First off, any help is welcome 🙂 I reached a point in my dabbling where I felt I got pretty deep into inferring types for pretty much everything and anything, so fear it’ll risk of becoming a performance bottleneck. Right now I’m contemplating a move of what I have to rust using

python-rust

crate for parsing to AST, while still leveraging the type information we have from a running Python interpreter and have that in a dedicated crate in a non-pants specific form which can then be consumed by our rule visitor.

(same crate ruff uses for it’s python parser)

i think that getting a single narrow

UnionMembership

lookup syntax working (even if it is awkward) could be really helpful, since the syntax being awkward or limited overwhelmingly affects Pants maintainers (who define/consume `@union`s), rather than end users (who only implement `@union`s)

so if

impls = union_membership.get(UnionType)

works, for example, that’s enough

but i recognize that even that might be a lot of work.

i like the idea of porting the extraction to rust though.

and, wow: i didn’t realize that

ruff

used `rustpython`’s parser… that’s wild. i wonder how they feel about that, heh.

…apparently they’re very aware, and have gotten some contributions because of it. cool!

with the longer term goal to have most of the heavylifting in rust