Speed up parsing many nested brackets

ai · ai · commit 5ca19019495b · 2026-04-26T12:53:38.000Z
diff --git a/lib/tokenize.js b/lib/tokenize.js
@@ -36,6 +36,7 @@ module.exports = function tokenizer(input, options = {}) {
   let pos = 0
   let buffer = []
   let returned = []
+  let lastBadParen = -1
 
   function position() {
     return pos
@@ -127,11 +128,14 @@ module.exports = function tokenizer(input, options = {}) {
           currentToken = ['brackets', css.slice(pos, next + 1), pos, next]
 
           pos = next
+        } else if (pos <= lastBadParen) {
+          currentToken = ['(', '(', pos]
         } else {
           next = css.indexOf(')', pos + 1)
           content = css.slice(pos, next + 1)
 
           if (next === -1 || RE_BAD_BRACKET.test(content)) {
+            lastBadParen = next === -1 ? length : next
             currentToken = ['(', '(', pos]
           } else {
             currentToken = ['brackets', content, pos, next]
diff --git a/test/tokenize.test.js b/test/tokenize.test.js
@@ -87,7 +87,8 @@ test('tokenizes square brackets', () => {
 test('tokenizes complicated brackets', () => {
   run('(())("")(/**/)(\\\\)(\n)(', [
     ['(', '(', 0],
-    ['brackets', '()', 1, 2],
+    ['(', '(', 1],
+    [')', ')', 2],
     [')', ')', 3],
     ['(', '(', 4],
     ['string', '""', 5, 6],
