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Tip revision: 47f62ac0c09ea198ee3a32c1416fe4f914ed597e authored by Boris Zbarsky on 17 April 2012, 17:30:07 UTC
Merge backout of changeset ca80d75dbcb1 (which was a backout of bug 734019) in an attempt to fix bug 734019. a=akeybl
Tip revision: 47f62ac
Y.js
// The Y combinator, applied to the factorial function

function factorial(proc) {
    return function (n) {
        return (n <= 1) ? 1 : n * proc(n-1);
    }
}

function Y(outer) {
    function inner(proc) {
        function apply(arg) {
            return proc(proc)(arg);
        }
        return outer(apply);
    }
    return inner(inner);
}

print("5! is " + Y(factorial)(5));
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