[GHC] #10189: explicit promotions of prefix data constructors can't be parsed naturally

[GHC]

#10189: explicit promotions of prefix data constructors can't be parsed naturally
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        Reporter:  Kinokkory         |                   Owner:  Kinokkory
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:  7.12.1
       Component:  Compiler          |                 Version:  7.8.4
  (Parser)                           |                Keywords:
      Resolution:                    |            Architecture:
Operating System:  Unknown/Multiple  |  Unknown/Multiple
 Type of failure:  GHC rejects       |               Test Case:
  valid program                      |                Blocking:
      Blocked By:                    |  Differential Revisions:
 Related Tickets:  #10188            |
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Comment (by simonpj):

 Ah well making `'` scope over a ''term'', not just a ''name'', is a whole
 new unexplored ball of wax.

 I'd rather make what we have fit together nicely, otherwise we pay now for
 a distant and uncertain future benefit.  We can jump future bridges when
 we come to them.

 I don't think we have enough legacy code to make wibblification on
 existing packages into a serious problem.  I suppose we could allow both
 forms for a while, but emit deprecation messages for the old one.  But I
 don't think that even that is worth the trouble.

 Let's just make the change:
  * `(':)`, not `'(:)`
  * {{{`'Bar`}}}, not {{{'`Bar`}}}.

 Can someone do this?

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10189#comment:7>
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