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amp/lib/Promisor.php
2015-07-07 10:15:57 -04:00

73 lines
2.2 KiB
PHP

<?php
namespace Amp;
/**
* A Promisor represents a contract to resolve a deferred value at some point in the future
*
* A Promisor resolves its associated placeholder value (Promise) Promisor::succeed() or
* Promisor::fail(). Promisor::update() may be used to notify watchers of progress resolving
* the deferred value.
*
* Example:
*
* function myAsyncProducer() {
* // Create a new promisor that needs to be resolved
* $promisor = new Amp\Deferred;
*
* // When we eventually finish non-blocking value resolution we
* // simply call the relevant Promise method to notify any code
* // with references to the Promisor's associated Promise:
* // $promisor->succeed($value) -or- $promisor->fail($exceptionObj)
*
* return $promisor->promise();
* }
*
* The following correlations exist between Promisor and Promise methods:
*
* - Promisor::update | Promise::watch
* - Promisor::succeed | Promise::when
* - Promisor::fail | Promise::when
*/
interface Promisor {
/**
* Promise deferred fulfillment via a temporary placeholder value
*
* @return \Amp\Promise
*/
public function promise();
/**
* Update watchers of progress resolving the promised value
*
* Implementations must support variadic argument passing to update
* even though 5.5-compatibility prevents us from specifying it as
* part of the API.
*
* @param mixed $progress1, $progress2, ... $progressN
* @return void
*/
public function update($progress);
/**
* Resolve the promised value as a success
*
* @param mixed $result
* @return void
*/
public function succeed($result = null);
/**
* Resolve the promised value as a failure
*
* The error parameter used to fail a promisor must always be an exception
* instance. However, we cannot typehint this parameter in environments
* where PHP5.x compatibility is required because PHP7 Throwable
* instances will break the typehint.
*
* @param mixed $error An Exception or Throwable in PHP7 environments
* @return void
*/
public function fail($error);
}