[GHC] #2530: deriving Show adds extra parens for constructor with record syntax

[GHC]

#2530: deriving Show adds extra parens for constructor with record syntax
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        Reporter:  spl               |                Owner:  bgamari
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.0.1
       Component:  Compiler          |              Version:  6.8.3
      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:D669
       Wiki Page:                    |
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Comment (by bgamari):

 I would be fine with retaining the old behavior, keeping the parens, for
 now. It's pretty widely believed that the binding of record syntax
 specified in the report was a mistake. Let's allow the Haskell Prime
 committee to discuss this matter before we commit to changing `Show`.
 While it's almost certainly not practical to change the binding of record
 syntax, the next report could specify a more lax semantics for `Show`.

 To be clear, I'm merely requesting that the committee add this matter to
 their list of matters to address; their final decision is of course in
 their hands. If there is a good chance that the committee will consider
 such a change, then let's revert the commit in comment:25 for now and
 reconsider after the committee has made their decision.

 If it's unlikely that the next report will loosen `Show`, then we should
 decide now whether we want retain and document the old behavior as an
 infelicity of GHC's implementation, or whether we want to come into
 compliance with the Report. I'm slightly leaning towards the former for
 the sake of stability, although I'm happy to hear arguments in the other
 direction.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/2530#comment:36>
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