refactor(ast, regular_expression): shorten ContentEq implementations

[overlookmotel]

Shorten codegen-ed implementations of ContentEq for enums, matching what Rust produces for #[derive(PartialEq)] (inspired by #8517).

[overlookmotel]

• refactor(ast, regular_expression): shorten ContentEq implementations #8519 👈 (View in Graphite)
• main

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[codspeed-hq]

CodSpeed Performance Report

Merging #8519 will not alter performance

_{Comparing 01-15-refactor_ast_regular_expression_shorten_contenteq_implementations (30f8ec3) with main (04bc259)}

Summary

✅ 32 untouched benchmarks

[overlookmotel]

@camc314 I half-hoped this would produce a speed-up too, but no. I think ContentEq is just inherently expensive, especially when the 2 AST fragments being compared are large and mostly the same, so you have to crawl a long way through the structures to find out if they're the same or not.

But at least the code is more compact and readable using the style you suggested.

[camc314]

thanks for looking at this.

yeah i agree. bit ast node == lots of time. can probably speed up performance by doing that minification in a later pass and running it less times.

it might be worth double checking this. but i think this approach has worse performance than before. If we consider "left" and "other", if "left" matches the first enum variant on the first thing of the match statement, and right does not, it will try ever match pattern rather than bailing out early. << this might not be correct, but it's what i understood from godbolt and some rust forums