[−][src]Struct futures::stream::Map

#[must_use = "streams do nothing unless polled"]

pub struct Map<St, F> { /* fields omitted */ }

A stream combinator which will change the type of a stream from one type to another.

This is produced by the Stream::map method.

Methods

impl<St, T, F> Map<St, F> where
    F: FnMut(<St as Stream>::Item) -> T,
    St: Stream, [src]

pub fn get_ref(&self) -> &St[src]

Acquires a reference to the underlying stream that this combinator is pulling from.

pub fn get_mut(&mut self) -> &mut St[src]

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 into_inner(self) -> St[src]

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.

Trait Implementations

impl<St, F> Unpin for Map<St, F> where
    St: Unpin, [src]

impl<St, F> Debug for Map<St, F> where
    F: Debug,
    St: Debug, [src]

impl<St, F, T> Stream for Map<St, F> where
    F: FnMut(<St as Stream>::Item) -> T,
    St: Stream, [src]

type Item = T

Values yielded by the stream.

impl<St, F> FusedStream for Map<St, F> where
    St: FusedStream, [src]

Auto Trait Implementations

impl<St, F> Send for Map<St, F> where
    F: Send,
    St: Send, 

impl<St, F> Sync for Map<St, F> where
    F: Sync,
    St: Sync, 

Blanket Implementations

impl<T, U> Into for T where
    U: From<T>, [src]

impl<T> From for T[src]

impl<T, U> TryFrom for T where
    U: Into<T>, [src]

type Error = !

🔬 This is a nightly-only experimental API. (try_from)

The type returned in the event of a conversion error.

impl<T> Borrow for T where
    T: ?Sized, [src]

impl<T> Any for T where
    T: 'static + ?Sized, [src]

impl<T> BorrowMut for T where
    T: ?Sized, [src]

impl<T, U> TryInto for T where
    U: TryFrom<T>, [src]

type Error = <U as TryFrom<T>>::Error

🔬 This is a nightly-only experimental API. (try_from)

The type returned in the event of a conversion error.

impl<T> StreamExt for T where
    T: Stream + ?Sized, [src]

fn next(&mut self) -> Next<Self> where
    Self: Unpin, [src]

Creates a future that resolves to the next item in the stream. Read more

fn into_future(self) -> StreamFuture<Self> where
    Self: Unpin, [src]

Converts this stream into a future of (next_item, tail_of_stream). If the stream terminates, then the next item is [None]. Read more

fn map<T, F>(self, f: F) -> Map<Self, F> where
    F: FnMut(Self::Item) -> T, [src]

Maps this stream's items to a different type, returning a new stream of the resulting type. Read more

fn filter<Fut, F>(self, f: F) -> Filter<Self, Fut, F> where
    F: FnMut(&Self::Item) -> Fut,
    Fut: Future<Output = bool>, [src]

Filters the values produced by this stream according to the provided asynchronous predicate. Read more

fn filter_map<Fut, T, F>(self, f: F) -> FilterMap<Self, Fut, F> where
    F: FnMut(Self::Item) -> Fut,
    Fut: Future<Output = Option<T>>, [src]

Filters the values produced by this stream while simultaneously mapping them to a different type according to the provided asynchronous closure. Read more

fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F> where
    F: FnMut(Self::Item) -> Fut,
    Fut: Future, [src]

Computes from this stream's items new items of a different type using an asynchronous closure. Read more

fn collect<C>(self) -> Collect<Self, C> where
    C: Default + Extend<Self::Item>, [src]

Collect all of the values of this stream into a vector, returning a future representing the result of that computation. Read more

fn concat(self) -> Concat<Self> where
    Self::Item: Extend<<Self::Item as IntoIterator>::Item>,
    Self::Item: IntoIterator,
    Self::Item: Default, [src]

Concatenate all items of a stream into a single extendable destination, returning a future representing the end result. Read more

fn fold<T, Fut, F>(self, init: T, f: F) -> Fold<Self, Fut, T, F> where
    F: FnMut(T, Self::Item) -> Fut,
    Fut: Future<Output = T>, [src]

Execute an accumulating asynchronous computation over a stream, collecting all the values into one final result. Read more

fn flatten(self) -> Flatten<Self> where
    Self::Item: Stream, [src]

Flattens a stream of streams into just one continuous stream. Read more

fn skip_while<Fut, F>(self, f: F) -> SkipWhile<Self, Fut, F> where
    F: FnMut(&Self::Item) -> Fut,
    Fut: Future<Output = bool>, [src]

Skip elements on this stream while the provided asynchronous predicate resolves to true. Read more

fn take_while<Fut, F>(self, f: F) -> TakeWhile<Self, Fut, F> where
    F: FnMut(&Self::Item) -> Fut,
    Fut: Future<Output = bool>, [src]

Take elements from this stream while the provided asynchronous predicate resolves to true. Read more

fn for_each<Fut, F>(self, f: F) -> ForEach<Self, Fut, F> where
    F: FnMut(Self::Item) -> Fut,
    Fut: Future<Output = ()>, [src]

Runs this stream to completion, executing the provided asynchronous closure for each element on the stream. Read more

fn for_each_concurrent<Fut, F, impl Into>>(
    self,
    limit: impl Into>,
    f: F
) -> ForEachConcurrent<Self, Fut, F> where
    F: FnMut(Self::Item) -> Fut,
    Fut: Future<Output = ()>,
    impl Into>: Into<Option<usize>>, [src]

Runs this stream to completion, executing the provided asynchronous closure for each element on the stream concurrently as elements become available. Read more

fn take(self, n: u64) -> Take<Self>[src]

Creates a new stream of at most n items of the underlying stream. Read more

fn skip(self, n: u64) -> Skip<Self>[src]

Creates a new stream which skips n items of the underlying stream. Read more

fn fuse(self) -> Fuse<Self>[src]

Fuse a stream such that poll_next will never again be called once it has finished. This method can be used t turn any Stream into a FusedStream. Read more

fn by_ref(&mut self) -> &mut Self[src]

Borrows a stream, rather than consuming it. Read more

fn catch_unwind(self) -> CatchUnwind<Self> where
    Self: UnwindSafe, [src]

Catches unwinding panics while polling the stream. Read more

fn boxed(self) -> Pin<Box<Self>>[src]

Wrap the stream in a Box, pinning it.

fn buffered(self, n: usize) -> Buffered<Self> where
    Self::Item: Future, [src]

An adaptor for creating a buffered list of pending futures. Read more

fn buffer_unordered(self, n: usize) -> BufferUnordered<Self> where
    Self::Item: Future, [src]

An adaptor for creating a buffered list of pending futures (unordered). Read more

fn zip<St>(self, other: St) -> Zip<Self, St> where
    St: Stream, [src]

An adapter for zipping two streams together. Read more

fn chain<St>(self, other: St) -> Chain<Self, St> where
    St: Stream<Item = Self::Item>, [src]

Adapter for chaining two stream. Read more

fn peekable(self) -> Peekable<Self>[src]

Creates a new stream which exposes a peek method. Read more

fn chunks(self, capacity: usize) -> Chunks<Self>[src]

An adaptor for chunking up items of the stream inside a vector. Read more

fn select<St>(self, other: St) -> Select<Self, St> where
    St: Stream<Item = Self::Item>, [src]

This combinator will attempt to pull items from both streams. Each stream will be polled in a round-robin fashion, and whenever a stream is ready to yield an item that item is yielded. Read more

fn forward<S>(self, sink: S) -> Forward<Self, S> where
    S: Sink + Unpin,
    Self: Stream<Item = Result<<S as Sink>::SinkItem, <S as Sink>::SinkError>>, [src]

A future that completes after the given stream has been fully processed into the sink, including flushing. Read more

fn split(self) -> (SplitSink<Self>, SplitStream<Self>) where
    Self: Sink, [src]

Splits this Stream + Sink object into separate Stream and Sink objects. Read more

fn inspect<F>(self, f: F) -> Inspect<Self, F> where
    F: FnMut(&Self::Item), [src]

Do something with each item of this stream, afterwards passing it on. Read more

fn left_stream<B>(self) -> Either<Self, B> where
    B: Stream<Item = Self::Item>, [src]

Wrap this stream in an Either stream, making it the left-hand variant of that Either. Read more

fn right_stream<B>(self) -> Either<B, Self> where
    B: Stream<Item = Self::Item>, [src]

Wrap this stream in an Either stream, making it the right-hand variant of that Either. Read more

fn poll_next_unpin(&mut self, waker: &Waker) -> Poll<Option<Self::Item>> where
    Self: Unpin, [src]

A convenience method for calling [Stream::poll_next] on [Unpin] stream types. Read more

fn select_next_some(&mut self) -> SelectNextSome<Self> where
    Self: Unpin + FusedStream, [src]

Returns a [Future] that resolves when the next item in this stream is ready. Read more

impl<S, T, E> TryStream for S where
    S: Stream<Item = Result<T, E>>, [src]

type Ok = T

The type of successful values yielded by this future

type Error = E

The type of failures yielded by this future

impl<S> TryStreamExt for S where
    S: TryStream, [src]

fn err_into<E>(self) -> ErrInto<Self, E> where
    Self::Error: Into<E>, [src]

Wraps the current stream in a new stream which converts the error type into the one provided. Read more

fn map_ok<T, F>(self, f: F) -> MapOk<Self, F> where
    F: FnMut(Self::Ok) -> T, [src]

Wraps the current stream in a new stream which maps the success value using the provided closure. Read more

fn map_err<E, F>(self, f: F) -> MapErr<Self, F> where
    F: FnMut(Self::Error) -> E, [src]

Wraps the current stream in a new stream which maps the error value using the provided closure. Read more

fn into_stream(self) -> IntoStream<Self>[src]

Wraps a [TryStream] into a type that implements Stream Read more

fn try_next(&mut self) -> TryNext<Self> where
    Self: Unpin, [src]

Creates a future that attempts to resolve the next item in the stream. If an error is encountered before the next item, the error is returned instead. Read more

fn try_for_each<Fut, F>(self, f: F) -> TryForEach<Self, Fut, F> where
    F: FnMut(Self::Ok) -> Fut,
    Fut: TryFuture<Ok = (), Error = Self::Error>, [src]

Attempts to run this stream to completion, executing the provided asynchronous closure for each element on the stream. Read more

fn try_skip_while<Fut, F>(self, f: F) -> TrySkipWhile<Self, Fut, F> where
    F: FnMut(&Self::Ok) -> Fut,
    Fut: TryFuture<Ok = bool, Error = Self::Error>, [src]

Skip elements on this stream while the provided asynchronous predicate resolves to true. Read more

fn try_for_each_concurrent<Fut, F, impl Into>>(
    self,
    limit: impl Into>,
    f: F
) -> TryForEachConcurrent<Self, Fut, F> where
    F: FnMut(Self::Ok) -> Fut,
    Fut: Future<Output = Result<(), Self::Error>>,
    impl Into>: Into<Option<usize>>, [src]

Attempts to run this stream to completion, executing the provided asynchronous closure for each element on the stream concurrently as elements become available, exiting as soon as an error occurs. Read more

fn try_collect<C>(self) -> TryCollect<Self, C> where
    C: Default + Extend<Self::Ok>, [src]

Attempt to Collect all of the values of this stream into a vector, returning a future representing the result of that computation. Read more

fn try_filter_map<Fut, F, T>(self, f: F) -> TryFilterMap<Self, Fut, F> where
    F: FnMut(Self::Ok) -> Fut,
    Fut: TryFuture<Ok = Option<T>, Error = Self::Error>, [src]

Attempt to filter the values produced by this stream while simultaneously mapping them to a different type according to the provided asynchronous closure. Read more

fn try_fold<T, Fut, F>(self, init: T, f: F) -> TryFold<Self, Fut, T, F> where
    F: FnMut(T, Self::Ok) -> Fut,
    Fut: TryFuture<Ok = T, Error = Self::Error>, [src]

Attempt to execute an accumulating asynchronous computation over a stream, collecting all the values into one final result. Read more

fn try_concat(self) -> TryConcat<Self> where
    Self::Ok: Extend<<Self::Ok as IntoIterator>::Item>,
    Self::Ok: IntoIterator,
    Self::Ok: Default, [src]

Attempt to concatenate all items of a stream into a single extendable destination, returning a future representing the end result. Read more

fn try_buffer_unordered(self, n: usize) -> TryBufferUnordered<Self> where
    Self::Ok: TryFuture,
    <Self::Ok as TryFuture>::Error == Self::Error, [src]

Attempt to execute several futures from a stream concurrently. Read more

fn try_poll_next_unpin(
    &mut self,
    waker: &Waker
) -> Poll<Option<Result<Self::Ok, Self::Error>>> where
    Self: Unpin, [src]

A convenience method for calling [TryStream::poll_next_unpin] on [Unpin] stream types. Read more

ⓘImportant traits for Compat<R>
fn compat(self) -> Compat<Self> where
    Self: Unpin, [src]

Wraps a [TryStream] into a stream compatible with libraries using futures 0.1 Stream. Requires the compat feature to be enabled. ``` #![feature(async_await, await_macro, futures_api)] use futures::future::{FutureExt, TryFutureExt}; # let (tx, rx) = futures::channel::oneshot::channel(); Read more

fn into_async_read(self) -> IntoAsyncRead<Self> where
    Self: TryStreamExt<Error = Error> + Unpin,
    Self::Ok: AsRef<[u8]>, [src]

Adapter that converts this stream into an [AsyncRead]. Read more