Multi stream

Aggregate multiple streams of different types in a single stream with an item type that is a tuple of the incoming stream items.

Important

• The streams are polled and a new stream item is emitted if any if ANY of the streams emits a new value
• The values are cloned when the new stream value is emitted so incoming stream items must be clonable
• Items in the tuple being emitted are all returned in Option as their corresponding stream may never emit
• The macro supports up to 12 input streams only

Example usage

• Add to your Cargo.toml file

[dependencies]

multi_stream = "0.1.0"

• Import the muti_stream macro and pass in stream instances to create a new stream:

use async_stream::stream;
use futures::StreamExt;
use multi_stream::multi_stream;
use rand::random;
use std::time::Duration;
use tokio::time::sleep;

#[tokio::main]
async fn main() {
    let a = stream! {
        sleep(Duration::from_millis(random::<u8>().into())).await;
        yield 1;
        sleep(Duration::from_millis(random::<u8>().into())).await;
        yield 2;
        sleep(Duration::from_millis(random::<u8>().into())).await;
        yield 3;
    };
    let b = stream! {
        sleep(Duration::from_millis(random::<u8>().into())).await;
        yield 4;
        sleep(Duration::from_millis(random::<u8>().into())).await;
        yield 5;
        sleep(Duration::from_millis(random::<u8>().into())).await;
        yield 6;
    };

    multi_stream!(a, b)
        .for_each(|(a, b)| async move {
            //emitted when any of the streams has a new value
            dbg!((a, b));
        })
        .await;
}