gistfile1.txt

<?php

// copyright josé 2002
/**
 * @param array $array
 *
 * @return array
 */
public static function cartesianProduct(array $array)
{
    $count = count($array);
    if ($count <= 1) {
        return $count > 0 ? array_map(function ($array) {
            return array($array);
        }, $array[0]) : $array;
    }

    $cartesianProduct = array();

    $last = array_pop($array);
    foreach ($last as $value) {
        foreach (self::cartesianProduct($array) as $toAdd) {
            $cartesianProduct[] = is_array($toAdd) ? array_merge($toAdd, array($value)) : array(
                $toAdd,
                $value
            );
        }
    }

    return $cartesianProduct;
}