[GHC] #15941: Pretty-printing of invisible arguments to (->)

[GHC]

#15941: Pretty-printing of invisible arguments to (->)
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        Reporter:  monoidal          |                Owner:  RyanGlScott
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:  8.8.1
       Component:  Compiler          |              Version:  8.6.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D5375
       Wiki Page:                    |
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Comment (by Ryan Scott <ryan.gl.scott@…>):

 In [changeset:"984b75de7082689ebcc6e9d17b37f2c9b3702f71/ghc"
 984b75de/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="984b75de7082689ebcc6e9d17b37f2c9b3702f71"
 Fix #15941 by only special-casing visible infix applications

 Summary:
 The iface pretty-printer had a special case for an
 application of an infix type constructor to two arguments. But this
 didn't take the visibilities of the arguments into account, which
 could lead to strange output like `@{LiftedRep} -> @{LiftedRep}` when
 `-fprint-explicit-kinds` was enabled (#15941). The fix is relatively
 straightforward: simply plumb through the visibilities of each
 argument, and only trigger the special case for infix applications
 if both arguments are visible (i.e., required).

 Test Plan: make test TEST=T15941

 Reviewers: goldfire, bgamari, monoidal

 Reviewed By: goldfire, monoidal

 Subscribers: simonpj, rwbarton, carter

 GHC Trac Issues: #15941

 Differential Revision: https://phabricator.haskell.org/D5375
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15941#comment:4>
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