IteratorAggregate
IteratorAggregate is an interface to create a custom iterator.
It requires a single method, that returns an iterator that will be used with PHP native functions.
It also suggest that several iterators may be merged in one, by creating a class that merges them.
<?php
declare(strict_types=1);
class MergedIteratorAggregate implements IteratorAggregate
{
/** @var iterable[] */
private array $iterables = [];
public function addIterable(iterable $iterable): void
{
$this->iterables[] = $iterable;
}
public function getIterator(): Traversable
{
foreach ($this->iterables as $iterable) {
// yield from works with arrays AND Traversable objects
yield from $iterable;
}
}
}
$x = new MergedIteratorAggregate();
function foo() {
yield rand(0, 10);
}
// Using iterator with generators
$x->addIterable(foo());
$x->addIterable(foo());
foreach($x as $y) {
print $y.PHP_EOL;
}
?>