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

[GHC]

#13735: RankNTypes don't work with PatternSynonyms
-------------------------------------+-------------------------------------
        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             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 simonpj):

 Re comment:1, it's unsurprising that
 {{{
 llam f = L (Lam f)
 }}}
 with no type signature, does not work.  Because `f` needs to have a
 polytype, and it won't without a type sig.

 But re the original Description, I agree that the bidirectional definition
 should go through. I'll take a look.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13735#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler