It might seem obvious, but you can return a compiled generator from your IteratorAggregate::getIterator() implementation.
<?php
class Collection implements IteratorAggregate
{
private $items = [];
public function __construct($items = [])
{
$this->items = $items;
}
public function getIterator()
{
return (function () {
while(list($key, $val) = each($this->items)) {
yield $key => $val;
}
})();
}
}
$data = [ 'A', 'B', 'C', 'D' ];
$collection = new Collection($data);
foreach ($collection as $key => $val) {
echo sprintf("[%s] => %s\n", $key, $val);
}
?>
