51 lines
936 B
PHP
51 lines
936 B
PHP
<?php
|
|
|
|
namespace WP_Ultimo\Dependencies\Amp;
|
|
|
|
/**
|
|
* A NullCancellationToken can be used to avoid conditionals to check whether a token has been provided.
|
|
*
|
|
* Instead of writing
|
|
*
|
|
* ```php
|
|
* if ($token) {
|
|
* $token->throwIfRequested();
|
|
* }
|
|
* ```
|
|
*
|
|
* potentially multiple times, it allows writing
|
|
*
|
|
* ```php
|
|
* $token = $token ?? new NullCancellationToken;
|
|
*
|
|
* // ...
|
|
*
|
|
* $token->throwIfRequested();
|
|
* ```
|
|
*
|
|
* instead.
|
|
*/
|
|
final class NullCancellationToken implements CancellationToken
|
|
{
|
|
/** @inheritdoc */
|
|
public function subscribe(callable $callback) : string
|
|
{
|
|
return "null-token";
|
|
}
|
|
/** @inheritdoc */
|
|
public function unsubscribe(string $id)
|
|
{
|
|
// nothing to do
|
|
}
|
|
/** @inheritdoc */
|
|
public function isRequested() : bool
|
|
{
|
|
return \false;
|
|
}
|
|
/** @inheritdoc */
|
|
public function throwIfRequested()
|
|
{
|
|
// nothing to do
|
|
}
|
|
}
|