[GHC] #15050: ScopedTypeVariables could allow more programs

[GHC]

#15050: ScopedTypeVariables could allow more programs
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        Reporter:  nomeata           |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.4.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by goldfire):

 I think comment:3 is a red herring. You're right that GHC rejects that
 type family, but that has more to do with the way that GHC does type-level
 GADT pattern matching than anything with scoped type variables. You could
 argue that it's suboptimal (though it matches what Agda does, I believe),
 but it's a separate matter from this ticket, I believe.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15050#comment:4>
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