perf(isolated_declarations): use `ReplaceWith` instead of `TakeIn` by overlookmotel · Pull Request #24016 · oxc-project/oxc

overlookmotel · 2026-07-01T15:53:20Z

Replace take_in with replace_with in as many places as possible in isolated declarations. See #24012 for explanation of the advantage of replace_with.

overlookmotel · 2026-07-01T15:53:40Z

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codspeed-hq · 2026-07-01T15:57:18Z

Merging this PR will not alter performance

✅ 52 untouched benchmarks
⏩ 19 skipped benchmarks¹

_{Comparing om/07-01-perf_isolated_declarations_use_replacewith_instead_of_takein_ (e1ad60b) with om/07-01-perf_transformer_use_replacewith_instead_of_takein_ (9d36ab6)²}

19 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. ↩
No successful run was found on om/07-01-perf_transformer_use_replacewith_instead_of_takein_ (0f9d621) during the generation of this report, so 17cdb6c was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

Copilot

Pull request overview

Updates oxc_isolated_declarations to prefer ReplaceWith over TakeIn when mutating AST nodes in-place, reducing unnecessary arena allocations from dummy “take” values.

Changes:

Replace take_in usage with replace_with in strip_export_keyword and binding-pattern mutation.
Refactor strip_export_keyword into an associated function and update call sites.
Simplify FormalParameterBindingPattern by removing the stored allocator and using ReplaceWith.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
crates/oxc_isolated_declarations/src/module.rs	Switch `strip_export_keyword` to `replace_with` and make it an associated function.
crates/oxc_isolated_declarations/src/lib.rs	Update callers to use `Self::strip_export_keyword`.
crates/oxc_isolated_declarations/src/function.rs	Update calls to the new `remove_assignments_from_kind` signature.
crates/oxc_isolated_declarations/src/formal_parameter_binding_pattern.rs	Replace `take_in` pattern extraction with `replace_with`, and refactor visitor construction (currently has a compile error).

Dunqing · 2026-07-05T14:43:17Z

Merge activity

Jul 5, 2:43 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Jul 5, 2:43 PM UTC: Dunqing added this pull request to the Graphite merge queue.
Jul 5, 2:50 PM UTC: Merged by the Graphite merge queue.

…24016) Replace `take_in` with `replace_with` in as many places as possible in isolated declarations. See #24012 for explanation of the advantage of `replace_with`.

### 🚀 Features - 260425f semantic/examples: Include unresolved references (#24214) (camc314) - 2d9b0b3 minifier: Fold boolean-literal ternary branches in value contexts (#24110) (Dunqing) - 61fbf10 ast: Implement `ReplaceWith` on all AST types (#24013) (overlookmotel) - 7db7a29 allocator: Add `ReplaceWith` trait (#24012) (overlookmotel) - 4eb074e mangler: Add `reserved` option for names that must not be mangled (#24041) (Dunqing) - 2e62012 data_structures: Add `StringExt` trait (#24006) (overlookmotel) - 60e7160 minifier: Drop side-effect-free IIFEs whose result is unused (#23967) (Dunqing) - 26dd9e2 ast: Add method to widen inherited enum ref to parent ref (#23961) (overlookmotel) ### 🐛 Bug Fixes - e8b50ee transformer: Clean up semantics for stripped TypeScript syntax (#24180) (camc314) - d966d0b react_compiler: Remove clippy allows (#24168) (Boshen) - 854ef8d react_compiler: Compile generic functions instead of over-bailing on type-param hoisting (#24158) (Boshen) - 093586c react_compiler: Align memoization cache-slot allocation with Babel (#24157) (Boshen) - 09c8f59 react_compiler: Normalize snapshot fixture paths (#24142) (camc314) - f13df97 react_compiler: Drop stray empty statement from catch bindings (#24133) (Boshen) - cb2a505 react_compiler: Codegen destructuring reassignment targets (#24131) (Boshen) - b82c394 react_compiler: Propagate codegen invariants instead of emitting empty bodies (#24128) (Boshen) - 5771982 react_compiler: Render unchanged programs as source in fixture snapshots (#24129) (Boshen) - 4b16e1a transformer/async-to-generator: Preserve direct eval scope flags (#24136) (camc314) - 4e9194f react_compiler: Lower `delete obj.prop` to Property/ComputedDelete (#24123) (Boshen) - 0b25582 ast: Type binding node `typeAnnotation` as `TSTypeAnnotation | null` (#23113) (Boshen) - 018c0e5 transformer: Hoist lowered async declarations (#22770) (camc314) - 652fbaf mangler: Keep names of destructured exported bindings (#24036) (Dunqing) - e274415 minifier: Don't drop global calls that throw despite pure arguments (#23917) (Dunqing) - 59abb30 minifier: Only merge string literals in `try_fold_add` when the inner operator is `+` (#23622) (Jerry Zhao) ### ⚡ Performance - c5ca77b transformer: Avoid cloning refresh options (#24191) (camc314) - bf1a151 react_compiler: Compile out debug printers (#24184) (Boshen) - abb44a0 transformer: Build fixed object-rest arguments (#24190) (camc314) - a4db731 isolated_declarations: Use `ReplaceWith` instead of `TakeIn` (#24016) (overlookmotel) - ff10855 transformer: Use `ReplaceWith` instead of `TakeIn` (#24015) (overlookmotel) - bd49aff ecmascript: Avoid heap-allocating Math.min/max/imul operands (#23941) (Lawrence Lin) - e4b708b react_compiler: Skip compiled files before prefilters (#24171) (Boshen) - c59f2fe rust: Return impl ExactSizeIterator from slice-backed accessors (#24144) (Boshen) - 5d6d04a codegen: SWAR-skip boring byte runs in sourcemap line/column scan (#24023) (Boshen) - a55e0be traverse: Reduce string operations in `get_var_name_from_node` (#24007) (overlookmotel) - e6d48e1 transformer/nullish_coalescing: Move cold path into separate function (#23989) (overlookmotel) - c4e35b5 transformer/object_rest_spread: Pre-allocate capacity in `Vec` (#23988) (overlookmotel) - 527b8e5 transformer/decorators: Narrow type earlier (#23987) (overlookmotel) ### 📚 Documentation - 30d17f5 allocator: Clarify docs for `TakeIn::take_in_box` (#24093) (overlookmotel) - 675e6a8 ast: Correct doc comment for `PrivateFieldExpression` (#24008) (overlookmotel) - e4c30e6 minifier: Explain what `dce` mode means (#23994) (Dunqing) - 37cbf88 ast_macros: Document fields of `StructDetails` (#23959) (overlookmotel) - 4de3e54 ast: Correct doc comment (#23948) (overlookmotel) Co-authored-by: Boshen <[email protected]>

overlookmotel mentioned this pull request Jul 1, 2026

perf(transformer): use ReplaceWith instead of TakeIn #24015

Merged

github-actions Bot added the A-isolated-declarations Isolated Declarations label Jul 1, 2026

This was referenced Jul 1, 2026

perf(minifier): use ReplaceWith instead of TakeIn #24017

Merged

perf(parser): use ReplaceWith instead of TakeIn #24018

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overlookmotel assigned Dunqing Jul 1, 2026

overlookmotel marked this pull request as ready for review July 1, 2026 16:37

overlookmotel requested a review from Dunqing as a code owner July 1, 2026 16:38

Copilot AI review requested due to automatic review settings July 1, 2026 16:38

Copilot started reviewing on behalf of overlookmotel July 1, 2026 16:38 View session

Copilot AI reviewed Jul 1, 2026

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Comment thread crates/oxc_isolated_declarations/src/formal_parameter_binding_pattern.rs Outdated

overlookmotel force-pushed the om/07-01-perf_transformer_use_replacewith_instead_of_takein_ branch from d61e3e8 to 547d76d Compare July 1, 2026 18:01

overlookmotel force-pushed the om/07-01-perf_isolated_declarations_use_replacewith_instead_of_takein_ branch from 1d5370a to 0b6374a Compare July 1, 2026 18:01

graphite-app Bot force-pushed the om/07-01-perf_transformer_use_replacewith_instead_of_takein_ branch from 547d76d to 9d36ab6 Compare July 2, 2026 01:40

graphite-app Bot force-pushed the om/07-01-perf_isolated_declarations_use_replacewith_instead_of_takein_ branch from 0b6374a to 6c6b14d Compare July 2, 2026 01:40

overlookmotel force-pushed the om/07-01-perf_isolated_declarations_use_replacewith_instead_of_takein_ branch from 6c6b14d to e1ad60b Compare July 2, 2026 21:50

overlookmotel force-pushed the om/07-01-perf_transformer_use_replacewith_instead_of_takein_ branch from 9d36ab6 to 0f9d621 Compare July 2, 2026 21:50

Dunqing approved these changes Jul 5, 2026

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Dunqing added the 0-merge Merge with Graphite Merge Queue label Jul 5, 2026

perf(isolated_declarations): use ReplaceWith instead of TakeIn (#…

a4db731

…24016) Replace `take_in` with `replace_with` in as many places as possible in isolated declarations. See #24012 for explanation of the advantage of `replace_with`.

graphite-app Bot force-pushed the om/07-01-perf_transformer_use_replacewith_instead_of_takein_ branch from 0f9d621 to ff10855 Compare July 5, 2026 14:45

graphite-app Bot requested a review from camc314 as a code owner July 5, 2026 14:45

graphite-app Bot force-pushed the om/07-01-perf_isolated_declarations_use_replacewith_instead_of_takein_ branch from e1ad60b to a4db731 Compare July 5, 2026 14:45

graphite-app Bot removed the 0-merge Merge with Graphite Merge Queue label Jul 5, 2026

Base automatically changed from om/07-01-perf_transformer_use_replacewith_instead_of_takein_ to main July 5, 2026 14:50

graphite-app Bot merged commit a4db731 into main Jul 5, 2026
31 checks passed

graphite-app Bot deleted the om/07-01-perf_isolated_declarations_use_replacewith_instead_of_takein_ branch July 5, 2026 14:50

oxc-guard Bot mentioned this pull request Jul 6, 2026

release(crates): oxc v0.139.0 #24218

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perf(isolated_declarations): use `ReplaceWith` instead of `TakeIn`#24016

perf(isolated_declarations): use `ReplaceWith` instead of `TakeIn`#24016
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Merging this PR will not alter performance

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