4 files changed, 54 insertions, 7 deletions

diff --git a/editors/code/language-configuration.json b/editors/code/language-configuration.json
index b20e0d978..382484bc7 100644
--- a/editors/code/language-configuration.json
+++ b/editors/code/language-configuration.json
@@ -23,7 +23,8 @@
         ["(", ")"],
         ["<", ">"],
         ["\"", "\""],
-        ["'", "'"]
+        ["'", "'"],
+        ["|", "|"]
     ],
     "indentationRules": {
         "increaseIndentPattern": "^.*\\{[^}\"']*$|^.*\\([^\\)\"']*$",
diff --git a/editors/code/package.json b/editors/code/package.json
index fa5632f90..97d92e43c 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -653,6 +653,11 @@
                     "default": true,
                     "type": "boolean"
                 },
+                "rust-analyzer.inlayHints.smallerHints": {
+                    "markdownDescription": "Whether inlay hints font size should be smaller than editor's font size.",
+                    "default": true,
+                    "type": "boolean"
+                },
                 "rust-analyzer.lens.debug": {
                     "markdownDescription": "Whether to show `Debug` lens. Only applies when\n`#rust-analyzer.lens.enable#` is set.",
                     "default": true,
diff --git a/editors/code/src/config.ts b/editors/code/src/config.ts
index 82f0a0566..03f7d7cc3 100644
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@@ -115,6 +115,7 @@ export class Config {
             typeHints: this.get<boolean>("inlayHints.typeHints"),
             parameterHints: this.get<boolean>("inlayHints.parameterHints"),
             chainingHints: this.get<boolean>("inlayHints.chainingHints"),
+            smallerHints: this.get<boolean>("inlayHints.smallerHints"),
             maxLength: this.get<null | number>("inlayHints.maxLength"),
         };
     }
diff --git a/editors/code/src/inlay_hints.ts b/editors/code/src/inlay_hints.ts
index 61db6b8d0..c23d6f738 100644
--- a/editors/code/src/inlay_hints.ts
+++ b/editors/code/src/inlay_hints.ts
@@ -5,6 +5,17 @@ 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;
+}
+
 
 export function activateInlayHints(ctx: Ctx) {
     const maybeUpdater = {
@@ -19,6 +30,7 @@ export function activateInlayHints(ctx: Ctx) {
 
             await sleep(100);
             if (this.updater) {
+                this.updater.updateInlayHintsStyles();
                 this.updater.syncCacheAndRenderHints();
             } else {
                 this.updater = new HintsUpdater(ctx);
@@ -39,11 +51,7 @@ export function activateInlayHints(ctx: Ctx) {
     maybeUpdater.onConfigChange().catch(console.error);
 }
 
-const typeHints = createHintStyle("type");
-const paramHints = createHintStyle("parameter");
-const chainingHints = createHintStyle("chaining");
-
-function createHintStyle(hintKind: "type" | "parameter" | "chaining") {
+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] = ({
@@ -61,7 +69,7 @@ function createHintStyle(hintKind: "type" | "parameter" | "chaining") {
                 backgroundColor: bg,
                 fontStyle: "normal",
                 fontWeight: "normal",
-                textDecoration: ";font-size:smaller",
+                textDecoration: smallerHints ? ";font-size:smaller" : "none",
             },
         }),
         toDecoration(hint: ra.InlayHint, conv: lc.Protocol2CodeConverter): vscode.DecorationOptions {
@@ -73,9 +81,23 @@ function createHintStyle(hintKind: "type" | "parameter" | "chaining") {
     };
 }
 
+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(
@@ -100,6 +122,7 @@ class HintsUpdater implements Disposable {
             }
         ));
 
+        this.updateInlayHintsStyles();
         this.syncCacheAndRenderHints();
     }
 
@@ -114,6 +137,15 @@ class HintsUpdater implements Disposable {
         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;
@@ -161,12 +193,20 @@ class HintsUpdater implements Disposable {
     }
 
     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;