As promised, a word on the newest typecheck derivative, type_algebra.

type_algebra is being spun off to hold things like Xor(), Not(), Any(), i.e., things that are more neat than they are useful. It also serves as a good, easy example of how to extend typecheck for one’s own ends.

With this in mind, a few other things are going in: first up, a Nothing() class to complement Any() — where as Any() approves everything, Nothing() approves, well, nothing.

I’m probably going to add smarter versions of And() and Or() classes with beefed up intelligence as to how to simplify certain types of type expressions. Again, things that are cooler/interesting than they are useful/practical.

While tarballs aren’t yet available (type_algebra will ship with typecheck 0.4.0), you can follow along at home via the WebSVN viewer.