[srcreigh]

Excellent. Can't wait to try it out.

It's exciting to think of "Deep" checking as a complement to optional checking. Use a mix of both in one code base to play their strengths. For example it'd be great to define a deep type checked module for parsing data. You get static errors and runtime validation too. But, also, use that module from an optionally type checked module, which doesn't add any extra runtime costs if some of your other code / dependencies are untyped.