gistfile1.txt

func map(xs, f, go result = list()) {
    if empty?(xs) {
        result;
    } else {
        go(tail(xs), f, f(head(xs)) :: result);
    };
}

// is sugar for

func map(xs, f) {
    func __go(xs, f, result) {
        if empty?(xs) {
            result;
        } else {
            __go(tail(xs), f, f(head(xs)) :: result);
        };
    }
    __go(xs, f, list());
}