[phlakaton]

I'm curious to know more about the Pyre to Pyrefly transition, specifically the rewrite in Rust. Was that merely a case of trading in a lesser-known language for the language du jour? Were there specific advantages they wanted to get out of Rust?

[team_pyrefly]

Hi! We address this question in our FAQ and probably could do a longer blog post about our experience after we are further along: https://pyrefly.org/en/docs/pyrefly-faq/#why-rust

[phlakaton]

Thanks! But my real question is why the departure from OCaml. I'm guessing performance wasn't the rationale there.

[adsharma]

> Not only is Pyrefly written in a new language (Rust instead of OCaml), but its design deviates in a major way from Pyre.

I'm sure you had reasons to do it this way. But given sufficient time to market, implementing the algorithm in pyre and then tooling/llm assisted conversion to pyrefly would've been preferable.

May be you'd have had some humans in the loop initially. But that tech is getting better and aligned with the direction Meta and the rest of the industry are taking.

Yes, I'm biased :)