ps_promise/methods/
race.rs

1use std::{future::Future, pin::pin, task::Poll};
2
3use crate::{Promise, PromiseRejection};
4
5impl<T, E> Promise<T, E>
6where
7    T: Send + Unpin + 'static,
8    E: PromiseRejection,
9{
10    pub fn race<I>(promises: I) -> Self
11    where
12        I: IntoIterator<Item = Self>,
13    {
14        Self::new(PromiseRace::from(promises))
15    }
16}
17
18impl<T, E> Future for PromiseRace<T, E>
19where
20    T: Send + Unpin + 'static,
21    E: PromiseRejection,
22{
23    type Output = Result<T, E>;
24
25    fn poll(
26        self: std::pin::Pin<&mut Self>,
27        cx: &mut std::task::Context<'_>,
28    ) -> std::task::Poll<Self::Output> {
29        let this = self.get_mut();
30
31        for promise in &mut this.promises {
32            if let Poll::Ready(result) = pin!(promise).poll(cx) {
33                return Poll::Ready(result);
34            }
35        }
36
37        Poll::Pending
38    }
39}
40
41pub struct PromiseRace<T, E>
42where
43    T: Send + Unpin + 'static,
44    E: PromiseRejection,
45{
46    promises: Vec<Promise<T, E>>,
47}
48
49impl<I, T, E> From<I> for PromiseRace<T, E>
50where
51    T: Send + Unpin + 'static,
52    E: PromiseRejection,
53    I: IntoIterator<Item = Promise<T, E>>,
54{
55    fn from(value: I) -> Self {
56        Self {
57            promises: value.into_iter().collect(),
58        }
59    }
60}
ps_promise/methods/race.rs

ps_promise/methods/
race.rs
