Does the "zipper" fall into this category?
http://haskell.org/wiki/wiki?TheZipper
The zipper is a type-indexed data type, not just a type-indexed function.
See:
R. Hinze, J. Jeuring and A Löh. Type-indexed data types. In Eerke A. Boiten and Bernhard Möller, editors, Proceedings of the 6th International Conference on Mathematics of Program Construction, LNCS 2386, pages 148 - 174, 2002, © Springer-Verlag.
-- Johan _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
