[GHC] #10839: Consistent pretty-printing of type families

[GHC]

#10839: Consistent pretty-printing of type families
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        Reporter:  jstolarek         |                Owner:  msosn
            Type:  task              |               Status:  new
        Priority:  lowest            |            Milestone:
       Component:  Compiler          |              Version:  7.11
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D1441
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"c61759d5917996a10b06a286eb5b776e4069e35c/ghc" c61759d/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="c61759d5917996a10b06a286eb5b776e4069e35c"
 Fix inconsistent pretty-printing of type families

 After the changes, the three functions used to print type families
 were identical, so they are refactored into one.

 Original RHSs of data instance declarations are recreated and
 printed in user error messages.

 RHSs containing representation TyCons are printed in the
 Coercion Axioms section in a typechecker dump.

 Add vbar to the list of SDocs exported by Outputable.
 Replace all text "|" docs with it.

 Fixes #10839

 Reviewers: goldfire, jstolarek, austin, bgamari

 Reviewed By: jstolarek

 Subscribers: jstolarek, thomie

 Differential Revision: https://phabricator.haskell.org/D1441

 GHC Trac Issues: #10839
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10839#comment:4>
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