Iterator Map

iterator_map.php

<?php

function iterator_map($iterator, $callback)
{
	$result = array();
	foreach ($iterator as $key => $current) {
		$result[$key] = $callback($current, $key, $iterator);
	}
	return $result;
}

$files  = new LimitIterator(new FilesystemIterator(__DIR__), 0, 10);
$mapped = iterator_map($files, function($c){ return $c->getSize(); });
var_dump($mapped);