WASM support

[arendjr]

Do you think it might be possible to support WebAssembly as a target for papaya? Currently, it appears broken due to missing support in the atomic-wait dependency.

[ibraheemdev]

Hmm yes I think we can get rid of the atomic-wait dependency as we have an internal parker. Is that the only blocker?

[arendjr]

I think it is, but I haven't dug too deep. I see seize is also written by you, and its only dependency (libc) is already optional, so that'll probably just work. Serde certainly shouldn't be a problem. I have only briefly checked if you use std features that may be problematic on WASM. Most of it just works, but there are a few edge cases. Spawning threads is generally off the table, but I think your use of threads::current() is probably fine. After all, the docs say:

The thread::current function is available even for threads not spawned by the APIs of this module.

Locks and atomics should just work AFAIK, and will just assume you're in a single-threaded context anyway (at least for the wasm32-unknown-unknown target).

For Biome I wrote a papaya shim last night: biomejs/biome@3e350f9
But if we can get rid of it, I would be most happy. I'm not that comfortable with writing unsafe myself, and I think there may be an unsoundness in my shim when you take a reference to a value in the map and then mutate the map while hanging onto the reference. That's probably not a big deal for our use case, but I'd rather avoid it if we can.

[ibraheemdev]

Let me know if there's anything else I can do to help with this, I will cut a release soon.

[arendjr]

Thanks a lot!

[arendjr]

Just confirmed with your latest Git version, it compiles and appears to work fine 👍