diff options
Diffstat (limited to 'src/stream/take.rs')
-rw-r--r-- | src/stream/take.rs | 76 |
1 files changed, 0 insertions, 76 deletions
diff --git a/src/stream/take.rs b/src/stream/take.rs deleted file mode 100644 index a92430b..0000000 --- a/src/stream/take.rs +++ /dev/null @@ -1,76 +0,0 @@ -use crate::stream::Stream; - -use core::cmp; -use core::fmt; -use core::pin::Pin; -use core::task::{Context, Poll}; -use pin_project_lite::pin_project; - -pin_project! { - /// Stream for the [`take`](super::StreamExt::take) method. - #[must_use = "streams do nothing unless polled"] - pub struct Take<St> { - #[pin] - stream: St, - remaining: usize, - } -} - -impl<St> fmt::Debug for Take<St> -where - St: fmt::Debug, -{ - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.debug_struct("Take") - .field("stream", &self.stream) - .finish() - } -} - -impl<St> Take<St> { - pub(super) fn new(stream: St, remaining: usize) -> Self { - Self { stream, remaining } - } -} - -impl<St> Stream for Take<St> -where - St: Stream, -{ - type Item = St::Item; - - fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> { - if *self.as_mut().project().remaining > 0 { - self.as_mut().project().stream.poll_next(cx).map(|ready| { - match &ready { - Some(_) => { - *self.as_mut().project().remaining -= 1; - } - None => { - *self.as_mut().project().remaining = 0; - } - } - ready - }) - } else { - Poll::Ready(None) - } - } - - fn size_hint(&self) -> (usize, Option<usize>) { - if self.remaining == 0 { - return (0, Some(0)); - } - - let (lower, upper) = self.stream.size_hint(); - - let lower = cmp::min(lower, self.remaining as usize); - - let upper = match upper { - Some(x) if x < self.remaining as usize => Some(x), - _ => Some(self.remaining as usize), - }; - - (lower, upper) - } -} |