perf(lexer): skip identifier and number runs#227
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guybedford merged 2 commits intoJul 13, 2026
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On the 3,057 KiB sample corpus, Wasm drops from 15,356.31 to 13,010.46 us per sweep on Node 18.20.8 (-15.28%) and from 11,724.34 to 9,856.69 us on Node 24.18.0 (-15.93%). The asm.js build drops from 15,934.34 to 12,945.57 us on Node 24.18.0 (-18.76%). The fast path adds 379 raw / 105 gzip bytes to the full Wasm binary. Measurements used 1,500 warmup sweeps followed by 9 interleaved trials of 50 sweeps, dropping the best and worst trials.
guybedford
approved these changes
Jul 13, 2026
guybedford
enabled auto-merge (squash)
July 13, 2026 00:58
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Summary
Skip the remainder of identifier and number runs after their first token dispatch, avoiding repeated switch dispatch and
lastTokenPosstores.On the 3,057 KiB sample corpus, Wasm improves from 15,356.31 to 13,010.46 us per sweep on Node 18.20.8 (-15.28%) and from 11,724.34 to 9,856.69 us on Node 24.18.0 (-15.93%). The asm.js build improves from 15,934.34 to 12,945.57 us on Node 24.18.0 (-18.76%). The full Wasm binary grows by 379 raw / 105 gzip bytes.
Test plan