MapIterator.php

<?php
 
namespace Guzzle\Iterator;
 
use Guzzle\Common\Exception\InvalidArgumentException;
 
class MapIterator extends \IteratorIterator
{
    protected $callback;
 
    public function __construct(\Traversable $iterator, $callback)
    {
        parent::__construct($iterator);
        if (!is_callable($callback)) {
            throw new InvalidArgumentException('The callback must be callable');
        }
        $this->callback = $callback;
    }
 
    public function current()
    {
        return call_user_func($this->callback, parent::current());
    }
}