Initial implementation of view-hir command

editors/code/src/commands.ts

@@ -340,6 +340,75 @@ export function syntaxTree(ctx: Ctx): Cmd {
     };
 }
 
+// Opens the virtual file that will show hir
+//
+// The contents of the file come from the `TextDocumentContentProvider`
+export function viewHir(ctx: Ctx): Cmd {
+    const tdcp = new class implements vscode.TextDocumentContentProvider {
+        readonly uri = vscode.Uri.parse('rust-analyzer://viewHir/hir.txt');
+        readonly eventEmitter = new vscode.EventEmitter<vscode.Uri>();
+        constructor() {
+            vscode.workspace.onDidChangeTextDocument(this.onDidChangeTextDocument, this, ctx.subscriptions);
+            vscode.window.onDidChangeActiveTextEditor(this.onDidChangeActiveTextEditor, this, ctx.subscriptions);
+        }
+
+        private onDidChangeTextDocument(event: vscode.TextDocumentChangeEvent) {
+            if (isRustDocument(event.document)) {
+                // We need to order this after language server updates, but there's no API for that.
+                // Hence, good old sleep().
+                void sleep(10).then(() => this.eventEmitter.fire(this.uri));
+            }
+        }
+        private onDidChangeActiveTextEditor(editor: vscode.TextEditor | undefined) {
+            if (editor && isRustEditor(editor)) {
+                this.eventEmitter.fire(this.uri);
+            }
+        }
+
+        provideTextDocumentContent(_uri: vscode.Uri, ct: vscode.CancellationToken): vscode.ProviderResult<string> {
+            const rustEditor = ctx.activeRustEditor;
+            const client = ctx.client;
+            if (!rustEditor || !client) return '';
+
+            const params = {
+                textDocument: client.code2ProtocolConverter.asTextDocumentIdentifier(rustEditor.document),
+                position: client.code2ProtocolConverter.asPosition(
+                    rustEditor.selection.active,
+                ),
+            };
+            return client.sendRequest(ra.viewHir, params, ct);
+        }
+
+        get onDidChange(): vscode.Event<vscode.Uri> {
+            return this.eventEmitter.event;
+        }
+    };
+
+    void new AstInspector(ctx);
+
+    ctx.pushCleanup(vscode.workspace.registerTextDocumentContentProvider('rust-analyzer', tdcp));
+    ctx.pushCleanup(vscode.languages.setLanguageConfiguration("ra_syntax_tree", {
+        brackets: [["[", ")"]],
+    }));
+
+    return async () => {
+        const editor = vscode.window.activeTextEditor;
+        const rangeEnabled = !!editor && !editor.selection.isEmpty;
+
+        const uri = rangeEnabled
+            ? vscode.Uri.parse(`${tdcp.uri.toString()}?range=true`)
+            : tdcp.uri;
+
+        const document = await vscode.workspace.openTextDocument(uri);
+
+        tdcp.eventEmitter.fire(uri);
+
+        void await vscode.window.showTextDocument(document, {
+            viewColumn: vscode.ViewColumn.Two,
+            preserveFocus: true
+        });
+    };
+}
 
 // Opens the virtual file that will show the syntax tree
 //