Warning - dangerous nerdery ahead!

[pmb]

def voodoo(f):
    def A(x):
        def B(y):
            return x(x)(y)
        return f(B)
    return A(A)

def hypothetical_fact(factorial):
    def f(n):
        if n == 0:
            return 1
        else:
            return n * factorial(n-1)
    return f

fact = voodoo(hypothetical_fact)

print fact(30)

The Z combinator is messed up. Anybody want to explain the above code to me?

Comments

Re: I'll give it a shot...

[stereotype441.livejournal.com]

Hmm... On second reading, I don't think I got that second paragraph exactly right. Instead of saying "But it does it without using any recursive functions" I should have said "But it does it without using any self-referential functions". Oops.