John Tromp wrote: > >>instance (Bar a) => Foo a > I have tried to write code myself like in the last line, > stating that any instance of one class should also be > an instance of another class. But Hugs would complain about > it.
You're right. Hugs needs to be told that the code is in an extended Haskell, with popular extensions. Therefore, Hugs has to invoked as "hugs -98". It seems -98 flag cannot be changed once the Hugs is running. Incidentally, the previously posted code included rank-2 types -- which are flagrantly not in Haskell98. Therefore, without -98 flag, Hugs will have a lot to complain about. _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
