refactor(lexer): simplify byte handler macros

[overlookmotel]

Pure refactor. Simplify the byte handler macros in lexer in 3 ways:

1. Remove the const BLAH: ByteHandler = { ... }; wrappers from generated code

I don't think they're necessary, and I'm not sure why I put them there in the first place.

Before:

const UNI: ByteHandler = {
    #[expect(non_snake_case)]
    fn UNI(lexer: &mut Lexer) -> Kind {
        lexer.unicode_char_handler()
    }
    UNI
};

After:

#[expect(non_snake_case)]
fn UNI(lexer: &mut Lexer) -> Kind {
    lexer.unicode_char_handler()
}

Each byte handler still has a useful name in CodSpeed flame graphs after this change.

2. Remove the byte_handler! macro.

ascii_byte_handler! and ascii_identifier_handler! macros remain, but they no longer use byte_handler! macro internally.

Removing the macro-within-macro pattern may make this code easier for AI to understand (and probably ditto for humans!).

3. Shorten macro expansion

Hoist use oxc_data_structures::assert_unchecked; to top of file, so it doesn't need to be repeated in each macro expansion.

[overlookmotel]

• refactor(lexer): simplify byte handler macros #13057 👈 (View in Graphite)
• main

---

How to use the Graphite Merge Queue

Add either label to this PR to merge it via the merge queue:

• 0-merge - adds this PR to the back of the merge queue
• hotfix - for urgent hot fixes, skip the queue and merge this PR next

You must have a Graphite account in order to use the merge queue. Sign up using this link.

An organization admin has enabled the Graphite Merge Queue in this repository.

Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue.

This stack of pull requests is managed by Graphite. Learn more about stacking.

[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #13057 will improve performances by 3.09%

_{Comparing 08-12-refactor_lexer_simplify_byte_handler_macros (fdfec21) with main (b0558a4)¹}

Summary

⚡ 1 improvements
✅ 33 untouched benchmarks

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
⚡	minifier[cal.com.tsx]	34.1 ms	33.1 ms	+3.09%

Footnotes

1. No successful run was found on main (fdfec21) during the generation of this report, so b0558a4 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[Copilot]

Pull Request Overview

This PR refactors the byte handler macros in the lexer to simplify the generated code structure and improve readability. The changes eliminate unnecessary const wrappers, remove the intermediate byte_handler! macro, and reduce code duplication by hoisting common imports.

• Remove const wrappers from generated byte handler functions
• Eliminate the byte_handler! macro and inline its functionality into the remaining macros
• Hoist use oxc_data_structures::assert_unchecked; to the top of the file to avoid repetition

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[Boshen]

Merge activity

• Aug 13, 3:32 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Aug 13, 3:33 PM UTC: Boshen added this pull request to the Graphite merge queue.
• Aug 13, 3:38 PM UTC: Merged by the Graphite merge queue.