Red Knot Playground

[MichaReiser]

Summary

This PR adds a playground for Red Knot

Screencast.from.2024-08-14.10-33-54.webm

Sharing does work 😆 I just forgot to start wrangler.

It supports:

• Multiple files
• Showing the AST
• Showing the tokens
• Sharing
• Persistence to local storage

Future extensions:

• Configuration support: The pyproject.toml would just be another file.
• Showing type information on hover

Blockers

Salsa uses catch_unwind to break cycles, which Red Knot uses extensively when inferring types in the standard library.
However, WASM (at least wasm32-unknown-unknown) doesn't support catch_unwind today, so the playground always crashes when the type inference encounters a cycle.

I created a discussion in the salsa zulip to see if it would be possible to not use catch unwind to break cycles.

Rust tracking issue for WASM catch unwind support

I tried to build the WASM with the nightly compiler option but ran into problems because wasm-bindgen doesn't support WASM-exceptions. We could try to write the binding code by hand.

Another alternative is to use wasm32-unknown-emscripten but it's rather painful to build

[codspeed-hq]

CodSpeed Performance Report

Merging #12681 will not alter performance

_{Comparing red-knot-playground (2f7c8e3) with main (dcf31c9)}

Summary

✅ 32 untouched benchmarks

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.

Formatter (stable)

✅ ecosystem check detected no format changes.

Formatter (preview)

✅ ecosystem check detected no format changes.

[TomerBin]

Hey! Any updates about this? Do we have any sort of playground for red knot at the moment?

[MichaReiser]

No, there's no update. This is blocked on adding WASM support to salsa. See https://salsa.zulipchat.com/#narrow/stream/333573-Contributing-to-Salsa/topic/WASM.20support

[MichaReiser]

I plan to pick this up again on the side. It's now unblocked as we use salsa's new fixpoint infrastructure that doesn't rely on panics to resolve cycles.

[github-actions]

mypy_primer results

No ecosystem changes detected ✅