[GHC] #3497: Template Haskell support for GADTs

[GHC]

#3497: Template Haskell support for GADTs
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    Reporter:  simonpj           |        Owner:              
        Type:  feature request   |       Status:  new         
    Priority:  normal            |    Milestone:  6.14.1      
   Component:  Compiler          |      Version:  6.10.4      
    Keywords:                    |   Difficulty:  Unknown     
          Os:  Unknown/Multiple  |     Testcase:              
Architecture:  Unknown/Multiple  |      Failure:  None/Unknown
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Comment(by simonpj):

 A related question is that of reifying type-class instances.  Here there
 is a bit more design to do.  I suppose you might want to add a new method
 to `Quasi`, something like
 {{{
   qReifyInstances :: Pred -> m InstanceInfo
 }}}
 Here the idea is that to get all the instances matching, say `(C [a])`
 you'd give that predicate to `qReifyInstances` and it'd return all the
 matching instances.

 See http://www.mail-archive.com/haskell-cafe@haskell.org/msg13057.html for
 example.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3497#comment:4>
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