perf(parser): cache cur_kind() to eliminate redundant calls #14411
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Pull Request Overview
Performance optimization to reduce redundant token kind extraction in parser hot paths by caching cur_kind() results before compound conditional checks.
- Cache
cur_kind()in local variables to eliminate redundant calls in compound boolean expressions - Inline
has_fatal_error()logic to avoid duplicatecur_kind()calls - Convert
self.at(Kind::X)patterns to direct kind comparisons where appropriate
Reviewed Changes
Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.
| File | Description |
|---|---|
| crates/oxc_parser/src/ts/types.rs | Cache kind for 3 compound checks to reduce redundant token extraction |
| crates/oxc_parser/src/js/module.rs | Cache kind for import statement parsing optimization |
| crates/oxc_parser/src/js/arrow.rs | Cache kind for arrow function parameter detection |
| crates/oxc_parser/src/cursor.rs | Inline fatal error checks and cache kind in hot parsing loop |
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CodSpeed Performance ReportMerging #14411 will not alter performanceComparing Summary
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## Summary Optimization to reduce redundant token kind extraction in hot paths by caching `cur_kind()` results before compound checks. ## Problem - Compound checks like `self.at(X) || self.at(Y)` call `cur_kind()` twice - Pattern `self.at(close) || self.has_fatal_error()` calls `cur_kind()` twice since `has_fatal_error()` internally calls it - Token kind extraction involves bit-packing operations: `((self.0 >> 64) & 0xFF) as u8` ## Solution Cache `cur_kind()` in a local variable before compound checks to eliminate redundant calls. ## Changes - **`cursor.rs:parse_delimited_list()`**: Hot loop parsing arrays, objects, parameters - reduced from 2-3 calls per iteration to 1 - **`arrow.rs:68`**: Cached kind for `LParen`/`LAngle` check - **`module.rs:101`**: Cached kind for `LCurly`/`Star` check - **`types.rs`**: Fixed 3 locations (lines 91, 558, 1188) with double `at()` calls ## Impact Every JavaScript array, object literal, function parameter list, and TypeScript type now extracts the token kind fewer times during parsing. 🤖 Generated with [Claude Code](https://claude.com/claude-code)
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## Summary Optimization to reduce redundant token kind extraction in hot paths by caching `cur_kind()` results before compound checks. ## Problem - Compound checks like `self.at(X) || self.at(Y)` call `cur_kind()` twice - Pattern `self.at(close) || self.has_fatal_error()` calls `cur_kind()` twice since `has_fatal_error()` internally calls it - Token kind extraction involves bit-packing operations: `((self.0 >> 64) & 0xFF) as u8` ## Solution Cache `cur_kind()` in a local variable before compound checks to eliminate redundant calls. ## Changes - **`cursor.rs:parse_delimited_list()`**: Hot loop parsing arrays, objects, parameters - reduced from 2-3 calls per iteration to 1 - **`arrow.rs:68`**: Cached kind for `LParen`/`LAngle` check - **`module.rs:101`**: Cached kind for `LCurly`/`Star` check - **`types.rs`**: Fixed 3 locations (lines 91, 558, 1188) with double `at()` calls ## Impact Every JavaScript array, object literal, function parameter list, and TypeScript type now extracts the token kind fewer times during parsing. 🤖 Generated with [Claude Code](https://claude.com/claude-code)
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Summary
Optimization to reduce redundant token kind extraction in hot paths by caching
cur_kind()results before compound checks.Problem
self.at(X) || self.at(Y)callcur_kind()twiceself.at(close) || self.has_fatal_error()callscur_kind()twice sincehas_fatal_error()internally calls it((self.0 >> 64) & 0xFF) as u8Solution
Cache
cur_kind()in a local variable before compound checks to eliminate redundant calls.Changes
cursor.rs:parse_delimited_list(): Hot loop parsing arrays, objects, parameters - reduced from 2-3 calls per iteration to 1arrow.rs:68: Cached kind forLParen/LAnglecheckmodule.rs:101: Cached kind forLCurly/Starchecktypes.rs: Fixed 3 locations (lines 91, 558, 1188) with doubleat()callsImpact
Every JavaScript array, object literal, function parameter list, and TypeScript type now extracts the token kind fewer times during parsing.
🤖 Generated with Claude Code