use core::future::Future;
use core::pin::Pin;
use crate::stream::Stream;
use crate::task::{Context, Poll};
#[doc(hidden)]
#[allow(missing_debug_implementations)]
pub struct TryForEachFuture<'a, S, F> {
stream: &'a mut S,
f: F,
}
impl<'a, S, F> Unpin for TryForEachFuture<'a, S, F> {}
impl<'a, S, F> TryForEachFuture<'a, S, F> {
pub(crate) fn new(stream: &'a mut S, f: F) -> Self {
Self { stream, f }
}
}
impl<'a, S, F, E> Future for TryForEachFuture<'a, S, F>
where
S: Stream + Unpin,
F: FnMut(S::Item) -> Result<(), E>,
{
type Output = Result<(), E>;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
loop {
let item = futures_core::ready!(Pin::new(&mut self.stream).poll_next(cx));
match item {
None => return Poll::Ready(Ok(())),
Some(v) => {
let res = (&mut self.f)(v);
if let Err(e) = res {
return Poll::Ready(Err(e));
}
}
}
}
}
}