Merge #924

924: Improve show syntax tree r=matklad a=vipentti

This implements some of the features discussed in #820. 

You can now select a range of syntax in a file and then use "Show Syntax Tree" to show its syntax. In addition you can select a range of syntax that is inside a string (typically test cases) and show its syntax as well.

Previous behavior is still available, simply use "Show Syntax Tree" without a selection, and you get the live updating syntax tree. Additionally now the live updating tree will update when the active file is changed. Previously you had to type something in the new file to get the syntax tree to update.

Co-authored-by: Ville Penttinen <[email protected]>

5 files changed, 75 insertions, 38 deletions

diff --git a/editors/code/package.json b/editors/code/package.json
index d4ce2ae2c..fda411810 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -75,7 +75,7 @@
         "commands": [
             {
                 "command": "rust-analyzer.syntaxTree",
-                "title": "Show syntax tree for current file",
+                "title": "Show Syntax Tree",
                 "category": "Rust Analyzer"
             },
             {
diff --git a/editors/code/src/commands/syntaxTree.ts b/editors/code/src/commands/syntaxTree.ts
index c0baf08c5..2f50fe14b 100644
--- a/editors/code/src/commands/syntaxTree.ts
+++ b/editors/code/src/commands/syntaxTree.ts
@@ -1,11 +1,11 @@
 import * as vscode from 'vscode';
-import { TextDocumentIdentifier } from 'vscode-languageclient';
+import { Range, TextDocumentIdentifier } from 'vscode-languageclient';
 
 import { Server } from '../server';
 
 export const syntaxTreeUri = vscode.Uri.parse('rust-analyzer://syntaxtree');
 
-export class TextDocumentContentProvider
+export class SyntaxTreeContentProvider
     implements vscode.TextDocumentContentProvider {
     public eventEmitter = new vscode.EventEmitter<vscode.Uri>();
     public syntaxTree: string = 'Not available';
@@ -17,8 +17,21 @@ export class TextDocumentContentProvider
         if (editor == null) {
             return '';
         }
+
+        let range: Range | undefined;
+
+        // When the range based query is enabled we take the range of the selection
+        if (uri.query === 'range=true') {
+            range = editor.selection.isEmpty
+                ? undefined
+                : Server.client.code2ProtocolConverter.asRange(
+                      editor.selection
+                  );
+        }
+
         const request: SyntaxTreeParams = {
-            textDocument: { uri: editor.document.uri.toString() }
+            textDocument: { uri: editor.document.uri.toString() },
+            range
         };
         return Server.client.sendRequest<SyntaxTreeResult>(
             'rust-analyzer/syntaxTree',
@@ -33,6 +46,7 @@ export class TextDocumentContentProvider
 
 interface SyntaxTreeParams {
     textDocument: TextDocumentIdentifier;
+    range?: Range;
 }
 
 type SyntaxTreeResult = string;
@@ -40,11 +54,23 @@ type SyntaxTreeResult = string;
 // Opens the virtual file that will show the syntax tree
 //
 // The contents of the file come from the `TextDocumentContentProvider`
-export async function handle() {
-    const document = await vscode.workspace.openTextDocument(syntaxTreeUri);
-    return vscode.window.showTextDocument(
-        document,
-        vscode.ViewColumn.Two,
-        true
-    );
+export function createHandle(provider: SyntaxTreeContentProvider) {
+    return async () => {
+        const editor = vscode.window.activeTextEditor;
+        const rangeEnabled = !!(editor && !editor.selection.isEmpty);
+
+        const uri = rangeEnabled
+            ? vscode.Uri.parse(`${syntaxTreeUri.toString()}?range=true`)
+            : syntaxTreeUri;
+
+        const document = await vscode.workspace.openTextDocument(uri);
+
+        provider.eventEmitter.fire(uri);
+
+        return vscode.window.showTextDocument(
+            document,
+            vscode.ViewColumn.Two,
+            true
+        );
+    };
 }
diff --git a/editors/code/src/events/change_active_text_editor.ts b/editors/code/src/events/change_active_text_editor.ts
index af295b2ec..64be56225 100644
--- a/editors/code/src/events/change_active_text_editor.ts
+++ b/editors/code/src/events/change_active_text_editor.ts
@@ -1,23 +1,32 @@
 import { TextEditor } from 'vscode';
 import { TextDocumentIdentifier } from 'vscode-languageclient';
 
+import {
+    SyntaxTreeContentProvider,
+    syntaxTreeUri
+} from '../commands/syntaxTree';
 import { Decoration } from '../highlighting';
 import { Server } from '../server';
 
-export async function handle(editor: TextEditor | undefined) {
-    if (
-        !Server.config.highlightingOn ||
-        !editor ||
-        editor.document.languageId !== 'rust'
-    ) {
-        return;
-    }
-    const params: TextDocumentIdentifier = {
-        uri: editor.document.uri.toString()
+export function makeHandler(syntaxTreeProvider: SyntaxTreeContentProvider) {
+    return async function handle(editor: TextEditor | undefined) {
+        if (!editor || editor.document.languageId !== 'rust') {
+            return;
+        }
+
+        syntaxTreeProvider.eventEmitter.fire(syntaxTreeUri);
+
+        if (!Server.config.highlightingOn) {
+            return;
+        }
+
+        const params: TextDocumentIdentifier = {
+            uri: editor.document.uri.toString()
+        };
+        const decorations = await Server.client.sendRequest<Decoration[]>(
+            'rust-analyzer/decorationsRequest',
+            params
+        );
+        Server.highlighter.setHighlights(editor, decorations);
     };
-    const decorations = await Server.client.sendRequest<Decoration[]>(
-        'rust-analyzer/decorationsRequest',
-        params
-    );
-    Server.highlighter.setHighlights(editor, decorations);
 }
diff --git a/editors/code/src/events/change_text_document.ts b/editors/code/src/events/change_text_document.ts
index 6be057245..89488bc61 100644
--- a/editors/code/src/events/change_text_document.ts
+++ b/editors/code/src/events/change_text_document.ts
@@ -1,20 +1,18 @@
 import * as vscode from 'vscode';
 
 import {
-    syntaxTreeUri,
-    TextDocumentContentProvider
+    SyntaxTreeContentProvider,
+    syntaxTreeUri
 } from '../commands/syntaxTree';
 
-export function createHandler(
-    textDocumentContentProvider: TextDocumentContentProvider
-) {
+export function createHandler(syntaxTreeProvider: SyntaxTreeContentProvider) {
     return (event: vscode.TextDocumentChangeEvent) => {
         const doc = event.document;
         if (doc.languageId !== 'rust') {
             return;
         }
         afterLs(() => {
-            textDocumentContentProvider.eventEmitter.fire(syntaxTreeUri);
+            syntaxTreeProvider.eventEmitter.fire(syntaxTreeUri);
         });
     };
 }
diff --git a/editors/code/src/extension.ts b/editors/code/src/extension.ts
index 8b332eeb2..941beba18 100644
--- a/editors/code/src/extension.ts
+++ b/editors/code/src/extension.ts
@@ -2,7 +2,7 @@ import * as vscode from 'vscode';
 import * as lc from 'vscode-languageclient';
 
 import * as commands from './commands';
-import { TextDocumentContentProvider } from './commands/syntaxTree';
+import { SyntaxTreeContentProvider } from './commands/syntaxTree';
 import * as events from './events';
 import * as notifications from './notifications';
 import { Server } from './server';
@@ -52,7 +52,6 @@ export function activate(context: vscode.ExtensionContext) {
     registerCommand('rust-analyzer.collectGarbage', () =>
         Server.client.sendRequest<null>('rust-analyzer/collectGarbage', null)
     );
-    registerCommand('rust-analyzer.syntaxTree', commands.syntaxTree.handle);
     registerCommand(
         'rust-analyzer.extendSelection',
         commands.extendSelection.handle
@@ -95,22 +94,27 @@ export function activate(context: vscode.ExtensionContext) {
             notifications.publishDecorations.handle
         ]
     ];
+    const syntaxTreeContentProvider = new SyntaxTreeContentProvider();
 
     // The events below are plain old javascript events, triggered and handled by vscode
     vscode.window.onDidChangeActiveTextEditor(
-        events.changeActiveTextEditor.handle
+        events.changeActiveTextEditor.makeHandler(syntaxTreeContentProvider)
     );
 
-    const textDocumentContentProvider = new TextDocumentContentProvider();
     disposeOnDeactivation(
         vscode.workspace.registerTextDocumentContentProvider(
             'rust-analyzer',
-            textDocumentContentProvider
+            syntaxTreeContentProvider
         )
     );
 
+    registerCommand(
+        'rust-analyzer.syntaxTree',
+        commands.syntaxTree.createHandle(syntaxTreeContentProvider)
+    );
+
     vscode.workspace.onDidChangeTextDocument(
-        events.changeTextDocument.createHandler(textDocumentContentProvider),
+        events.changeTextDocument.createHandler(syntaxTreeContentProvider),
         null,
         context.subscriptions
     );