public static function perform($string, $keys, $values = null) { if ($values === null) { self::$tokens = $keys; } else { self::$tokens = array_combine($keys, $value); } return preg_replace('/[\\\\]{1}(\\{[0-9A-Za-z-_]+\\})/', '\\1', preg_replace_callback('/([^\\\\]{1})(\\{[0-9A-Za-z-_]+\\})/', 'Tokenizer::replace', $string)); }