| Simon Peyton-Jones wrote: | > I'm very interested to know whether you like it or hate it. | > In the latter case, I'd also like to know whether you also | > have programs that will be broken by the change. | | I don't use GADTs yet and I assume this change will not (seriously) | break our code, but let me/us know which compiler we should use for testing.

I've installed now ghc-6.5.20060201 and I get quite a few errors of the form: A pattern type signature cannot bind scoped type variables `s' unless the pattern has a rigid type context (and these are not always easy to fix in unknown non-haskell98 code by adding a "forall" and/or omitting the pattern type signatures) Christian You may try to translate the attached sources by: ghc --make -cpp -fallow-undecidable-instances -fglasgow-exts VariableList.hs (and tell me how I should fix this)