[GHC] #12879: (xs -> xs) wrongly suggests TypeApplications

[GHC]

#12879: (xs -> xs) wrongly suggests TypeApplications
-------------------------------------+-------------------------------------
        Reporter:  Iceland_jack      |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Poor/confusing    |  Unknown/Multiple
  error message                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2877
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Ben Gamari <ben@…>):

 In [changeset:"b28ca38e6e1d75f3c10cc593cdd2ac80ec29690f/ghc" b28ca38/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="b28ca38e6e1d75f3c10cc593cdd2ac80ec29690f"
 Don't suggest enabling TypeApplications when it's already enabled

 Previously when encountering EAsPat in an expression context,
 TypeApplications was suggested even when already enabled. This patch
 replaces the suggestion with more appropriate message.

 Test Plan: validate

 Reviewers: austin, bgamari, mpickering, goldfire, simonpj

 Reviewed By: mpickering, goldfire, simonpj

 Subscribers: simonpj, goldfire, mpickering, thomie

 Differential Revision: https://phabricator.haskell.org/D2877

 GHC Trac Issues: #12879
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12879#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler