On Tue, Jun 7, 2011 at 16:16, Arnaud Bailly <arnaud.oq...@gmail.com> wrote: > For example, while designing some program (a game...) I defined a type class > thus: > >> class (Monad io) => CommandIO io where >> readCommand :: io Command >> writeResult :: CommandResult -> io ()
This is in fact one of the reasons to use type classes. In fact, you'll find a somewhat more general variety of it on Hackage in a couple of forms, the one I'm most familiar with being MonadPrompt. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe