[GHC] #7964: GADTs in Haskell98 style

[GHC]

#7964: GADTs in Haskell98 style
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Reporter:  wvv               |          Owner:                         
    Type:  feature request   |         Status:  new                    
Priority:  normal            |      Component:  Compiler (Type checker)
 Version:  7.6.3             |       Keywords:                         
      Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple       
 Failure:  Other             |      Blockedby:                         
Blocking:                    |        Related:                         
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 it would be nice if it is possible to write GADTs in Haskell98 style, like
 this:


 {{{
 data Expr a = I Int   :: Expr Int
             | B Bool  :: Expr Bool
             | Add (Expr Int) (Expr Int)  :: Expr Int
             | Mul (Expr Int) (Expr Int)  :: Expr Int
             | Eq  (Expr Int) (Expr Int)  :: Expr Bool
             | Magic  (Expr a) (Expr a)
 }}}

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Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7964>
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