Oh hey, that's pretty nice! I'm a big fan of how the functional languages I've gone further than dabbling in are very pushy about covering all cases for pattern matches (basically switch on steroids), even if sometimes the correct answer is to just throw in a catch-all.

Mostly because it forces you upfront to make sure you're considering every case, and it looks like those warnings ought to give me the same kind of nagging with C and enums.