[GHC] #11623: Wrong error message for type family definition that is wrong in multiple ways

[GHC]

#11623: Wrong error message for type family definition that is wrong in multiple
ways
-------------------------------------+-------------------------------------
        Reporter:  rwbarton          |                Owner:  rdragon
            Type:  bug               |               Status:  merge
        Priority:  low               |            Milestone:  8.0.1
       Component:  Compiler (Type    |              Version:  8.1
  checker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Other             |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2089
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"46e8f199e4d3baffa306a40082fbc2fce67f779f/ghc"
 46e8f199/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="46e8f199e4d3baffa306a40082fbc2fce67f779f"
 Fix a closed type family error message

 Now we check whether a closed type family's equation is headed with
 the correct type before we kind-check the equation.

 Also, instead of "expected only no parameters" we now generate the
 message "expected no parameters".

 Fixes #11623.

 Reviewers: simonpj, austin, bgamari

 Reviewed By: simonpj, bgamari

 Subscribers: simonpj, goldfire, thomie

 Differential Revision: https://phabricator.haskell.org/D2089

 GHC Trac Issues: #11623
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11623#comment:5>
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