Future (original) (raw)
A Future which is never completed.
A Future which is never completed.
Attributes
Source
Supertypes
Self type
Starts an asynchronous computation and returns a Future instance with the result of that computation.
Starts an asynchronous computation and returns a Future instance with the result of that computation.
The following expressions are equivalent:
val f1 = Future(expr)
val f2 = Future.unit.map(_ => expr)
val f3 = Future.unit.transform(_ => Success(expr))
The result becomes available once the asynchronous computation is completed.
Type parameters
T
the type of the result
Value parameters
body
the asynchronous computation
executor
the execution context on which the future is run
Attributes
Returns
the Future holding the result of the computation
Source
Starts an asynchronous computation and returns a Future instance with the result of that computation once it completes.
Starts an asynchronous computation and returns a Future instance with the result of that computation once it completes.
The following expressions are semantically equivalent:
val f1 = Future(expr).flatten
val f2 = Future.delegate(expr)
val f3 = Future.unit.flatMap(_ => expr)
The result becomes available once the resulting Future of the asynchronous computation is completed.
Type parameters
T
the type of the result
Value parameters
body
the asynchronous computation, returning a Future
executor
the execution context on which the body is evaluated in
Attributes
Returns
the Future holding the result of the computation
Source
Creates an already completed Future with the specified exception.
Creates an already completed Future with the specified exception.
Type parameters
T
the type of the value in the future
Value parameters
exception
the non-null instance of Throwable
Attributes
Returns
the newly created Future instance
Source
Asynchronously and non-blockingly returns a Future that will hold the optional result of the first Future with a result that matches the predicate, failed Futures will be ignored.
Asynchronously and non-blockingly returns a Future that will hold the optional result of the first Future with a result that matches the predicate, failed Futures will be ignored.
Type parameters
T
the type of the value in the future
Value parameters
futures
the scala.collection.immutable.Iterable of Futures to search
p
the predicate which indicates if it's a match
Attributes
Returns
the Future holding the optional result of the search
Source
Asynchronously and non-blockingly returns a new Future to the result of the first future in the list that is completed.
Asynchronously and non-blockingly returns a new Future to the result of the first future in the list that is completed. This means no matter if it is completed as a success or as a failure.
Type parameters
T
the type of the value in the future
Value parameters
futures
the IterableOnce of Futures in which to find the first completed
Attributes
Returns
the Future holding the result of the future that is first to be completed
Source
A non-blocking, asynchronous left fold over the specified futures, with the start value of the given zero.
A non-blocking, asynchronous left fold over the specified futures, with the start value of the given zero. The fold is performed asynchronously in left-to-right order as the futures become completed. The result will be the first failure of any of the futures, or any failure in the actual fold, or the result of the fold.
Example:
val futureSum = Future.foldLeft(futures)(0)(_ + _)
Type parameters
R
the type of the value of the returned Future
T
the type of the value of the input Futures
Value parameters
futures
the scala.collection.immutable.Iterable of Futures to be folded
op
the fold operation to be applied to the zero and futures
zero
the start value of the fold
Attributes
Returns
the Future holding the result of the fold
Source
Creates an already completed Future with the specified result or exception.
Creates an already completed Future with the specified result or exception.
Type parameters
T
the type of the value in the Future
Value parameters
result
the result of the returned Future instance
Attributes
Returns
the newly created Future instance
Source
Initiates a non-blocking, asynchronous, left reduction over the supplied futures where the zero is the result value of the first Future.
Initiates a non-blocking, asynchronous, left reduction over the supplied futures where the zero is the result value of the first Future.
Example:
val futureSum = Future.reduceLeft(futures)(_ + _)
Type parameters
R
the type of the value of the returned Future
T
the type of the value of the input Futures
Value parameters
futures
the scala.collection.immutable.Iterable of Futures to be reduced
op
the reduce operation which is applied to the results of the futures
Attributes
Returns
the Future holding the result of the reduce
Source
Simple version of Future.traverse.
Simple version of Future.traverse. Asynchronously and non-blockingly transforms, in essence, a IterableOnce[Future[A]] into a Future[IterableOnce[A]]. Useful for reducing many Futures into a single Future.
Type parameters
A
the type of the value inside the Futures
CC
the type of the IterableOnce of Futures
To
the type of the resulting collection
Value parameters
in
the IterableOnce of Futures which will be sequenced
Attributes
Returns
the Future of the resulting collection
Source
Creates an already completed Future with the specified result.
Creates an already completed Future with the specified result.
Type parameters
T
the type of the value in the future
Value parameters
result
the given successful value
Attributes
Returns
the newly created Future instance
Source
Asynchronously and non-blockingly transforms a IterableOnce[A] into a Future[IterableOnce[B]] using the provided function A => Future[B].
Asynchronously and non-blockingly transforms a IterableOnce[A] into a Future[IterableOnce[B]] using the provided function A => Future[B]. This is useful for performing a parallel map. For example, to apply a function to all items of a list in parallel:
val myFutureList = Future.traverse(myList)(x => Future(myFunc(x)))
Type parameters
A
the type of the value inside the Futures in the collection
B
the type of the value of the returned Future
M
the type of the collection of Futures
Value parameters
fn
the function to be mapped over the collection to produce a collection of Futures
in
the collection to be mapped over with the provided function to produce a collection of Futures that is then sequenced into a Future collection
Attributes
Returns
the Future of the collection of results
Source
A non-blocking, asynchronous fold over the specified futures, with the start value of the given zero.
A non-blocking, asynchronous fold over the specified futures, with the start value of the given zero. The fold is performed on the thread where the last future is completed, the result will be the first failure of any of the futures, or any failure in the actual fold, or the result of the fold.
Example:
val futureSum = Future.fold(futures)(0)(_ + _)
Type parameters
R
the type of the value of the returned Future
T
the type of the value of the input Futures
Value parameters
futures
the IterableOnce of Futures to be folded
op
the fold operation to be applied to the zero and futures
zero
the start value of the fold
Attributes
Returns
the Future holding the result of the fold
Deprecated
[Since version 2.12.0] use Future.foldLeft instead
Source
Initiates a non-blocking, asynchronous, fold over the supplied futures where the fold-zero is the result value of the first Future in the collection.
Initiates a non-blocking, asynchronous, fold over the supplied futures where the fold-zero is the result value of the first Future in the collection.
Example:
val futureSum = Future.reduce(futures)(_ + _)
Type parameters
R
the type of the value of the returned Future
T
the type of the value of the input Futures
Value parameters
futures
the IterableOnce of Futures to be reduced
op
the reduce operation which is applied to the results of the futures
Attributes
Returns
the Future holding the result of the reduce
Deprecated
[Since version 2.12.0] use Future.reduceLeft instead
Source
A Future which is completed with the Unit value.
A Future which is completed with the Unit value.
Attributes
Source