Simplify how anonymous functions are parsed

[saulshanabrook]

Updates the way that we handle passing higher order functions into egglog to remove some previous metaprogramming magic and replace it with a simpler algorithm that just removes any unbound variables left in a function and hoists them as args to the function.

[Copilot]

Pull Request Overview

This PR simplifies the handling of anonymous functions in egglog by replacing a complex metaprogramming approach with a more straightforward algorithm. The key change is removing the functionalize module and its complex introspection logic in favor of directly collecting unbound variables from function bodies and hoisting them as function arguments.

• Removes the functionalize.py module and its complex metaprogramming approach
• Adds a new collect_unbound_vars function to identify unbound variables in expressions
• Updates function conversion logic to use direct variable collection instead of code introspection

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
python/egglog/functionalize.py	Entire file removed - contained complex metaprogramming logic for function transformation
python/tests/test_functionalize.py	Entire test file removed along with the functionalize module
python/egglog/builtins.py	Replaces functionalize usage with new direct variable collection approach in _convert_function
python/egglog/declarations.py	Adds collect_unbound_vars utility function for identifying unbound variables
python/egglog/egraph.py	Simplifies _fn_decl function signature and removes unnamed function logic
python/egglog/runtime.py	Adds equality and hash methods to RuntimeFunction for comparison support
python/tests/test_high_level.py	Adds test for new UnstableFn.eval() functionality
docs/changelog.md	Documents the changes to anonymous function handling

Comments suppressed due to low confidence (1)

python/egglog/builtins.py:1100

• The variable fn shadows the function parameter fn from line 1072. Consider renaming the local variable to something like runtime_fn or fn_obj to avoid confusion.

    fn = RuntimeFunction(Thunk.value(decls), Thunk.value(fn_ref))

[codspeed-hq]

CodSpeed WallTime Performance Report

Merging #314 will improve performances by 76.22%

_{Comparing reimplemention-tmp-fn (00d1b65) with main (3b41794)¹}

Summary

⚡ 2 improvements
✅ 5 untouched benchmarks

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
⚡	test_jit[lda]	16.6 s	9.4 s	+76.22%
⚡	test_jit[tuple]	998 ms	737 ms	+35.41%

Footnotes

1. No successful run was found on main (c1d8d81) during the generation of this report, so 3b41794 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #314 will not alter performance

_{Comparing reimplemention-tmp-fn (00d1b65) with main (c1d8d81)}

Summary

✅ 7 untouched benchmarks