diff options
Diffstat (limited to 'third_party/rust/futures-0.1.31/src/stream/from_err.rs')
-rw-r--r-- | third_party/rust/futures-0.1.31/src/stream/from_err.rs | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/third_party/rust/futures-0.1.31/src/stream/from_err.rs b/third_party/rust/futures-0.1.31/src/stream/from_err.rs new file mode 100644 index 0000000000..4028542dfc --- /dev/null +++ b/third_party/rust/futures-0.1.31/src/stream/from_err.rs @@ -0,0 +1,80 @@ +use core::marker::PhantomData; +use poll::Poll; +use Async; +use stream::Stream; + +/// A stream combinator to change the error type of a stream. +/// +/// This is created by the `Stream::from_err` method. +#[derive(Debug)] +#[must_use = "futures do nothing unless polled"] +pub struct FromErr<S, E> { + stream: S, + f: PhantomData<E> +} + +pub fn new<S, E>(stream: S) -> FromErr<S, E> + where S: Stream +{ + FromErr { + stream: stream, + f: PhantomData + } +} + +impl<S, E> FromErr<S, E> { + /// Acquires a reference to the underlying stream that this combinator is + /// pulling from. + pub fn get_ref(&self) -> &S { + &self.stream + } + + /// Acquires a mutable reference to the underlying stream that this + /// combinator is pulling from. + /// + /// Note that care must be taken to avoid tampering with the state of the + /// stream which may otherwise confuse this combinator. + pub fn get_mut(&mut self) -> &mut S { + &mut self.stream + } + + /// Consumes this combinator, returning the underlying stream. + /// + /// Note that this may discard intermediate state of this combinator, so + /// care should be taken to avoid losing resources when this is called. + pub fn into_inner(self) -> S { + self.stream + } +} + + +impl<S: Stream, E: From<S::Error>> Stream for FromErr<S, E> { + type Item = S::Item; + type Error = E; + + fn poll(&mut self) -> Poll<Option<S::Item>, E> { + let e = match self.stream.poll() { + Ok(Async::NotReady) => return Ok(Async::NotReady), + other => other, + }; + e.map_err(From::from) + } +} + +// Forwarding impl of Sink from the underlying stream +impl<S: Stream + ::sink::Sink, E> ::sink::Sink for FromErr<S, E> { + type SinkItem = S::SinkItem; + type SinkError = S::SinkError; + + fn start_send(&mut self, item: Self::SinkItem) -> ::StartSend<Self::SinkItem, Self::SinkError> { + self.stream.start_send(item) + } + + fn poll_complete(&mut self) -> Poll<(), Self::SinkError> { + self.stream.poll_complete() + } + + fn close(&mut self) -> Poll<(), Self::SinkError> { + self.stream.close() + } +} |