Transform flow

Author: DmitrySharabin

src/languages/flow.js

@@ -1,35 +1,17 @@
 import { toArray } from '../util/iterables.js';
-import { insertBefore } from '../util/language-util.js';
 import javascript from './javascript.js';
 
 /** @type {import('../types.d.ts').LanguageProto<'flow'>} */
 export default {
 	id: 'flow',
 	base: javascript,
 	grammar ({ base }) {
-		insertBefore(base, 'keyword', {
-			'type': {
-				pattern:
-					/\b(?:[Bb]oolean|Function|[Nn]umber|[Ss]tring|[Ss]ymbol|any|mixed|null|void)\b/,
-				alias: 'class-name',
-			},
-		});
-
-		insertBefore(base, 'operator', {
-			'flow-punctuation': {
-				pattern: /\{\||\|\}/,
-				alias: 'punctuation',
-			},
-		});
-
 		const fnVariable = /** @type {import('../types.d.ts').GrammarToken} */ (
 			base['function-variable']
 		);
 		fnVariable.pattern =
 			/(?!\s)[_$a-z\xA0-\uFFFF](?:(?!\s)[$\w\xA0-\uFFFF])*(?=\s*=\s*(?:function\b|(?:\([^()]*\)(?:\s*:\s*\w+)?|(?!\s)[_$a-z\xA0-\uFFFF](?:(?!\s)[$\w\xA0-\uFFFF])*)\s*=>))/i;
 
-		delete base['parameter'];
-
 		return {
 			'keyword': [
 				{
@@ -41,8 +23,22 @@ export default {
 						/(^|[^$]\B)\$(?:Diff|Enum|Exact|Keys|ObjMap|PropertyType|Record|Shape|Subtype|Supertype|await)\b(?!\$)/,
 					lookbehind: true,
 				},
-				...toArray(base.keyword),
+				...toArray(/** @type {import('../types.d.ts').GrammarTokens} */ (base).keyword),
 			],
+			$insert: {
+				'type': {
+					$before: 'keyword',
+					pattern:
+						/\b(?:[Bb]oolean|Function|[Nn]umber|[Ss]tring|[Ss]ymbol|any|mixed|null|void)\b/,
+					alias: 'class-name',
+				},
+				'flow-punctuation': {
+					$before: 'operator',
+					pattern: /\{\||\|\}/,
+					alias: 'punctuation',
+				},
+			},
+			$delete: ['parameter'],
 		};
 	},
 };