perf(parser): pre-allocate extends vec with 1 cap

[camc314]

if we hit here, it means that we've seen the extends keyword - having code like class foo extends {} is invalid as there must be at least one extends expression, so min size of the extendsvec will be 1.

This just avoids the re-alloc

[camc314]

• perf(parser): pre-allocate extends vec with 1 cap #20667 👈 (View in Graphite)
• perf(parser): avoid re-allocating when parsing import stmt #20666
• perf(parser): avoid vec clone in parse_heritage_clause #20665
• main

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[Copilot]

Pull request overview

This PR makes a small parser performance tweak by pre-allocating the extends list with capacity 1 in class heritage parsing, avoiding an initial grow on the common single-extends case.

Changes:

• Pre-allocate the extends vector in parse_extends_clause using vec_with_capacity(1) instead of vec().

[codspeed-hq]

Merging this PR will not alter performance

✅ 53 untouched benchmarks
⏩ 3 skipped benchmarks¹

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_{Comparing c/03-23-perf_parser_pre-allocate_extends_vec_with_1_cap (4172d22) with c/03-23-perf_parser_avoid_re-allocating_when_parsing_import_stmt (2cb0cb3)}

Footnotes

1. 3 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[Boshen]

Merge activity

• Mar 24, 4:00 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Mar 24, 4:00 AM UTC: Boshen added this pull request to the Graphite merge queue.
• Mar 24, 4:05 AM UTC: Merged by the Graphite merge queue.