Struct async_observable::Observable
source · pub struct Observable<T>where
T: Clone,{ /* private fields */ }
Expand description
Wraps a value and lets you fork the state to synchronize it between tasks and threads.
§Creating New Observables
There are several ways to create a new observable, altough using the new
function should be
the preferred way.
let mut using_new = Observable::new(0);
let mut using_from = Observable::from(0);
let mut using_into: Observable<u8> = 0.into();
§Publishing New Values
Publishing a new version is done by a single call to the publish()
method.
observable.publish(1);
observable.publish(2);
observable.publish(3);
§Receiving Updates
let mut observable = Observable::new(0);
let mut fork = observable.clone();
observable.publish(1);
observable.publish(2);
observable.publish(3);
assert_eq!(fork.next().await, 3);
§Important
Keep in mind that if you publish multiple versions directly after each other there no
guarantees that all forked observables will receive every change! But as long as every
observable is constently asking for changes (via next()
) you are guaranteed that every
observable received the latest version.
Implementations§
source§impl<T> Observable<T>where
T: Clone,
impl<T> Observable<T>where
T: Clone,
sourcepub fn modify_conditional<C, M>(&mut self, condition: C, modify: M) -> bool
pub fn modify_conditional<C, M>(&mut self, condition: C, modify: M) -> bool
If the condition is met, modify the underlying value and notify forks.
Returns true
if the modification was executed.
let mut observable = Observable::new(0);
let mut fork = observable.clone();
observable.modify_conditional(|i| *i == 0, |i| *i = 1); // modify
assert_eq!(fork.next().await, 1);
observable.modify_conditional(|i| *i == 0, |i| *i = 2); // doesnt modify
fork.next().await; // runs forever
sourcepub fn clone_and_reset(&self) -> Observable<T>
pub fn clone_and_reset(&self) -> Observable<T>
Same as clone, but the reset causes the fork to instantly have a change available with the current state.
let mut observable = Observable::new(0);
let mut fork = observable.clone_and_reset();
assert_eq!(fork.next().await, 0);
sourcepub fn reset(&mut self)
pub fn reset(&mut self)
Resets the observable to instantly have a change available
let (mut observable, mut fork) = Observable::new(0).split();
fork.reset();
assert_eq!(fork.next().await, 0);
sourcepub fn latest(&self) -> T
pub fn latest(&self) -> T
Creates a clone of latest version of the observable value, without consuming the change!
let mut observable = Observable::new(0);
let mut fork = observable.clone_and_reset();
observable.publish(1);
assert_eq!(fork.latest(), 1);
assert_eq!(fork.next().await, 1);
sourcepub async fn next(&mut self) -> T
pub async fn next(&mut self) -> T
Wait until a new version of the observable was published and return a clone of the new version.
let (mut a, mut b) = Observable::new(0).split();
a.publish(1);
assert_eq!(b.next().await, 1);
a.publish(2);
assert_eq!(b.next().await, 2);
b.next().await; // runs forever!
sourcepub fn synchronize(&mut self) -> T
pub fn synchronize(&mut self) -> T
Skip any potential updates and retrieve the latest version of the observed value.
let (mut a, mut b) = Observable::new(0).split();
a.publish(1);
a.publish(2);
a.publish(3);
assert_eq!(b.synchronize(), 3);
b.next().await; // runs forever!
sourcepub fn split(self) -> (Self, Self)
pub fn split(self) -> (Self, Self)
Splits the observable into two handles to the same value
This is very useful if you are spawning threads or tasks which get an owned instance of the observable
let (mut main, mut task) = Observable::new(0).split();
async_std::task::spawn(async move {
task.publish(1);
});
assert_eq!(main.next().await, 1);
source§impl<T> Observable<T>
impl<T> Observable<T>
sourcepub fn publish_if_changed(&mut self, value: T) -> bool
pub fn publish_if_changed(&mut self, value: T) -> bool
Publish a change if the new value differs from the current one.
Returns true
if a change was made.
Trait Implementations§
source§impl<T> Clone for Observable<T>
impl<T> Clone for Observable<T>
source§fn clone(&self) -> Observable<T>
fn clone(&self) -> Observable<T>
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl<T> Debug for Observable<T>
impl<T> Debug for Observable<T>
source§impl<T> Drop for Observable<T>where
T: Clone,
impl<T> Drop for Observable<T>where
T: Clone,
source§impl<T> From<T> for Observable<T>where
T: Clone,
impl<T> From<T> for Observable<T>where
T: Clone,
source§impl<T> PartialEq for Observable<T>
impl<T> PartialEq for Observable<T>
source§impl<T> Stream for Observable<T>where
T: Clone,
impl<T> Stream for Observable<T>where
T: Clone,
impl<T> Eq for Observable<T>
Auto Trait Implementations§
impl<T> Freeze for Observable<T>
impl<T> RefUnwindSafe for Observable<T>
impl<T> Send for Observable<T>where
T: Send,
impl<T> Sync for Observable<T>where
T: Send,
impl<T> Unpin for Observable<T>
impl<T> UnwindSafe for Observable<T>
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
source§impl<T> StreamExt for T
impl<T> StreamExt for T
source§fn next(&mut self) -> Next<'_, Self>where
Self: Unpin,
fn next(&mut self) -> Next<'_, Self>where
Self: Unpin,
source§fn into_future(self) -> StreamFuture<Self>
fn into_future(self) -> StreamFuture<Self>
source§fn map<T, F>(self, f: F) -> Map<Self, F>
fn map<T, F>(self, f: F) -> Map<Self, F>
source§fn enumerate(self) -> Enumerate<Self>where
Self: Sized,
fn enumerate(self) -> Enumerate<Self>where
Self: Sized,
source§fn filter<Fut, F>(self, f: F) -> Filter<Self, Fut, F>
fn filter<Fut, F>(self, f: F) -> Filter<Self, Fut, F>
source§fn filter_map<Fut, T, F>(self, f: F) -> FilterMap<Self, Fut, F>
fn filter_map<Fut, T, F>(self, f: F) -> FilterMap<Self, Fut, F>
source§fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F>
fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F>
source§fn collect<C>(self) -> Collect<Self, C>
fn collect<C>(self) -> Collect<Self, C>
source§fn unzip<A, B, FromA, FromB>(self) -> Unzip<Self, FromA, FromB>
fn unzip<A, B, FromA, FromB>(self) -> Unzip<Self, FromA, FromB>
source§fn concat(self) -> Concat<Self>
fn concat(self) -> Concat<Self>
source§fn count(self) -> Count<Self>where
Self: Sized,
fn count(self) -> Count<Self>where
Self: Sized,
source§fn fold<T, Fut, F>(self, init: T, f: F) -> Fold<Self, Fut, T, F>
fn fold<T, Fut, F>(self, init: T, f: F) -> Fold<Self, Fut, T, F>
source§fn any<Fut, F>(self, f: F) -> Any<Self, Fut, F>
fn any<Fut, F>(self, f: F) -> Any<Self, Fut, F>
true
if any element in stream satisfied a predicate. Read moresource§fn all<Fut, F>(self, f: F) -> All<Self, Fut, F>
fn all<Fut, F>(self, f: F) -> All<Self, Fut, F>
true
if all element in stream satisfied a predicate. Read moresource§fn flatten(self) -> Flatten<Self>
fn flatten(self) -> Flatten<Self>
source§fn flatten_unordered(
self,
limit: impl Into<Option<usize>>
) -> FlattenUnorderedWithFlowController<Self, ()>
fn flatten_unordered( self, limit: impl Into<Option<usize>> ) -> FlattenUnorderedWithFlowController<Self, ()>
source§fn flat_map_unordered<U, F>(
self,
limit: impl Into<Option<usize>>,
f: F
) -> FlatMapUnordered<Self, U, F>
fn flat_map_unordered<U, F>( self, limit: impl Into<Option<usize>>, f: F ) -> FlatMapUnordered<Self, U, F>
StreamExt::map
but flattens nested Stream
s
and polls them concurrently, yielding items in any order, as they made
available. Read moresource§fn scan<S, B, Fut, F>(self, initial_state: S, f: F) -> Scan<Self, S, Fut, F>
fn scan<S, B, Fut, F>(self, initial_state: S, f: F) -> Scan<Self, S, Fut, F>
StreamExt::fold
that holds internal state
and produces a new stream. Read moresource§fn skip_while<Fut, F>(self, f: F) -> SkipWhile<Self, Fut, F>
fn skip_while<Fut, F>(self, f: F) -> SkipWhile<Self, Fut, F>
true
. Read moresource§fn take_while<Fut, F>(self, f: F) -> TakeWhile<Self, Fut, F>
fn take_while<Fut, F>(self, f: F) -> TakeWhile<Self, Fut, F>
true
. Read moresource§fn take_until<Fut>(self, fut: Fut) -> TakeUntil<Self, Fut>
fn take_until<Fut>(self, fut: Fut) -> TakeUntil<Self, Fut>
source§fn for_each<Fut, F>(self, f: F) -> ForEach<Self, Fut, F>
fn for_each<Fut, F>(self, f: F) -> ForEach<Self, Fut, F>
source§fn for_each_concurrent<Fut, F>(
self,
limit: impl Into<Option<usize>>,
f: F
) -> ForEachConcurrent<Self, Fut, F>
fn for_each_concurrent<Fut, F>( self, limit: impl Into<Option<usize>>, f: F ) -> ForEachConcurrent<Self, Fut, F>
source§fn take(self, n: usize) -> Take<Self>where
Self: Sized,
fn take(self, n: usize) -> Take<Self>where
Self: Sized,
n
items of the underlying stream. Read moresource§fn skip(self, n: usize) -> Skip<Self>where
Self: Sized,
fn skip(self, n: usize) -> Skip<Self>where
Self: Sized,
n
items of the underlying stream. Read moresource§fn catch_unwind(self) -> CatchUnwind<Self>where
Self: Sized + UnwindSafe,
fn catch_unwind(self) -> CatchUnwind<Self>where
Self: Sized + UnwindSafe,
source§fn boxed<'a>(self) -> Pin<Box<dyn Stream<Item = Self::Item> + Send + 'a>>
fn boxed<'a>(self) -> Pin<Box<dyn Stream<Item = Self::Item> + Send + 'a>>
source§fn boxed_local<'a>(self) -> Pin<Box<dyn Stream<Item = Self::Item> + 'a>>where
Self: Sized + 'a,
fn boxed_local<'a>(self) -> Pin<Box<dyn Stream<Item = Self::Item> + 'a>>where
Self: Sized + 'a,
source§fn buffered(self, n: usize) -> Buffered<Self>
fn buffered(self, n: usize) -> Buffered<Self>
source§fn buffer_unordered(self, n: usize) -> BufferUnordered<Self>
fn buffer_unordered(self, n: usize) -> BufferUnordered<Self>
source§fn zip<St>(self, other: St) -> Zip<Self, St>
fn zip<St>(self, other: St) -> Zip<Self, St>
source§fn peekable(self) -> Peekable<Self>where
Self: Sized,
fn peekable(self) -> Peekable<Self>where
Self: Sized,
peek
method. Read moresource§fn chunks(self, capacity: usize) -> Chunks<Self>where
Self: Sized,
fn chunks(self, capacity: usize) -> Chunks<Self>where
Self: Sized,
source§fn ready_chunks(self, capacity: usize) -> ReadyChunks<Self>where
Self: Sized,
fn ready_chunks(self, capacity: usize) -> ReadyChunks<Self>where
Self: Sized,
source§fn forward<S>(self, sink: S) -> Forward<Self, S>
fn forward<S>(self, sink: S) -> Forward<Self, S>
source§fn split<Item>(self) -> (SplitSink<Self, Item>, SplitStream<Self>)
fn split<Item>(self) -> (SplitSink<Self, Item>, SplitStream<Self>)
source§fn inspect<F>(self, f: F) -> Inspect<Self, F>
fn inspect<F>(self, f: F) -> Inspect<Self, F>
source§fn left_stream<B>(self) -> Either<Self, B>
fn left_stream<B>(self) -> Either<Self, B>
source§fn right_stream<B>(self) -> Either<B, Self>
fn right_stream<B>(self) -> Either<B, Self>
source§fn poll_next_unpin(&mut self, cx: &mut Context<'_>) -> Poll<Option<Self::Item>>where
Self: Unpin,
fn poll_next_unpin(&mut self, cx: &mut Context<'_>) -> Poll<Option<Self::Item>>where
Self: Unpin,
Stream::poll_next
on Unpin
stream types.source§fn select_next_some(&mut self) -> SelectNextSome<'_, Self>where
Self: Unpin + FusedStream,
fn select_next_some(&mut self) -> SelectNextSome<'_, Self>where
Self: Unpin + FusedStream,
source§impl<S> TryStreamExt for S
impl<S> TryStreamExt for S
source§fn err_into<E>(self) -> ErrInto<Self, E>
fn err_into<E>(self) -> ErrInto<Self, E>
source§fn map_ok<T, F>(self, f: F) -> MapOk<Self, F>
fn map_ok<T, F>(self, f: F) -> MapOk<Self, F>
source§fn map_err<E, F>(self, f: F) -> MapErr<Self, F>
fn map_err<E, F>(self, f: F) -> MapErr<Self, F>
source§fn and_then<Fut, F>(self, f: F) -> AndThen<Self, Fut, F>
fn and_then<Fut, F>(self, f: F) -> AndThen<Self, Fut, F>
f
. Read moresource§fn or_else<Fut, F>(self, f: F) -> OrElse<Self, Fut, F>
fn or_else<Fut, F>(self, f: F) -> OrElse<Self, Fut, F>
f
. Read moresource§fn inspect_ok<F>(self, f: F) -> InspectOk<Self, F>
fn inspect_ok<F>(self, f: F) -> InspectOk<Self, F>
source§fn inspect_err<F>(self, f: F) -> InspectErr<Self, F>
fn inspect_err<F>(self, f: F) -> InspectErr<Self, F>
source§fn into_stream(self) -> IntoStream<Self>where
Self: Sized,
fn into_stream(self) -> IntoStream<Self>where
Self: Sized,
source§fn try_next(&mut self) -> TryNext<'_, Self>where
Self: Unpin,
fn try_next(&mut self) -> TryNext<'_, Self>where
Self: Unpin,
source§fn try_for_each<Fut, F>(self, f: F) -> TryForEach<Self, Fut, F>
fn try_for_each<Fut, F>(self, f: F) -> TryForEach<Self, Fut, F>
source§fn try_skip_while<Fut, F>(self, f: F) -> TrySkipWhile<Self, Fut, F>
fn try_skip_while<Fut, F>(self, f: F) -> TrySkipWhile<Self, Fut, F>
true
. Read moresource§fn try_take_while<Fut, F>(self, f: F) -> TryTakeWhile<Self, Fut, F>
fn try_take_while<Fut, F>(self, f: F) -> TryTakeWhile<Self, Fut, F>
true
. Read moresource§fn try_for_each_concurrent<Fut, F>(
self,
limit: impl Into<Option<usize>>,
f: F
) -> TryForEachConcurrent<Self, Fut, F>
fn try_for_each_concurrent<Fut, F>( self, limit: impl Into<Option<usize>>, f: F ) -> TryForEachConcurrent<Self, Fut, F>
source§fn try_collect<C>(self) -> TryCollect<Self, C>
fn try_collect<C>(self) -> TryCollect<Self, C>
source§fn try_chunks(self, capacity: usize) -> TryChunks<Self>where
Self: Sized,
fn try_chunks(self, capacity: usize) -> TryChunks<Self>where
Self: Sized,
source§fn try_ready_chunks(self, capacity: usize) -> TryReadyChunks<Self>where
Self: Sized,
fn try_ready_chunks(self, capacity: usize) -> TryReadyChunks<Self>where
Self: Sized,
source§fn try_filter<Fut, F>(self, f: F) -> TryFilter<Self, Fut, F>
fn try_filter<Fut, F>(self, f: F) -> TryFilter<Self, Fut, F>
source§fn try_filter_map<Fut, F, T>(self, f: F) -> TryFilterMap<Self, Fut, F>
fn try_filter_map<Fut, F, T>(self, f: F) -> TryFilterMap<Self, Fut, F>
source§fn try_flatten_unordered(
self,
limit: impl Into<Option<usize>>
) -> TryFlattenUnordered<Self>
fn try_flatten_unordered( self, limit: impl Into<Option<usize>> ) -> TryFlattenUnordered<Self>
source§fn try_flatten(self) -> TryFlatten<Self>
fn try_flatten(self) -> TryFlatten<Self>
source§fn try_fold<T, Fut, F>(self, init: T, f: F) -> TryFold<Self, Fut, T, F>
fn try_fold<T, Fut, F>(self, init: T, f: F) -> TryFold<Self, Fut, T, F>
source§fn try_concat(self) -> TryConcat<Self>
fn try_concat(self) -> TryConcat<Self>
source§fn try_buffer_unordered(self, n: usize) -> TryBufferUnordered<Self>
fn try_buffer_unordered(self, n: usize) -> TryBufferUnordered<Self>
source§fn try_buffered(self, n: usize) -> TryBuffered<Self>
fn try_buffered(self, n: usize) -> TryBuffered<Self>
source§fn try_poll_next_unpin(
&mut self,
cx: &mut Context<'_>
) -> Poll<Option<Result<Self::Ok, Self::Error>>>where
Self: Unpin,
fn try_poll_next_unpin(
&mut self,
cx: &mut Context<'_>
) -> Poll<Option<Result<Self::Ok, Self::Error>>>where
Self: Unpin,
TryStream::try_poll_next
on Unpin
stream types.source§fn into_async_read(self) -> IntoAsyncRead<Self>
fn into_async_read(self) -> IntoAsyncRead<Self>
AsyncBufRead
. Read moresource§fn try_all<Fut, F>(self, f: F) -> TryAll<Self, Fut, F>
fn try_all<Fut, F>(self, f: F) -> TryAll<Self, Fut, F>
Err
is encountered or if an Ok
item is found
that does not satisfy the predicate. Read more