almost.functional.reactive

Class Promise<T>

java.lang.Object

almost.functional.reactive.Promise<T>

Type Parameters:

T - the type the supplier is committed to provide.

All Implemented Interfaces:

java.lang.Runnable

public class Promise<T>
extends java.lang.Object
implements java.lang.Runnable

A Promise is a composite of a Supplier and an Observer allowing for observation or the supplier.

This implements Runnable so that it can be tucked into a Future etc. Once the Observer is completed it is released.

See Also:

Observer, Consumer, Supplier

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Promise.State The current state of the promise.

Constructor Summary

Constructors

Constructor and Description
Promise(Supplier<T> supplier, Observer<T> observer) Create a Promise based on a given supplier and with an Observer.

Method Summary

Methods

Modifier and Type	Method and Description
Promise.State	getState() Get the current state of this promise.
void	run() This method calls the supplier and on successful completion informs the fulfilled consumers of the return value.

Methods inherited from class java.lang.Object

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

Constructor Detail

Promise

public Promise(Supplier<T> supplier,
       Observer<T> observer)

Create a Promise based on a given supplier and with an Observer.

Parameters:

supplier - the supplier

Method Detail

run

public void run()

This method calls the supplier and on successful completion informs the fulfilled consumers of the return value. If the supplier throws an exception the rejected consumers are informed. In either case when the call to the supplier completes the settled consumers are informed with an Optional containing the supplied value on success.

Specified by:

run in interface java.lang.Runnable

getState

public Promise.State getState()

Get the current state of this promise.

Returns:

the state