[GHC] #1768: More flexible type signatures for data constructors

[GHC]

#1768: More flexible type signatures for data constructors
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    Reporter:  simonpj          |        Owner:         
        Type:  feature request  |       Status:  new    
    Priority:  low              |    Milestone:  _|_    
   Component:  Compiler         |      Version:  6.6.1  
    Severity:  normal           |   Resolution:         
    Keywords:                   |   Difficulty:  Unknown
          Os:  Unknown          |     Testcase:         
Architecture:  Unknown          |  
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Comment (by Isaac Dupree):

 A more limited generalization would be to allow the result type to be a
 type synonym:

 {{{
 type Foo a = T (Maybe a) [a]

 data T a b where
    C :: !Int -> Foo Int
    D { unD :: !Int } :: Foo Int
 }}}

 This is mostly relevant/useful when the GADT has more than one type
 argument.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1768#comment:1>
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