| use core::fmt; |
| use core::pin::Pin; |
| use futures_core::future::{Future, TryFuture}; |
| use futures_core::stream::TryStream; |
| use futures_core::task::{Context, Poll}; |
| use pin_project::{pin_project, project}; |
| |
| /// Future for the [`try_for_each`](super::TryStreamExt::try_for_each) method. |
| #[pin_project] |
| #[must_use = "futures do nothing unless you `.await` or poll them"] |
| pub struct TryForEach<St, Fut, F> { |
| #[pin] |
| stream: St, |
| f: F, |
| #[pin] |
| future: Option<Fut>, |
| } |
| |
| impl<St, Fut, F> fmt::Debug for TryForEach<St, Fut, F> |
| where |
| St: fmt::Debug, |
| Fut: fmt::Debug, |
| { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| f.debug_struct("TryForEach") |
| .field("stream", &self.stream) |
| .field("future", &self.future) |
| .finish() |
| } |
| } |
| |
| impl<St, Fut, F> TryForEach<St, Fut, F> |
| where St: TryStream, |
| F: FnMut(St::Ok) -> Fut, |
| Fut: TryFuture<Ok = (), Error = St::Error>, |
| { |
| pub(super) fn new(stream: St, f: F) -> TryForEach<St, Fut, F> { |
| TryForEach { |
| stream, |
| f, |
| future: None, |
| } |
| } |
| } |
| |
| impl<St, Fut, F> Future for TryForEach<St, Fut, F> |
| where St: TryStream, |
| F: FnMut(St::Ok) -> Fut, |
| Fut: TryFuture<Ok = (), Error = St::Error>, |
| { |
| type Output = Result<(), St::Error>; |
| |
| #[project] |
| fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> { |
| #[project] |
| let TryForEach { mut stream, f, mut future } = self.project(); |
| loop { |
| if let Some(fut) = future.as_mut().as_pin_mut() { |
| ready!(fut.try_poll(cx))?; |
| future.set(None); |
| } else { |
| match ready!(stream.as_mut().try_poll_next(cx)?) { |
| Some(e) => future.set(Some(f(e))), |
| None => break, |
| } |
| } |
| } |
| Poll::Ready(Ok(())) |
| } |
| } |