GADT Type Checking GHC 6.10 versus older GHC

[Dominic Steinitz]

Simon Peyton-Jones wrote:
> | > I also feel that the type errors given when working with existential
> | > types, especially GADTs with existentials, are confusing.  I think
> |
> | I am using existential types to test GADT code. See
> | http://www.haskell.org/haskellwiki/QuickCheck_/_GADT which no longer
> | works with 6.10.1.
> 
> Really?  I've just compiled that entire page with 6.10.1, and it was fine, except that I had to add a type signature for prettyRep.  No problems there.
> 
> Simon
> 
> 
Sorry I inadvertently used an old copy of ghc.

Dominic.