You will have to give both the errors and the source code... I have done quite a bit with classes and GHC's constraint inferance is pretty good.
The chances are you really do need to add some extra constraints... (by the way if you are working with heterogeneous collections, you may be interested in out paper, http://www.cwi.nl/~ralf/HList ) Keean. _______________________________________________ Glasgow-haskell-bugs mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
