Add pyright type-checking

[MartinBernstorff]

Description

Love the inline type-checking in VSCode, and would love to see it here as well.

Suggested solution

Add pyright type-checking and underlining.

Alternative

No response

Additional context

No response

[akshayka]

Thanks for the suggestion. We'd like to add a language server at some point, and this would be a great feature.

[aszenz]

I don't even see syntax error checking in the editor, this makes it difficult to work in.
So basic diagnostics and linting would be welcome.

[mscolnick]

@aszenz, this is coming in #3414

[MartinBernstorff]

@mscolnick Apologies, wanted to unsubscribe, not close :-)

[mscolnick]

for the folks interested in pyright. we do have type-checking via mypy and python-language-server:

pip install "marimo[lsp]" pylsp-mypy

And enable Diagnostics in the settings modal

I am curious if this works for folks, or if they are specifically looking for pyright (and not mypy)

[ilyagr]

There are now two brand new typecheckers that claim to be quite fast, both written in Rust:

Pyrefly, https://pyrefly.org/ (already has IDE support)

ty, https://github.com/astral-sh/ty (can act as an LSP server, shares some code with ruff, says it is not "production ready" yet).

I imagine both try to improve on top of pyright. If you scroll down a bit on Pyrefly's website I linked, it claims to be more than 10x faster than pyright or mypy.

[winstxnhdw]

I am interested in replacing Pyright with ty in marimo. Will experiment on some POCs and maybe a draft PR, then we can later evaluate if we would like to be an early adopter.

As of now, ty is more performant than Pyrefly in the latest benchmarks and I am betting that ty will remain the winner in this race, in terms of strictness and performance.

[ilyagr]

There's an interesting comparison of pyrefly and ty: https://blog.edward-li.com/tech/comparing-pyrefly-vs-ty/, https://lobste.rs/s/2uukup/pyrefly_vs_ty_comparing_python_s_two_new.

TLDR: they have quite different philosophies in terms of whether to prioritize correctness or ease of use to gradually add types to an existing codebase.

Another funny tidbit is that both use ruff to parse python.

So, it might take some thought to decide which works better for marimo, and it might make sense to support both.

[dmadisetti]

Last I tried Ty, it was definitely not production ready (but was super fast). Their playground is also super fun: https://play.ty.dev/ and in browser LSP would be cool

Another funny tidbit is that both use ruff to parse python.

This is surprising because the astral semantics api definitely doesn't look like a public API- but I guess meta could have always forked