PHP Memoization

php_memoize.php

<?php

function memoize(&$callback){
	return $callback =  function() use ($callback,$cache){
		static $cache = array();
		$args = func_get_args();
		$hash_key = implode(',',$args);
		return isset($cache[$hash_key])?$cache[$hash_key]:$cache[$hash_key]=call_user_func_array($callback, $args);
	};
}