List types

Is there a way to make a list that contains multiple types? If not, why, and isn't this a serious restriction? I would like to be able to say: map show ['a',5] Since both Char and Num derive Show it seems like a reasonable thing to do. I realise classes in haskell don't work this way so I guess my question is, why not? Could I do something like this in O'Haskell, Clean, or some other functional language? In particular I am interested in exploring software engineering implications of monadic IO, separation of concerns, etc... Eric Wohlstadter UCDavis Software Engineering