Cleaner, yes. I picked OCaml because it seemed easier to find information about, and more widely ported.

Also, I think most people fail to appreciate how useful compiler techniques are outside of "compilers". Even just knowing a little about lexing and parsing goes a long way.

For Prolog, I'd also recommend _The Art of Prolog_ by Sterling & Shapiro and/or Clocksin's _Clause & Effect_.