I can second ocaml. Im using it more lately and really enjoying it. Of course the compiler error message leaves a lot of room for improvement. And it does ta

I can second ocaml. Im using it more lately and really enjoying it. Of course the compiler error message leaves a lot of room for improvement. And it does take a lot of time to get used to all of the peculiar syntax. But you get ADTs, the best modules on earth (even if the syntax is a bit old ...), GADT if you want them, object row polymorphism, polymorphic variants, streams, etc.