/* This Source Code Form is subject to the terms of the Mozilla Public | |
* License, v. 2.0. If a copy of the MPL was not distributed with this | |
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
// The Y combinator, applied to the factorial function | |
// Return the function that is the fixed point of f. | |
var Y = f => (x => f(v => x(x)(v))) | |
(x => f(v => x(x)(v))); | |
// The factorial function is the fixed point of this: | |
var f = fac => n => (n <= 1) ? 1 : n * fac(n - 1); | |
print("5! is " + Y(f)(5)); |