wstd

An async Rust standard library for Wasm Components and WASI 0.2

A Bytecode Alliance project

API Docs | Releases | Contributing

This is a minimal async Rust standard library written exclusively to support Wasm Components. It exists primarily to enable people to write async-based applications in Rust before async-std, smol, or tokio land support for Wasm Components and WASI 0.2. Once those runtimes land support, it is recommended users switch to use those instead.

Examples

TCP echo server

use wstd::io;
use wstd::iter::AsyncIterator;
use wstd::net::TcpListener;
use wstd::runtime::block_on;

fn main() -> io::Result<()> {
    block_on(async move {
        let listener = TcpListener::bind("127.0.0.1:8080").await?;
        println!("Listening on {}", listener.local_addr()?);
        println!("type `nc localhost 8080` to create a TCP client");

        let mut incoming = listener.incoming();
        while let Some(stream) = incoming.next().await {
            let stream = stream?;
            println!("Accepted from: {}", stream.peer_addr()?);
            io::copy(&stream, &stream).await?;
        }
        Ok(())
    })
}

Installation

$ cargo add wstd

Safety

This crate uses #![deny(unsafe_code)], and in the very small number of exceptional cases where #[allow(unsafe_code)] is required, documentation is provided justifying its use.

Contributing

Want to join us? Check out our "Contributing" guide and take a look at some of these issues:

• Issues labeled "good first issue"
• Issues labeled "help wanted"

License

^{Licensed under Apache License, Version 2.0 with LLVM Exception.}

_{Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license with LLVM Exception, shall be licensed as above, without any additional terms or conditions.}