You may be right. I think Flow was a predecessor to TypeScript.

I just checked out Flow and woah. First-class syntax sugar for React. Maybe cool. (If it doesn't break catastrophically in a sane build system like Vite)

Are you sure? The React compiler is a fairly new addition to React, Flow is Facebook's old alternative to Typescript, but Typescript won the ecosystem in terms of broad adoption in the end. I think Flow is barely used today, I would be really surprised if they choose it for a new tool, even for a Facebook project.

You may be thinking about React itself, not the new compiler? I'm sure there must be some flow in there still from back in the day.

The benefit of Rust over TypeScript is that Rust is faster.

TypeScript is memory-safe, but you can't really control where the memory comes from. In Rust you have structs, traits, references and all sorts of things to control both your memory usage and your memory efficiency, and you just don't really get that in TypeScript. Plus, in Rust it's a lot easier to utilize multithreading -- JS is notoriously tedious to parallelize (message-passing between JS workers is a bit annoying compared to structured concurrency in Rust)

I think the benefit of rust here is that it's not hosted whereas typescript is