recursion with an unnamed lambda via fancy pants fixed point combinator

gistfile1.txt

func fixedPoint<S,T>(f:(S->T) -> (S->T)) -> (S->T) {
    return {
        (x : S) -> T in
        return f(fixedPoint(f))(x)
    }
}

let fact:(Int)->Int = fixedPoint {
    (almostFactorial:(Int)->Int) -> ((Int)->Int) in
    return {
        (n : Int) -> Int in
        if n == 0 {
            return 1
        } else {
            return n * almostFactorial(n-1);
        }
    }
}

println("\(fact(5))")