#unittest {
	name: "loop() for string";
	error: NONE;
	result: "aeiouAEIOU";
};

func main () {
	var s = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";

	var ret = ""
	s.loop(func (c) {
		if (c == "a" or c == "A" or
				c == "e" or c == "E" or
				c == "i" or c == "I" or
				c == "o" or c == "O" or
				c == "u" or c == "U") {
			ret += c;
		}
	})
	return ret;
}