[GHC] #14289: Pretty-printing of derived multi-parameter classes omits necessary parentheses

[GHC]

#14289: Pretty-printing of derived multi-parameter classes omits necessary
parentheses
-------------------------------------+-------------------------------------
        Reporter:  RyanGlScott       |                Owner:  alanz
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.1
  (Parser)                           |
      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:D4056
       Wiki Page:                    |
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Comment (by Alan Zimmerman <alan.zimm@…>):

 In [changeset:"6869864eac211885edcd4b14425fd368069e4aba/ghc"
 6869864e/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="6869864eac211885edcd4b14425fd368069e4aba"
 Pretty-printing of derived multi-parameter classes omits parentheses

 Summary:
 Pretty printing a splice with an HsAppType in the deriving clause, such as

     $([d| data Foo a = Foo a deriving (C a) |])

 would omit the parens.

 Test Plan: ./validate

 Reviewers: RyanGlScott, austin, bgamari

 Subscribers: rwbarton, thomie

 GHC Trac Issues: #14289

 Differential Revision: https://phabricator.haskell.org/D4056
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14289#comment:3>
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