com.github.jparkie.promise.extras

Class ExtraPromises

java.lang.Object

com.github.jparkie.promise.extras.ExtraPromises

public final class ExtraPromises
extends java.lang.Object

A helper class for Promise. Provides helper methods for coordinating multiple promises.

Method Summary

Modifier and Type	Method and Description
static <T> Promise<T>	firstCompletedOf(Scheduler scheduler, Promise<T>... promises) Returns a new promise which completes upon the first completion of any promise.
static Promise<java.lang.Void>	whenAll(Scheduler scheduler, Promise<?>... promises) Returns a new promise which waits for the successful completion of all provided promises.
static <T,U> Promise<Pair<T,U>>	zip(Scheduler scheduler, Promise<T> tPromise, Promise<U> uPromise) Zips two promises into one promise.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

firstCompletedOf

public static <T> Promise<T> firstCompletedOf(Scheduler scheduler,
                                              Promise<T>... promises)

Returns a new promise which completes upon the first completion of any promise. The notice of completion of the provided promises are synchronzied. If all of the provided promises cancel, the new promise cancels.

Type Parameters:

T - The type of the value promised to be available now, or in the future, or never.

Parameters:

scheduler - The scheduler under which to operate.

promises - The promises to wait upon.

Returns:

The first completed promise.

whenAll

public static Promise<java.lang.Void> whenAll(Scheduler scheduler,
                                              Promise<?>... promises)

Returns a new promise which waits for the successful completion of all provided promises. The notice of completion of the provided promises are synchronzied. If any of the provided promises cancel, the new promise cancels. If any of the provided promises fail, the new promise fails with the first failure.

Parameters:

scheduler - The scheduler under which to operate.

promises - The promises to wait upon.

Returns:

THe new promise which waits on all the promises.

zip

public static <T,U> Promise<Pair<T,U>> zip(Scheduler scheduler,
                                           Promise<T> tPromise,
                                           Promise<U> uPromise)

Zips two promises into one promise. The cancellation of any of the promises will cancel the zipped promise. The failure of any of the promises will propagate the first failure.

Type Parameters:

T - The left type.

U - The right type.

Parameters:

scheduler - The scheduler under which to operate.

tPromise - The left promise to zip.

uPromise - The right promise to zip.

Returns:

The zipped promise of the left and the right.