// begin rustme snippet: example
use futures_util::StreamExt;
use watchable::{Watchable, Watcher};

#[tokio::main]
async fn main() {
    // Create a Watchable<u32> which holds a u32 and notifies watchers when the
    // contained value changes.
    let watchable = Watchable::default();
    // Create a watcher that will efficiently be able to monitor and read the
    // contained value as it is updated.
    let watcher = watchable.watch();
    // Spawn a background worker that will print out the values the watcher reads.
    let watching_task = tokio::task::spawn(watching_task(watcher));

    // Store a sequence of values. Each time a new value is written, any waiting
    // watchers will be notified there is a new value available.
    for i in 1_u32..=1000 {
        watchable.replace(i);
    }

    // Once we're done sending values, dropping the Watchable will ensure
    // watchers are notified of the disconnection. Watchers are guaranteed to be
    // able to read the final value.
    drop(watchable);

    // Wait for the spawned task to exit.
    watching_task.await.unwrap();
}

async fn watching_task(watcher: Watcher<u32>) {
    // A Watcher can be converted into a Stream, which allows for asynchronous
    // iteration.
    let mut stream = watcher.into_stream();
    while let Some(value) = stream.next().await {
        // The value we received will not necessarily be sequential, even though
        // the main thread is publishing a complete sequence.
        println!("Read value: {value}");
    }
}
// end rustme snippet: example

#[test]
fn runs() {
    main()
}