I am not sure if that is correct. When I took Odersky's Functional Programming with Scala class last year, it was recommended that we use the Eclipse based Scala IDE that had live worksheets: save the file and everything on the worksheet gets executed (quickly). I am an old Lisp programmer and the Scala IDE worksheets had the goodness of working in a repl. Compiling homework assignments seemed fast also, but that was only a few hundred lines of code.

BTW, off topic but I would really recommend Odersky's class if it is offered again. I mostly use Clojure now, but the material in the class was generally useful for doing functional programming.