Extension types and rendering

Author: M-J-Hooper

editors/code/package.json

@@ -333,6 +333,11 @@
                     "default": true,
                     "description": "Whether to show inlay type hints"
                 },
+                "rust-analyzer.inlayHints.chainingHints": {
+                    "type": "boolean",
+                    "default": true,
+                    "description": "Whether to show inlay type hints for method chains"
+                },
                 "rust-analyzer.inlayHints.parameterHints": {
                     "type": "boolean",
                     "default": true,

editors/code/src/client.ts

@@ -32,6 +32,7 @@ export async function createClient(config: Config, serverPath: string): Promise<
 
             inlayHintsType: config.inlayHints.typeHints,
             inlayHintsParameter: config.inlayHints.parameterHints,
+            inlayHintsChaining: config.inlayHints.chainingHints,
             inlayHintsMaxLength: config.inlayHints.maxLength,
 
             cargoWatchEnable: cargoWatchOpts.enable,

editors/code/src/config.ts

@@ -88,6 +88,7 @@ export class Config {
         return {
             typeHints: this.cfg.get<boolean>("inlayHints.typeHints")!,
             parameterHints: this.cfg.get<boolean>("inlayHints.parameterHints")!,
+            chainingHints: this.cfg.get<boolean>("inlayHints.chainingHints")!,
             maxLength: this.cfg.get<null | number>("inlayHints.maxLength")!,
         };
     }

editors/code/src/inlay_hints.ts

@@ -10,7 +10,11 @@ export function activateInlayHints(ctx: Ctx) {
     const maybeUpdater = {
         updater: null as null | HintsUpdater,
         onConfigChange() {
-            if (!ctx.config.inlayHints.typeHints && !ctx.config.inlayHints.parameterHints) {
+            if (
+                !ctx.config.inlayHints.typeHints &&
+                !ctx.config.inlayHints.parameterHints &&
+                !ctx.config.inlayHints.chainingHints
+            ) {
                 return this.dispose();
             }
             if (!this.updater) this.updater = new HintsUpdater(ctx);
@@ -63,6 +67,22 @@ const paramHints = {
     }
 };
 
+const chainingHints = {
+    decorationType: vscode.window.createTextEditorDecorationType({
+        after: {
+            color: new vscode.ThemeColor('rust_analyzer.inlayHint'),
+            fontStyle: "normal",
+        }
+    }),
+
+    toDecoration(hint: ra.InlayHint.ChainingHint, conv: lc.Protocol2CodeConverter): vscode.DecorationOptions {
+        return {
+            range: conv.asRange(hint.range),
+            renderOptions: { after: { contentText: ` ${hint.label}` } }
+        };
+    }
+};
+
 class HintsUpdater implements Disposable {
     private sourceFiles = new Map<string, RustSourceFile>(); // map Uri -> RustSourceFile
     private readonly disposables: Disposable[] = [];
@@ -95,7 +115,7 @@ class HintsUpdater implements Disposable {
 
     dispose() {
         this.sourceFiles.forEach(file => file.inlaysRequest?.cancel());
-        this.ctx.visibleRustEditors.forEach(editor => this.renderDecorations(editor, { param: [], type: [] }));
+        this.ctx.visibleRustEditors.forEach(editor => this.renderDecorations(editor, { param: [], type: [], chaining: [] }));
         this.disposables.forEach(d => d.dispose());
     }
 
@@ -154,10 +174,11 @@ class HintsUpdater implements Disposable {
     private renderDecorations(editor: RustEditor, decorations: InlaysDecorations) {
         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 decorations: InlaysDecorations = { type: [], param: [] };
+        const decorations: InlaysDecorations = { type: [], param: [], chaining: [] };
         const conv = this.ctx.client.protocol2CodeConverter;
 
         for (const hint of hints) {
@@ -170,6 +191,10 @@ class HintsUpdater implements Disposable {
                     decorations.param.push(paramHints.toDecoration(hint, conv));
                     continue;
                 }
+                case ra.InlayHint.Kind.ChainingHint: {
+                    decorations.chaining.push(chainingHints.toDecoration(hint, conv));
+                    continue;
+                }
             }
         }
         return decorations;
@@ -196,6 +221,7 @@ class HintsUpdater implements Disposable {
 interface InlaysDecorations {
     type: vscode.DecorationOptions[];
     param: vscode.DecorationOptions[];
+    chaining: vscode.DecorationOptions[];
 }
 
 interface RustSourceFile {

editors/code/src/rust-analyzer-api.ts

@@ -86,19 +86,21 @@ export interface Runnable {
 }
 export const runnables = request<RunnablesParams, Vec<Runnable>>("runnables");
 
-export type InlayHint = InlayHint.TypeHint | InlayHint.ParamHint;
+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;