Thanks! These examples and counterexamples help a lot in understanding. Markus
> The reason is that sum only works on integer lists, whereas the given > type for fun requires that the first argument be a function that works > on lists of any type, such as length. > If sum were allowed as argument to fun, then we would also have to be > allowed to say: > > fun sum [True, False] [1,2] > > which clearly makes no sense. > > That Hugs refuses to report the type of fun has to with the fact that > such (rank-2) types cannot be inferred. GHC generally has > better support > for higher-ranked types (no general inference, of course). > > Hope that helped, > Janis. > > -- > Janis Voigtlaender > http://wwwtcs.inf.tu-dresden.de/~voigt/ > mailto:[EMAIL PROTECTED] > _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
