[GHC] #13735: RankNTypes don't work with PatternSynonyms

[GHC]

#13735: RankNTypes don't work with PatternSynonyms
-------------------------------------+-------------------------------------
        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:  invalid           |             Keywords:
                                     |  PatternSynonyms
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Iceland_jack):

 `f (B endo) = A (appEndo endo)` works while this doesn't

 {{{#!hs
 f :: B -> A
 f (B (appEndo -> f)) = A f
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13735#comment:12>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler