JS: Use StringBuilder when building up type name in JSDoc#19069
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asgerf merged 1 commit intogithub:mainfrom Mar 20, 2025
Merged
JS: Use StringBuilder when building up type name in JSDoc#19069asgerf merged 1 commit intogithub:mainfrom
asgerf merged 1 commit intogithub:mainfrom
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This code was a bit of a performance cringe. It copied every character into a temporary array, copied that into a String, and slow-appended that onto another String. Note that the call to Characters.toChars is redundant here as advance() doesn't return a code point; it returns -1 or a UTF-16 char. The -1 case is checked for before reaching the call, so we can just cast it to a char and use it directly. We use a StringBuilder to accumulate the string. Normally it's faster to track the start/end indices and do a substring(), but that won't work in the JSDoc extractor because of the star-skipping logic in advance().
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Pull Request Overview
This PR improves the performance of type name accumulation in JSDoc extraction by replacing inefficient string concatenation with a StringBuilder.
- Replaces the use of new String(Character.toChars(advance())) with StringBuilder's append((char)advance()).
- Removes redundant conversion of characters via Characters.toChars, directly casting the char returned by advance().
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This code was a bit of a performance cringe. It copied every character into a temporary array, copied that into a String, and slow-appended that onto another String.
Note that the call to Characters.toChars is redundant here as advance() doesn't return a code point; it returns -1 or a UTF-16 char. The -1 case is checked for before reaching the call, so we can just cast it to a char and use it directly.
We use a StringBuilder to accumulate the string. Normally it's faster to track the start/end indices and do a substring(), but that won't work in the JSDoc extractor because of the star-skipping logic in advance().