Y Combinator JS and Recursive Calls

ycombinator.js

var trampoline = function (f) {
    while (f && f instanceof Function) {
        f = f.apply(f.context, f.args);
    }
    return f;
}

var thunk = function (fn) {
    return function () {
        var args = Array.prototype.slice.apply(arguments);
        return function () {
            return fn.apply(this, args);
        };
    };
};

var Y = function (F) {
    return (function (f) {
        return f(f);
    }(function (f) {
        return F(function (x) {
            return f(f)(x);
        });
    }));
};


var FactorialGen2 = function () {
    return function (n) {
        var factorial = thunk(function (x, n) {
            if (n == 0) {
                return x;
            }
            else {
                return factorial(n * x, n - 1);
            }
        });
        return trampoline(factorial(1, n));
    }
};

var Factorial2 = Y(FactorialGen2)
console.log(Factorial2(10)); // 3628800
console.log(Factorial2(23456)); // Infinity but works

var Sum = function () {
    return function (n) {
        var sum = thunk(function (acc, n) {
            if (n == 0) return acc
            else return sum(acc + n, n - 1)
        })
        return trampoline(sum(0, n))
    }
}

console.log(Y(Sum)(25000))

holy shit!