blob: 4028542dfcc93ef3de837de65d97e2954894223f [file] [log] [blame]
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()
}
}