"smacked in the face" might be a bit extreme, but I can sympathise with GP's point. I read the first line of the first example:

    A :: ~ * ~> * => {(list A) :: |new |empty }.

And got stuck at the first hurdle. I started parsing it in my mind and read "A such that tilde star arrow tilde double arrow". I stopped there, and thought "I'm lost". I started trying to interpret it: * might mean wildcard; single arrow could be curried functions (per Haskell). But I don't know what tilde means, nor the double arrow.

Now, of course, I can go and look it up: it'll all be defined somewhere. But that first experience - that very first "I've never seen this before, it sounds interesting" hit a road block right there.

Maybe not smacked in the face, but enough friction for me to click the back button.