Neil Mitchell wrote: > I'm looking for a type class which checks whether two types are the > same or not.
This problem is more complex than appears. It has been solved, however. IncoherentInstances are not required, as IncoherentInstances are generally unsafe. For the full discussion of various solutions, please see Section 9 and Appendix D of the HList paper: http://homepages.cwi.nl/~ralf/HList/paper.pdf The HList code is available http://darcs.haskell.org/HList/ It includes the examples from the paper. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe