I’m fairly sure there’s ocaml in haikuports. It looks as though Erlang is in there too. I suspect you might have trouble boot strapping haskell? If you like logic programming, I have ported SWI Prolog, it has almost identical syntax to Erlang (Erlang syntax is based on prolog, in fact early versions were developed in it).
Note that none of these have bindings for the haiku API, as far as I know, so GUI programming would not be easy (I guess if they have qt bindings it might work with the qt port… swipl does not, not sure about the others).