Nasal-Interpreter/test/ycombinator.nas

# Y combinator by ValKmjolnir
var fib = func(f) {
    return f(f);
}(
    func(f) {
        return func(x) {
            if (x < 2) return x;
            var tmp = f(f);
            return tmp(x - 1) + tmp(x - 2);
        }
    }
);

for (var i = 1; i < 31; i += 1) {
    println(fib(i));
}