Hacker News Reader

Comment by dsizzle | Hacker News Reader

Copy-pasting the if/else code (step 2) and then executing resulted in it spinning for about 20 seconds before I lost interest and killed it. The "Hello World" (step 1) did complete, after about 6 seconds.

View on HN

Works for me, looks like your internet might be slow, at least when connecting to this site, as I believe it works by running the code in the cloud and streaming the results to you. Or perhaps it works on the machine, not sure.

Since Rust can compile to JS and WebAssembly, and Rust's compiler is written in Rust... could you compile Rust in a browser?

The hardest part would probably be getting LLVM (written in C++) to compile to webassembly, since that's what rust uses as a compiler backend.

It takes some work (mostly due to LLVM building code to run later in its build system as it goes), but it's very feasible. LLVM has been ported to Wasm (and before that to JS) many times, for example:

https://github.com/jprendes/emception (2021)

https://github.com/tbfleming/cib (2017)

https://github.com/kripken/llvm.js (2012)

I agree it would be great to see this repl running 100% in the browser!

Turns out there's been some work, and the rust part has actually been the main issue: https://github.com/rust-lang/miri/issues/722

I have been waiting for this to emerge for a few years, but I assume that it must be very difficult because it hasn't happened yet.

It's probably difficult and also seems mostly useless, right?

It's inconsistent for me - sometimes it runs fine and runs almost immediately, sometimes it hangs for a long time.

Reply on news.ycombinator.com