I've been trying to get this idea right for almost two years now. On two occasions I've even reached the point where I thought I was ready to let code loose on the world, but then I discovered something which I wasn't able to handle without duplicating the references in a hash, which completely negates any benefit at all.

As I said, I have the germ of a solution, but as I am entirely uncomfortable in using XS, or even XS modules in ways that move beyond their authors intent, it will remain just an idea until I can think of a way of proving it's safety.