[GHC] #11524: Something is amiss with quantification in pattern synonym type signatures

[GHC]

#11524: Something is amiss with quantification in pattern synonym type signatures
-------------------------------------+-------------------------------------
        Reporter:  bgamari           |                Owner:
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.0.1
       Component:  Compiler (Type    |              Version:  8.0.1-rc1
  checker)                           |             Keywords:
      Resolution:                    |  PatternSynonyms
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D1879,
       Wiki Page:                    |  Phab:D1896
-------------------------------------+-------------------------------------

Comment (by Ben Gamari <ben@…>):

 In [changeset:"3801262e89957a0fceeec0c5683045cf327aac64/ghc"
 3801262e/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="3801262e89957a0fceeec0c5683045cf327aac64"
 Fix printing of an `IfacePatSyn`

 Now the existentially quantified type variables are printed
 at the correct location when printing a pattern synonym type
 from an `IfacePatSyn`. The function `pprIfaceContextMaybe`
 has been removed as it is no longer needed.

 Fixes #11524.

 Reviewers: austin, goldfire, thomie, bgamari, mpickering

 Reviewed By: bgamari

 Differential Revision: https://phabricator.haskell.org/D1958

 GHC Trac Issues: #11524
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11524#comment:11>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler