feat(editor): highlight default return modifiers

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2 files changed, 21 insertions, 2 deletions

diff --git a/plugin/syntaxes/cie-pseudocode.tmLanguage.json b/plugin/syntaxes/cie-pseudocode.tmLanguage.json
index 14ef33c..ef8146f 100644
--- a/plugin/syntaxes/cie-pseudocode.tmLanguage.json
+++ b/plugin/syntaxes/cie-pseudocode.tmLanguage.json
@@ -139,12 +139,15 @@
       }
     },
     "return_type": {
-      "match": "(?<!\\w)(RETURNS)\\s+((?<type>[A-Za-z_][A-Za-z0-9_]*(?:\\s*<\\s*\\g<type>(?:\\s*,\\s*\\g<type>)*\\s*>)?(?:\\s*\\.\\.\\.)?))",
+      "match": "(?<!\\w)(RETURNS)\\s+(?:(DEFAULT)\\s+)?((?<type>[A-Za-z_][A-Za-z0-9_]*(?:\\s*<\\s*\\g<type>(?:\\s*,\\s*\\g<type>)*\\s*>)?(?:\\s*\\.\\.\\.)?))",
       "captures": {
         "1": {
           "name": "storage.modifier.cie-pseudocode"
         },
         "2": {
+          "name": "storage.modifier.cpp"
+        },
+        "3": {
           "patterns": [
             {
               "include": "#type_tokens"
@@ -477,7 +480,7 @@
           "name": "keyword.other.operator.overload.cpp"
         },
         {
-          "match": "(?<!\\w)(?:OVERLOAD)(?!\\w)",
+          "match": "(?<!\\w)(?:OVERLOAD|DEFAULT)(?!\\w)",
           "name": "storage.modifier.cpp"
         },
         {
diff --git a/plugin/test/highlighting.test.js b/plugin/test/highlighting.test.js
index 1edac7b..95b10c6 100644
--- a/plugin/test/highlighting.test.js
+++ b/plugin/test/highlighting.test.js
@@ -70,6 +70,22 @@ test('function names include underscores and explicit nested template arguments'
 	assert.equal('_value'.match(new RegExp(configuration.wordPattern))[0], '_value');
 });
 
+test('default return modifiers preserve builtin and nested result type scopes', () => {
+	for (const [text, names] of [
+		['OVERLOAD FUNCTION Foo(X : STRING) RETURNS DEFAULT REAL', ['REAL']],
+		['PUBLIC OVERLOAD FUNCTION Foo() RETURNS DEFAULT Box<Pair<Widget, REAL>>', ['Box', 'Pair', 'Widget', 'REAL']]
+	]) {
+		assert.ok(scopesAt(text, 'DEFAULT').includes('storage.modifier.cpp'));
+		assert.ok(!scopesAt(text, 'DEFAULT').includes('entity.name.type.cpp'));
+		for (const name of names) {
+			assert.ok(scopesAt(text, name).some(s => /^(entity\.name\.type|storage\.type)\./.test(s)), `${text}: ${name}`);
+		}
+	}
+	assert.ok(!scopesAt('OUTPUT "DEFAULT"', 'DEFAULT').includes('storage.modifier.cpp'));
+	assert.ok(!scopesAt('// DEFAULT', 'DEFAULT').includes('storage.modifier.cpp'));
+	assert.ok(!scopesAt('default()', 'default').includes('storage.modifier.cpp'));
+});
+
 test('types are recognized in declarations, signatures, arrays, aliases, constructors and templates', () => {
 	for (const [text, names] of [
 		['TYPE Student', ['Student']],