VS Code: decoration-based matching, Ctrl+K bindings, README overhaul (from dev f8451715e657)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tst/editor/vscode_ext_test.js

@@ -59,7 +59,8 @@ class WorkspaceEdit {
     replace(uri, range, newText) { this.edits.push({ uri, range, newText }); }
 }
 
-const listeners = { open: [], change: [], close: [] };
+const listeners = { open: [], change: [], close: [], selection: [] };
+const decorationTypes = [];              // in creation order: match, mismatch
 const providers = {};
 const commands = {};
 const collections = {};
@@ -87,10 +88,20 @@ const vscodeStub = {
         onDidCloseTextDocument: (fn) => { listeners.close.push(fn); return { dispose() {} }; },
         applyEdit: (we) => { appliedEdits.push(we); return Promise.resolve(true); },
     },
+    ThemeColor: class ThemeColor {
+        constructor(id) { this.id = id; }
+    },
     window: {
         createOutputChannel: () => ({ append() {}, dispose() {} }),
         showWarningMessage: (m) => { statusMessages.push(m); },
         setStatusBarMessage: (m) => { statusMessages.push(m); },
+        createTextEditorDecorationType: (opts) => {
+            const t = { opts, dispose() {} };
+            decorationTypes.push(t);
+            return t;
+        },
+        onDidChangeTextEditorSelection: (fn) => { listeners.selection.push(fn); return { dispose() {} }; },
+        onDidChangeActiveTextEditor: () => ({ dispose() {} }),
         activeTextEditor: null,
     },
     languages: {
@@ -199,6 +210,27 @@ async function main() {
     check('jumpToMatch cursor at close', sel.active.character === 7,
           JSON.stringify(sel));
 
+    // live decorations: a bare close highlights its pair from any position.
+    const [matchType, mismatchType] = decorationTypes;
+    const editor = vscodeStub.window.activeTextEditor;
+    editor.decorations = new Map();
+    editor.setDecorations = (type, ranges) => editor.decorations.set(type, ranges);
+    editor.selection = new Selection(new Position(0, 7), new Position(0, 7));
+    listeners.selection.forEach((fn) => fn({ textEditor: editor }));
+    await waitFor(() => (editor.decorations.get(matchType) || []).length === 2,
+                  'match decorations');
+    check('decorations: bare close boxes the pair', true);
+
+    // mismatch: red decoration type, match type cleared
+    setDocText('@ol x ul@\n');
+    editor.selection = new Selection(new Position(0, 0), new Position(0, 0));
+    listeners.selection.forEach((fn) => fn({ textEditor: editor }));
+    await waitFor(() => (editor.decorations.get(mismatchType) || []).length === 2,
+                  'mismatch decorations');
+    check('decorations: mismatch in the red type',
+          (editor.decorations.get(matchType) || []).length === 0,
+          JSON.stringify([...editor.decorations.values()]));
+
     // alignTable round-trips through workspace/applyEdit.
     const src = fs.readFileSync(path.join(fixDir, 'align_mixed.kt'), 'utf8');
     const exp = fs.readFileSync(path.join(fixDir, 'align_mixed_expected.kt'), 'utf8');