Proposal: Deprecate ExistentialQuantification

Simon Peyton-Jones simonpj at microsoft.com
Mon Jun 29 03:42:02 EDT 2009


| That's why one should really be allowed to group constructor's in a
| type's definition:
| 
|    data Colour :: * where
|      Red, Green, Blue :: Colour

Indeed.  GHC allows this now.  (HEAD only; will be in 6.12.)

Simon



More information about the Haskell-prime mailing list