public static function array_pack ($array, & $vs = null)
{
	$in = $vs === null;
	$as = null;
	foreach ($array as $k => $v)
	{
		if (!isset($vs[$k]))
			$vs[$k] = count($vs);
		
		if (is_array($v))
		{
			$as[] = $vs[$k];
			$as[] = self::array_pack($v, $vs);
		}
		else
		{
			if (!isset($vs[$v]))
				$vs[$v] = count($vs);
			$as[] = $vs[$k];
			$as[] = $vs[$v];
		}
	}
	return $in ? array($as, array_flip($vs)) : $as;
}
Code language: PHP (php)