Y-combinator in D?

Question

I'm trying to learn the Y-combinator better (I sort of understand it in Scheme) and implement it in D 2.0, and I'm failing pretty miserably:

auto fact = delegate(uint delegate(uint) recurse)
{
    return delegate(uint n)
    {
        return n > 1 ? n * recurse(n - 1) : 1;
    };
};

fact(fact)(5);

This doesn't work, for the obvious reason that I can't pass fact to fact (what would its type be?). And besides, I still need fact's name to pass to itself, so it wouldn't work anyway, right?

But... how do I go about implementing the Y-combinator in D?

Answer 1

See an extensive explanation here.

Answer 2

It's a know limitation of D (and C/C++) that functions that deal with typed self references are impossible (last time I checked) to declare.

I find this ironic because it amounts to a limitation of syntax (the length of the function prototype is infinite) or naming convention (the same problem but with name mangling) rather than anything semantic or architectural.