Async Dispatcher

This crate allows async libraries to spawn tasks and set timers without being tied to a particular async runtime.

The core of this need comes from wanting to be able to use the native OS scheduler, as written about in Zed Decoded: Async Rust.

Libraries can spawn in a generic way:

use async_dispatcher::{spawn, sleep};

pub async my_library_function() {
    let task = spawn(async {
        sleep(Duration::from_secs(1)).await;
        println!("in a spawned task!");
    });

    // ...
}

Applications using those libraries can control how that work is dispatched by implementing the Dispatcher trait:

use async_dispatcher::{set_dispatcher, Dispatcher, Runnable};

struct MyAppDispatcher;

impl Dispatcher for MyAppDispatcher {
    fn dispatch(&self, runnable: Runnable) {
        // ...
    }

    fn dispatch_after(&self, duration: Duration, runnable: Runnable) {
        // ...
    }
}

fn main() {
    set_dispatcher(MyAppDispatcher);

    async_dispatcher::block_on(async move {
        my_library_function().await;
    });
}