[GHC] #8177: Roles for type families

[GHC]

#8177: Roles for type families
-------------------------------------+------------------------------------
        Reporter:  simonpj           |            Owner:  goldfire
            Type:  bug               |           Status:  new
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.6.3
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
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Comment (by goldfire):

 But that's the annotation for the instance

 {{{
 data instance T [a]
 }}}

 If we had an instance

 {{{
 data instance T (Int, Maybe a)
 }}}

 the role annotation would be

 {{{
 type role instance T (Int, Maybe representational)
 }}}

 for example. (Though, that particular annotation would be a no-op, as
 `representational` would be inferred.) I don't believe I'm conflating list
 syntax here...

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8177#comment:8>
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