Daniel Fischer wrote: > {-# LANGUAGE MultiParamTypeClasses #-} > {-# LANGUAGE FunctionalDependencies #-} > {- # LANGUAGE FlexibleInstances # -} > module Leandro where > > data Abb a b = Branch a b (Abb a b) (Abb a b) | Leaf > > data ListAssoc a b = Node a b (ListAssoc a b) | Empty > > class Container c a b |c -> a, c -> b where > [...] > > instance (Ord a) => Container (Abb a b) a b where > [...] > > Note: The FlexibleInstances Language pragma is required by GHC 6.8.1 and > 6.8.2, but not by GHC 6.6.1 or hugs, I think that's a bug in 6.8.*
If it's a bug then it is probably in 6.6.1 too, it just gets hidden by the fact that in 6.6.1 the -fglasgow-exts extensions cannot be activated separately. If you enable one of them, you get them all. Cheers Ben _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe