I haven't seen them, thanks! > Type checking unrestricted message passing would be difficult, but I can imagine a subset that's typeable. I'd love to see a di

I haven't seen them, thanks! > Type checking unrestricted message passing would be difficult, but I can imagine a subset that's typeable. I'd love to see a discussion on this somewhere. I can totally imagine a world where it's true that "yes, you can't send messages of type X because the receiver can't pattern match on them in the way you expect, but what you're really trying to do is Y, and you _can_ send messages of type Z that accomplish Y."