Hi, I'm trying to do something like the following: class Foo a where doit :: (String -> IO ()) -> a -> IO () instance Foo Int where doit f = f . show instance Foo Char where doit f = f . (:[]) So now I have a "doit" function for Ints and Chars, that takes a function and does the IO with the given function. Now I could define function p as p :: (Foo a) => a -> IO () p = doit putStrLn so I could do main = do p 3 p 'X' in main, but I would like to compeltely hide the fact from p that it somehow belongs to the Foo class, so I would like to do something like this: class Foo a => Bar a where p2 :: a -> IO () p2 = doit putStrln but, though Foo Int and Foo Char are defined, Bar Int and Bar Char are not defined automatically, so given this class definition I will not be able to call p2 3 and p2 'X' Is there still some way to do something like this? Thanks, Istvan