flow VS pyre-check

It's not as popular as typescript but not dead, it's consistently active [0] for a decade.

[0] https://github.com/facebook/flow/graphs/contributors

One alternative that I found was flow, thought haven't used it. There is a bevy of languages that transpiles to JS, though some seemingly lost their attention over time. Can the bridge to WASM contribute to this or is that digressing from the topic?

I think you are mistaking Flow unmaintained for Flow actively maintained.

Hack and Flow are also written in OCaml.

So... you're referring to flow?

It seems like Facebook doesn't have problem with releasing open source project [0] while keeping centralised control over it.

[0] https://github.com/facebook/flow

Facebook uses OCaml professionally, for [Flow](https://github.com/facebook/flow), their typechecker for JavaScript, and [Pyre](https://github.com/facebook/pyre-check), their typechecker for Python.

Did you come across pyre in your search? MIT license and pretty fast.

https://github.com/facebook/pyre-check

Pyre is a performant type-checker developed by Facebook. Pyre can analyse codebases with millions of lines of code incrementally – providing instantaneous feedback to developers as they write code.

Pyre from Meta, pyright from Microsoft and PyType from Google provide additional assistance. They can 'infer' types based on code flow and existing types within the code.

Have you seen Pyre[0]? Not Rust, OCaml, and pretty fast. Made by a team at Meta and open sourced on GitHub. If you use python-lsp, I wrote an extension[1] to enable integration (though I haven't tested it recently, been programming in rust; it is mostly a "for me" extension).

0: https://pyre-check.org/

1: https://github.com/cricalix/python-lsp-pyre

Internally we use Pyre for Python type checking: https://github.com/facebook/pyre-check

Before type hinting, work had intense rules and linters enforcing docstrings with types. Now, type hints and automatic pyre runs take care of all the heavy lifting.

Python now has an optional type system and if you add one of them such as mypy or pyre to your CI process and you can configure GitHub to refuse the pull request until types are added you can make it somewhat strongly typed.

If you have a preexisting codebase I believe the way you can convert it is to add the types that you know on commits and eventually you will have enough types that adding the missing ones should be easy. For the missing ones Any is a good choice.

https://pyre-check.org and https://github.com/python/mypy are popular.