{self, AstNode, HasArgList, HasName, UnaryOp},
-    match_ast, Direction, NodeOrToken, SmolStr, SyntaxKind, TextRange, T,
+    match_ast, Direction, NodeOrToken, SmolStr, SyntaxKind, SyntaxNode, TextRange, T,
 };
 
 use crate::FileId;
@@ -58,6 +58,7 @@ pub struct InlayHint {
 pub(crate) fn inlay_hints(
     db: &RootDatabase,
     file_id: FileId,
+    range_limit: Option<FileRange>,
     config: &InlayHintsConfig,
 ) -> Vec<InlayHint> {
     let _p = profile::span("inlay_hints");
@@ -65,25 +66,50 @@ pub(crate) fn inlay_hints(
     let file = sema.parse(file_id);
     let file = file.syntax();
 
-    let mut res = Vec::new();
+    let mut hints = Vec::new();
 
-    for node in file.descendants() {
-        if let Some(expr) = ast::Expr::cast(node.clone()) {
-            get_chaining_hints(&mut res, &sema, config, &expr);
-            match expr {
-                ast::Expr::CallExpr(it) => {
-                    get_param_name_hints(&mut res, &sema, config, ast::Expr::from(it));
+    if let Some(range_limit) = range_limit {
+        let range_limit = range_limit.range;
+        match file.covering_element(range_limit) {
+            NodeOrToken::Token(_) => return hints,
+            NodeOrToken::Node(n) => {
+                for node in n
+                    .descendants()
+                    .filter(|descendant| range_limit.contains_range(descendant.text_range()))
+                {
+                    get_hints(&mut hints, &sema, config, node);
                 }
-                ast::Expr::MethodCallExpr(it) => {
-                    get_param_name_hints(&mut res, &sema, config, ast::Expr::from(it));
-                }
-                _ => (),
             }
-        } else if let Some(it) = ast::IdentPat::cast(node.clone()) {
-            get_bind_pat_hints(&mut res, &sema, config, &it);
+        }
+    } else {
+        for node in file.descendants() {
+            get_hints(&mut hints, &sema, config, node);
         }
     }
-    res
+
+    hints
+}
+
+fn get_hints(
+    hints: &mut Vec<InlayHint>,
+    sema: &Semantics<RootDatabase>,
+    config: &InlayHintsConfig,
+    node: SyntaxNode,
+) {
+    if let Some(expr) = ast::Expr::cast(node.clone()) {
+        get_chaining_hints(hints, sema, config, &expr);
+        match expr {
+            ast::Expr::CallExpr(it) => {
+                get_param_name_hints(hints, sema, config, ast::Expr::from(it));
+            }
+            ast::Expr::MethodCallExpr(it) => {
+                get_param_name_hints(hints, sema, config, ast::Expr::from(it));
+            }
+            _ => (),
+        }
+    } else if let Some(it) = ast::IdentPat::cast(node) {
+        get_bind_pat_hints(hints, sema, config, &it);
+    }
 }
 
 fn get_chaining_hints(
@@ -541,6 +567,8 @@ fn get_callable(
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
+    use ide_db::base_db::FileRange;
+    use syntax::{TextRange, TextSize};
     use test_utils::extract_annotations;
 
     use crate::{fixture, inlay_hints::InlayHintsConfig};
@@ -604,7 +632,7 @@ mod tests {
     fn check_with_config(config: InlayHintsConfig, ra_fixture: &str) {
         let (analysis, file_id) = fixture::file(ra_fixture);
         let expected = extract_annotations(&*analysis.file_text(file_id).unwrap());
-        let inlay_hints = analysis.inlay_hints(&config, file_id).unwrap();
+        let inlay_hints = analysis.inlay_hints(&config, file_id, None).unwrap();
         let actual =
             inlay_hints.into_iter().map(|it| (it.range, it.label.to_string())).collect::<Vec<_>>();
         assert_eq!(expected, actual, "\nExpected:\n{:#?}\n\nActual:\n{:#?}", expected, actual);
@@ -613,7 +641,7 @@ mod tests {
     #[track_caller]
     fn check_expect(config: InlayHintsConfig, ra_fixture: &str, expect: Expect) {
         let (analysis, file_id) = fixture::file(ra_fixture);
-        let inlay_hints = analysis.inlay_hints(&config, file_id).unwrap();
+        let inlay_hints = analysis.inlay_hints(&config, file_id, None).unwrap();
         expect.assert_debug_eq(&inlay_hints)
     }
 
@@ -1045,6 +1073,55 @@ fn main() {
         )
     }
 
+    #[test]
+    fn check_hint_range_limit() {
+        let fixture = r#"
+        //- minicore: fn, sized
+        fn foo() -> impl Fn() { loop {} }
+        fn foo1() -> impl Fn(f64) { loop {} }
+        fn foo2() -> impl Fn(f64, f64) { loop {} }
+        fn foo3() -> impl Fn(f64, f64) -> u32 { loop {} }
+        fn foo4() -> &'static dyn Fn(f64, f64) -> u32 { loop {} }
+        fn foo5() -> &'static dyn Fn(&'static dyn Fn(f64, f64) -> u32, f64) -> u32 { loop {} }
+        fn foo6() -> impl Fn(f64, f64) -> u32 + Sized { loop {} }
+        fn foo7() -> *const (impl Fn(f64, f64) -> u32 + Sized) { loop {} }
+
+        fn main() {
+            let foo = foo();
+            let foo = foo1();
+            let foo = foo2();
+            let foo = foo3();
+             // ^^^ impl Fn(f64, f64) -> u32
+            let foo = foo4();
+             // ^^^ &dyn Fn(f64, f64) -> u32
+            let foo = foo5();
+            let foo = foo6();
+            let foo = foo7();
+        }
+        "#;
+        let (analysis, file_id) = fixture::file(fixture);
+        let expected = extract_annotations(&*analysis.file_text(file_id).unwrap());
+        let inlay_hints = analysis
+            .inlay_hints(
+                &InlayHintsConfig {
+                    parameter_hints: false,
+                    type_hints: true,
+                    chaining_hints: false,
+                    hide_named_constructor_hints: false,
+                    max_length: None,
+                },
+                file_id,
+                Some(FileRange {
+                    file_id,
+                    range: TextRange::new(TextSize::from(500), TextSize::from(600)),
+                }),
+            )
+            .unwrap();
+        let actual =
+            inlay_hints.into_iter().map(|it| (it.range, it.label.to_string())).collect::<Vec<_>>();
+        assert_eq!(expected, actual, "\nExpected:\n{:#?}\n\nActual:\n{:#?}", expected, actual);
+    }
+
     #[test]
     fn fn_hints_ptr_rpit_fn_parentheses() {
         check_types(

crates/ide/src/lib.rs

@@ -358,8 +358,9 @@ impl Analysis {
         &self,
         config: &InlayHintsConfig,
         file_id: FileId,
+        range: Option<FileRange>,
     ) -> Cancellable<Vec<InlayHint>> {
-        self.with_db(|db| inlay_hints::inlay_hints(db, file_id, config))
+        self.with_db(|db| inlay_hints::inlay_hints(db, file_id, range, config))
     }
 
     /// Returns the set of folding ranges.

crates/ide/src/static_index.rs

@@ -112,6 +112,7 @@ impl StaticIndex<'_> {
                     max_length: Some(25),
                 },
                 file_id,
+                None,
             )
             .unwrap();
         // hovers

crates/rust-analyzer/src/caps.rs

@@ -115,6 +115,7 @@ pub fn server_capabilities(config: &Config) -> ServerCapabilities {
         experimental: Some(json!({
             "externalDocs": true,
             "hoverRange": true,
+            "inlayHints": true,
             "joinLines": true,
             "matchingBrace": true,
             "moveItem": true,

crates/rust-analyzer/src/handlers.rs

@@ -1318,11 +1318,22 @@ pub(crate) fn handle_inlay_hints(
     params: InlayHintsParams,
 ) -> Result<Vec<InlayHint>> {
     let _p = profile::span("handle_inlay_hints");
-    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let document_uri = &params.text_document.uri;
+    let file_id = from_proto::file_id(&snap, document_uri)?;
     let line_index = snap.file_line_index(file_id)?;
+    let range = params
+        .range
+        .map(|range| {
+            from_proto::file_range(
+                &snap,
+                TextDocumentIdentifier::new(document_uri.to_owned()),
+                range,
+            )
+        })
+        .transpose()?;
     Ok(snap
         .analysis
-        .inlay_hints(&snap.config.inlay_hints(), file_id)?
+        .inlay_hints(&snap.config.inlay_hints(), file_id, range)?
         .into_iter()
         .map(|it| to_proto::inlay_hint(&line_index, it))
         .collect())

crates/rust-analyzer/src/lsp_ext.rs

@@ -233,27 +233,34 @@ pub enum InlayHints {}
 impl Request for InlayHints {
     type Params = InlayHintsParams;
     type Result = Vec<InlayHint>;
-    const METHOD: &'static str = "rust-analyzer/inlayHints";
+    const METHOD: &'static str = "experimental/inlayHints";
 }
 
 #[derive(Serialize, Deserialize, Debug)]
 #[serde(rename_all = "camelCase")]
 pub struct InlayHintsParams {
     pub text_document: TextDocumentIdentifier,
+    pub range: Option<lsp_types::Range>,
 }
 
-#[derive(Debug, PartialEq, Eq, Deserialize, Serialize)]
-pub enum InlayKind {
-    TypeHint,
-    ParameterHint,
-    ChainingHint,
+#[derive(Eq, PartialEq, Debug, Copy, Clone, Serialize, Deserialize)]
+#[serde(transparent)]
+pub struct InlayHintKind(u8);
+
+impl InlayHintKind {
+    pub const TYPE: InlayHintKind = InlayHintKind(1);
+    pub const PARAMETER: InlayHintKind = InlayHintKind(2);
 }
 
 #[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
 pub struct InlayHint {
-    pub range: Range,
-    pub kind: InlayKind,
     pub label: String,
+    pub position: Position,
+    pub kind: Option<InlayHintKind>,
+    pub tooltip: Option<String>,
+    pub padding_left: Option<bool>,
+    pub padding_right: Option<bool>,
 }
 
 pub enum Ssr {}

crates/rust-analyzer/src/to_proto.rs

@@ -416,12 +416,18 @@ pub(crate) fn signature_help(
 pub(crate) fn inlay_hint(line_index: &LineIndex, inlay_hint: InlayHint) -> lsp_ext::InlayHint {
     lsp_ext::InlayHint {
         label: inlay_hint.label.to_string(),
-        range: range(line_index, inlay_hint.range),
-        kind: match inlay_hint.kind {
-            InlayKind::ParameterHint => lsp_ext::InlayKind::ParameterHint,
-            InlayKind::TypeHint => lsp_ext::InlayKind::TypeHint,
-            InlayKind::ChainingHint => lsp_ext::InlayKind::ChainingHint,
+        position: match inlay_hint.kind {
+            InlayKind::ParameterHint => position(line_index, inlay_hint.range.start()),
+            _ => position(line_index, inlay_hint.range.end()),
         },
+        kind: match inlay_hint.kind {
+            InlayKind::ParameterHint => Some(lsp_ext::InlayHintKind::PARAMETER),
+            InlayKind::TypeHint => Some(lsp_ext::InlayHintKind::TYPE),
+            InlayKind::ChainingHint => None,
+        },
+        tooltip: None,
+        padding_left: Some(true),
+        padding_right: Some(true),
     }
 }
 

docs/dev/lsp-extensions.md

@@ -1,5 +1,5 @@
 <!---
-lsp_ext.rs hash: 5b53b92c9f9d6650
+lsp_ext.rs hash: e32fdde032ff6ebc
 
 If you need to change the above hash to make the test pass, please check if you
 need to adjust this doc as well and ping this issue:
@@ -562,11 +562,11 @@ Expands macro call at a given position.
 
 ## Inlay Hints
 
-**Method:** `rust-analyzer/inlayHints`
+**Method:** `experimental/inlayHints`
 
 This request is sent from client to server to render "inlay hints" -- virtual text inserted into editor to show things like inferred types.
 Generally, the client should re-query inlay hints after every modification.
-Note that we plan to move this request to `experimental/inlayHints`, as it is not really Rust-specific, but the current API is not necessary the right one.
+Until it gets upstreamed, this follows the VS Code API.
 Upstream issues: https://github.com/microsoft/language-server-protocol/issues/956 , https://github.com/rust-analyzer/rust-analyzer/issues/2797
 
 **Request:**
@@ -581,9 +581,12 @@ interface InlayHintsParams {
 
 ```typescript
 interface InlayHint {
-    kind: "TypeHint" | "ParameterHint" | "ChainingHint",
-    range: Range,
-    label: string,
+    position: Position;
+    label: string | InlayHintLabelPart[];
+    tooltip?: string | MarkdownString | undefined;
+    kind?: InlayHintKind;
+    paddingLeft?: boolean;
+    paddingRight?: boolean;
 }
 ```
 

editors/code/.gitignore

@@ -3,3 +3,5 @@ node_modules
 server
 .vscode-test/
 *.vsix
+bundle
+vscode.proposed.d.ts

editors/code/package.json

@@ -21,9 +21,9 @@
         "Programming Languages"
     ],
     "engines": {
-        "vscode": "^1.63.0"
+        "vscode": "^1.65.0"
     },
-    "enableProposedApi": true,
+    "enabledApiProposals": [],
     "scripts": {
         "vscode:prepublish": "npm run build-base -- --minify",
         "package": "vsce package -o rust-analyzer.vsix",
@@ -36,18 +36,18 @@
         "test": "node ./out/tests/runTests.js"
     },
     "dependencies": {
-        "vscode-languageclient": "8.0.0-next.8",
+        "vscode-languageclient": "8.0.0-next.12",
         "d3": "^7.3.0",
         "d3-graphviz": "^4.0.0"
     },
     "devDependencies": {
         "@types/node": "~14.17.5",
-        "@types/vscode": "~1.63.0",
+        "@types/vscode": "~1.65.0",
         "@typescript-eslint/eslint-plugin": "^5.10.0",
         "@typescript-eslint/parser": "^5.10.0",
         "@vscode/test-electron": "^2.1.1",
         "esbuild": "^0.14.12",
-        "eslint": "^8.7.0",
+        "eslint": "^8.10.0",
         "tslib": "^2.3.0",
         "typescript": "^4.5.5",
         "typescript-formatter": "^7.2.2",
@@ -298,11 +298,6 @@
                     "default": true,
                     "description": "Whether to show inlay hints."
                 },
-                "rust-analyzer.inlayHints.smallerHints": {
-                    "type": "boolean",
-                    "default": true,
-                    "description": "Whether inlay hints font size should be smaller than editor's font size."
-                },
                 "rust-analyzer.server.path": {
                     "type": [
                         "null",
@@ -1083,78 +1078,6 @@
             }
         ],
         "colors": [
-            {
-                "id": "rust_analyzer.inlayHints.foreground",
-                "description": "Foreground color of inlay hints (is overriden by more specific rust_analyzer.inlayHints.foreground.* configurations)",
-                "defaults": {
-                    "dark": "#A0A0A0F0",
-                    "light": "#747474",
-                    "highContrast": "#BEBEBE"
-                }
-            },
-            {
-                "id": "rust_analyzer.inlayHints.background",
-                "description": "Background color of inlay hints (is overriden by more specific rust_analyzer.inlayHints.background.* configurations)",
-                "defaults": {
-                    "dark": "#11223300",
-                    "light": "#11223300",
-                    "highContrast": "#11223300"
-                }
-            },
-            {
-                "id": "rust_analyzer.inlayHints.foreground.typeHints",
-                "description": "Foreground color of inlay type hints for variables (overrides rust_analyzer.inlayHints.foreground)",
-                "defaults": {
-                    "dark": "rust_analyzer.inlayHints.foreground",
-                    "light": "rust_analyzer.inlayHints.foreground",
-                    "highContrast": "rust_analyzer.inlayHints.foreground"
-                }
-            },
-            {
-                "id": "rust_analyzer.inlayHints.foreground.chainingHints",
-                "description": "Foreground color of inlay type hints for method chains (overrides rust_analyzer.inlayHints.foreground)",
-                "defaults": {
-                    "dark": "rust_analyzer.inlayHints.foreground",
-                    "light": "rust_analyzer.inlayHints.foreground",
-                    "highContrast": "rust_analyzer.inlayHints.foreground"
-                }
-            },
-            {
-                "id": "rust_analyzer.inlayHints.foreground.parameterHints",
-                "description": "Foreground color of function parameter name inlay hints at the call site (overrides rust_analyzer.inlayHints.foreground)",
-                "defaults": {
-                    "dark": "rust_analyzer.inlayHints.foreground",
-                    "light": "rust_analyzer.inlayHints.foreground",
-                    "highContrast": "rust_analyzer.inlayHints.foreground"
-                }
-            },
-            {
-                "id": "rust_analyzer.inlayHints.background.typeHints",
-                "description": "Background color of inlay type hints for variables (overrides rust_analyzer.inlayHints.background)",
-                "defaults": {
-                    "dark": "rust_analyzer.inlayHints.background",
-                    "light": "rust_analyzer.inlayHints.background",
-                    "highContrast": "rust_analyzer.inlayHints.background"
-                }
-            },
-            {
-                "id": "rust_analyzer.inlayHints.background.chainingHints",
-                "description": "Background color of inlay type hints for method chains (overrides rust_analyzer.inlayHints.background)",
-                "defaults": {
-                    "dark": "rust_analyzer.inlayHints.background",
-                    "light": "rust_analyzer.inlayHints.background",
-                    "highContrast": "rust_analyzer.inlayHints.background"
-                }
-            },
-            {
-                "id": "rust_analyzer.inlayHints.background.parameterHints",
-                "description": "Background color of function parameter name inlay hints at the call site (overrides rust_analyzer.inlayHints.background)",
-                "defaults": {
-                    "dark": "rust_analyzer.inlayHints.background",
-                    "light": "rust_analyzer.inlayHints.background",
-                    "highContrast": "rust_analyzer.inlayHints.background"
-                }
-            },
             {
                 "id": "rust_analyzer.syntaxTreeBorder",
                 "description": "Color of the border displayed in the Rust source code for the selected syntax node (see \"Show Syntax Tree\" command)",

editors/code/src/inlay_hints.ts

@@ -1,267 +1,54 @@
-import * as lc from "vscode-languageclient";
 import * as vscode from 'vscode';
 import * as ra from './lsp_ext';
 
 import { Ctx, Disposable } from './ctx';
-import { sendRequestWithRetry, isRustDocument, RustDocument, RustEditor, sleep } from './util';
-
-interface InlayHintStyle {
-    decorationType: vscode.TextEditorDecorationType;
-    toDecoration(hint: ra.InlayHint, conv: lc.Protocol2CodeConverter): vscode.DecorationOptions;
-};
-
-interface InlayHintsStyles {
-    typeHints: InlayHintStyle;
-    paramHints: InlayHintStyle;
-    chainingHints: InlayHintStyle;
-}
-
+import { sendRequestWithRetry, isRustDocument } from './util';
 
 export function activateInlayHints(ctx: Ctx) {
     const maybeUpdater = {
-        updater: null as null | HintsUpdater,
+        hintsProvider: null as Disposable | null,
+        updateHintsEventEmitter: new vscode.EventEmitter<void>(),
+
         async onConfigChange() {
+            this.dispose();
+
             const anyEnabled = ctx.config.inlayHints.typeHints
                 || ctx.config.inlayHints.parameterHints
                 || ctx.config.inlayHints.chainingHints;
             const enabled = ctx.config.inlayHints.enable && anyEnabled;
+            if (!enabled) return;
 
-            if (!enabled) return this.dispose();
-
-            await sleep(100);
-            if (this.updater) {
-                this.updater.updateInlayHintsStyles();
-                this.updater.syncCacheAndRenderHints();
-            } else {
-                this.updater = new HintsUpdater(ctx);
-            }
+            const event = this.updateHintsEventEmitter.event;
+            this.hintsProvider = vscode.languages.registerInlayHintsProvider({ scheme: 'file', language: 'rust' }, new class implements vscode.InlayHintsProvider {
+                onDidChangeInlayHints = event;
+                async provideInlayHints(document: vscode.TextDocument, range: vscode.Range, token: vscode.CancellationToken): Promise<vscode.InlayHint[]> {
+                    const request = { textDocument: { uri: document.uri.toString() }, range: { start: range.start, end: range.end } };
+                    const hints = await sendRequestWithRetry(ctx.client, ra.inlayHints, request, token).catch(_ => null);
+                    if (hints == null) {
+                        return [];
+                    } else {
+                        return hints;
+                    }
+                }
+            });
         },
+
+        onDidChangeTextDocument({ contentChanges, document }: vscode.TextDocumentChangeEvent) {
+            if (contentChanges.length === 0 || !isRustDocument(document)) return;
+            this.updateHintsEventEmitter.fire();
+        },
+
         dispose() {
-            this.updater?.dispose();
-            this.updater = null;
-        }
+            this.hintsProvider?.dispose();
+            this.hintsProvider = null;
+            this.updateHintsEventEmitter.dispose();
+        },
     };
 
     ctx.pushCleanup(maybeUpdater);
 
-    vscode.workspace.onDidChangeConfiguration(
-        maybeUpdater.onConfigChange, maybeUpdater, ctx.subscriptions
-    );
+    vscode.workspace.onDidChangeConfiguration(maybeUpdater.onConfigChange, maybeUpdater, ctx.subscriptions);
+    vscode.workspace.onDidChangeTextDocument(maybeUpdater.onDidChangeTextDocument, maybeUpdater, ctx.subscriptions);
 
     maybeUpdater.onConfigChange().catch(console.error);
 }
-
-function createHintStyle(hintKind: "type" | "parameter" | "chaining", smallerHints: boolean): InlayHintStyle {
-    // U+200C is a zero-width non-joiner to prevent the editor from forming a ligature
-    // between code and type hints
-    const [pos, render] = ({
-        type: ["after", (label: string) => `\u{200c}: ${label}`],
-        parameter: ["before", (label: string) => `${label}: `],
-        chaining: ["after", (label: string) => `\u{200c}: ${label}`],
-    } as const)[hintKind];
-
-    const fg = new vscode.ThemeColor(`rust_analyzer.inlayHints.foreground.${hintKind}Hints`);
-    const bg = new vscode.ThemeColor(`rust_analyzer.inlayHints.background.${hintKind}Hints`);
-    return {
-        decorationType: vscode.window.createTextEditorDecorationType({
-            [pos]: {
-                color: fg,
-                backgroundColor: bg,
-                fontStyle: "normal",
-                fontWeight: "normal",
-                textDecoration: smallerHints ? ";font-size:smaller" : "none",
-            },
-        }),
-        toDecoration(hint: ra.InlayHint, conv: lc.Protocol2CodeConverter): vscode.DecorationOptions {
-            return {
-                range: conv.asRange(hint.range),
-                renderOptions: { [pos]: { contentText: render(hint.label) } }
-            };
-        }
-    };
-}
-
-const smallHintsStyles = {
-    typeHints: createHintStyle("type", true),
-    paramHints: createHintStyle("parameter", true),
-    chainingHints: createHintStyle("chaining", true),
-};
-
-const biggerHintsStyles = {
-    typeHints: createHintStyle("type", false),
-    paramHints: createHintStyle("parameter", false),
-    chainingHints: createHintStyle("chaining", false),
-};
-
-class HintsUpdater implements Disposable {
-    private sourceFiles = new Map<string, RustSourceFile>(); // map Uri -> RustSourceFile
-    private readonly disposables: Disposable[] = [];
-    private pendingDisposeDecorations: undefined | InlayHintsStyles = undefined;
-    private inlayHintsStyles!: InlayHintsStyles;
-
-    constructor(private readonly ctx: Ctx) {
-        vscode.window.onDidChangeVisibleTextEditors(
-            this.onDidChangeVisibleTextEditors,
-            this,
-            this.disposables
-        );
-
-        vscode.workspace.onDidChangeTextDocument(
-            this.onDidChangeTextDocument,
-            this,
-            this.disposables
-        );
-
-        // Set up initial cache shape
-        ctx.visibleRustEditors.forEach(editor => this.sourceFiles.set(
-            editor.document.uri.toString(),
-            {
-                document: editor.document,
-                inlaysRequest: null,
-                cachedDecorations: null
-            }
-        ));
-
-        this.updateInlayHintsStyles();
-        this.syncCacheAndRenderHints();
-    }
-
-    dispose() {
-        this.sourceFiles.forEach(file => file.inlaysRequest?.cancel());
-        this.ctx.visibleRustEditors.forEach(editor => this.renderDecorations(editor, { param: [], type: [], chaining: [] }));
-        this.disposables.forEach(d => d.dispose());
-    }
-
-    onDidChangeTextDocument({ contentChanges, document }: vscode.TextDocumentChangeEvent) {
-        if (contentChanges.length === 0 || !isRustDocument(document)) return;
-        this.syncCacheAndRenderHints();
-    }
-
-    updateInlayHintsStyles() {
-        const inlayHintsStyles = this.ctx.config.inlayHints.smallerHints ? smallHintsStyles : biggerHintsStyles;
-
-        if (inlayHintsStyles !== this.inlayHintsStyles) {
-            this.pendingDisposeDecorations = this.inlayHintsStyles;
-            this.inlayHintsStyles = inlayHintsStyles;
-        }
-    }
-
-    syncCacheAndRenderHints() {
-        this.sourceFiles.forEach((file, uri) => this.fetchHints(file).then(hints => {
-            if (!hints) return;
-
-            file.cachedDecorations = this.hintsToDecorations(hints);
-
-            for (const editor of this.ctx.visibleRustEditors) {
-                if (editor.document.uri.toString() === uri) {
-                    this.renderDecorations(editor, file.cachedDecorations);
-                }
-            }
-        }));
-    }
-
-    onDidChangeVisibleTextEditors() {
-        const newSourceFiles = new Map<string, RustSourceFile>();
-
-        // Rerendering all, even up-to-date editors for simplicity
-        this.ctx.visibleRustEditors.forEach(async editor => {
-            const uri = editor.document.uri.toString();
-            const file = this.sourceFiles.get(uri) ?? {
-                document: editor.document,
-                inlaysRequest: null,
-                cachedDecorations: null
-            };
-            newSourceFiles.set(uri, file);
-
-            // No text documents changed, so we may try to use the cache
-            if (!file.cachedDecorations) {
-                const hints = await this.fetchHints(file);
-                if (!hints) return;
-
-                file.cachedDecorations = this.hintsToDecorations(hints);
-            }
-
-            this.renderDecorations(editor, file.cachedDecorations);
-        });
-
-        // Cancel requests for no longer visible (disposed) source files
-        this.sourceFiles.forEach((file, uri) => {
-            if (!newSourceFiles.has(uri)) file.inlaysRequest?.cancel();
-        });
-
-        this.sourceFiles = newSourceFiles;
-    }
-
-    private renderDecorations(editor: RustEditor, decorations: InlaysDecorations) {
-        const { typeHints, paramHints, chainingHints } = this.inlayHintsStyles;
-        if (this.pendingDisposeDecorations !== undefined) {
-            const { typeHints, paramHints, chainingHints } = this.pendingDisposeDecorations;
-            editor.setDecorations(typeHints.decorationType, []);
-            editor.setDecorations(paramHints.decorationType, []);
-            editor.setDecorations(chainingHints.decorationType, []);
-        }
-        editor.setDecorations(typeHints.decorationType, decorations.type);
-        editor.setDecorations(paramHints.decorationType, decorations.param);
-        editor.setDecorations(chainingHints.decorationType, decorations.chaining);
-    }
-
-    private hintsToDecorations(hints: ra.InlayHint[]): InlaysDecorations {
-        const { typeHints, paramHints, chainingHints } = this.inlayHintsStyles;
-        const decorations: InlaysDecorations = { type: [], param: [], chaining: [] };
-        const conv = this.ctx.client.protocol2CodeConverter;
-
-        for (const hint of hints) {
-            switch (hint.kind) {
-                case ra.InlayHint.Kind.TypeHint: {
-                    decorations.type.push(typeHints.toDecoration(hint, conv));
-                    continue;
-                }
-                case ra.InlayHint.Kind.ParamHint: {
-                    decorations.param.push(paramHints.toDecoration(hint, conv));
-                    continue;
-                }
-                case ra.InlayHint.Kind.ChainingHint: {
-                    decorations.chaining.push(chainingHints.toDecoration(hint, conv));
-                    continue;
-                }
-            }
-        }
-        return decorations;
-    }
-
-    private async fetchHints(file: RustSourceFile): Promise<null | ra.InlayHint[]> {
-        file.inlaysRequest?.cancel();
-
-        const tokenSource = new vscode.CancellationTokenSource();
-        file.inlaysRequest = tokenSource;
-
-        const request = { textDocument: { uri: file.document.uri.toString() } };
-
-        return sendRequestWithRetry(this.ctx.client, ra.inlayHints, request, tokenSource.token)
-            .catch(_ => null)
-            .finally(() => {
-                if (file.inlaysRequest === tokenSource) {
-                    file.inlaysRequest = null;
-                }
-            });
-    }
-}
-
-interface InlaysDecorations {
-    type: vscode.DecorationOptions[];
-    param: vscode.DecorationOptions[];
-    chaining: vscode.DecorationOptions[];
-}
-
-interface RustSourceFile {
-    /**
-     * Source of the token to cancel in-flight inlay hints request if any.
-     */
-    inlaysRequest: null | vscode.CancellationTokenSource;
-    /**
-     * Last applied decorations.
-     */
-    cachedDecorations: null | InlaysDecorations;
-
-    document: RustDocument;
-}

editors/code/src/lsp_ext.ts

@@ -2,6 +2,7 @@
  * This file mirrors `crates/rust-analyzer/src/lsp_ext.rs` declarations.
  */
 
+import { InlayHint } from "vscode";
 import * as lc from "vscode-languageclient";
 
 export interface AnalyzerStatusParams {
@@ -99,26 +100,11 @@ export interface TestInfo {
 
 export const relatedTests = new lc.RequestType<lc.TextDocumentPositionParams, TestInfo[], void>("rust-analyzer/relatedTests");
 
-export type InlayHint = InlayHint.TypeHint | InlayHint.ParamHint | InlayHint.ChainingHint;
-
-export namespace InlayHint {
-    export const enum Kind {
-        TypeHint = "TypeHint",
-        ParamHint = "ParameterHint",
-        ChainingHint = "ChainingHint",
-    }
-    interface Common {
-        range: lc.Range;
-        label: string;
-    }
-    export type TypeHint = Common & { kind: Kind.TypeHint };
-    export type ParamHint = Common & { kind: Kind.ParamHint };
-    export type ChainingHint = Common & { kind: Kind.ChainingHint };
-}
 export interface InlayHintsParams {
     textDocument: lc.TextDocumentIdentifier;
+    range: lc.Range;
 }
-export const inlayHints = new lc.RequestType<InlayHintsParams, InlayHint[], void>("rust-analyzer/inlayHints");
+export const inlayHints = new lc.RequestType<InlayHintsParams, InlayHint[], void>("experimental/inlayHints");
 
 export interface SsrParams {
     query: string;