Future companion object.
Attributes
- Companion
- trait
- Source
- Future.scala
- Graph
- Supertypes
- Self type
- Future.type
Members list
Value members
Concrete methods
Starts an asynchronous computation and returns aFuture instance with the result of that computation.
Starts an asynchronous computation and returns aFuture 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
Futureholding the result of the computation- Source
- Future.scala
Starts an asynchronous computation and returns aFuture instance with the result of that computation once it completes.
Starts an asynchronous computation and returns aFuture instance with the result of that computation once it completes.
The following expressions are semantically equivalent:
val f1 = Future(expr).flattenval 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
bodyis evaluated in
Attributes
- Returns
the
Futureholding the result of the computation- Source
- Future.scala
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
Futureinstance- Source
- Future.scala
Asynchronously and non-blockingly returns aFuture that will hold the optional result of the firstFuture with a result that matches the predicate, failedFutures will be ignored.
Asynchronously and non-blockingly returns aFuture that will hold the optional result of the firstFuture with a result that matches the predicate, failedFutures will be ignored.
Type parameters
- T
the type of the value in the future
Value parameters
- futures
the
scala.collection.immutable.Iterableof Futures to search- p
the predicate which indicates if it's a match
Attributes
- Returns
the
Futureholding the optional result of the search- Source
- Future.scala
Asynchronously and non-blockingly returns a newFuture to the result of the first future in the list that is completed.
Asynchronously and non-blockingly returns a newFuture 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
IterableOnceof Futures in which to find the first completed
Attributes
- Returns
the
Futureholding the result of the future that is first to be completed- Source
- Future.scala
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.Iterableof 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
Futureholding the result of the fold- Source
- Future.scala
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
Futureinstance
Attributes
- Returns
the newly created
Futureinstance- Source
- Future.scala
Initiates a non-blocking, asynchronous, left reduction over the supplied futures where the zero is the result value of the firstFuture.
Initiates a non-blocking, asynchronous, left reduction over the supplied futures where the zero is the result value of the firstFuture.
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.Iterableof Futures to be reduced- op
the reduce operation which is applied to the results of the futures
Attributes
- Returns
the
Futureholding the result of the reduce- Source
- Future.scala
Simple version ofFuture.traverse.
Simple version ofFuture.traverse. Asynchronously and non-blockingly transforms, in essence, aIterableOnce[Future[A]] into aFuture[IterableOnce[A]]. Useful for reducing manyFutures into a singleFuture.
Type parameters
- A
the type of the value inside the Futures
- CC
the type of the
IterableOnceof Futures- To
the type of the resulting collection
Value parameters
- in
the
IterableOnceof Futures which will be sequenced
Attributes
- Returns
the
Futureof the resulting collection- Source
- Future.scala
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
Futureinstance- Source
- Future.scala
Asynchronously and non-blockingly transforms aIterableOnce[A] into aFuture[IterableOnce[B]] using the provided functionA => Future[B].
Asynchronously and non-blockingly transforms aIterableOnce[A] into aFuture[IterableOnce[B]] using the provided functionA => 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
Futureof the collection of results- Source
- Future.scala
Deprecated methods
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
IterableOnceof 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
Futureholding the result of the fold- Deprecated
[Since version 2.12.0]use Future.foldLeft instead- Source
- Future.scala
Initiates a non-blocking, asynchronous, fold over the supplied futures where the fold-zero is the result value of the firstFuture in the collection.
Initiates a non-blocking, asynchronous, fold over the supplied futures where the fold-zero is the result value of the firstFuture 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
IterableOnceof Futures to be reduced- op
the reduce operation which is applied to the results of the futures
Attributes
- Returns
the
Futureholding the result of the reduce- Deprecated
[Since version 2.12.0]use Future.reduceLeft instead- Source
- Future.scala
Concrete fields
A Future which is completed with the Unit value.