[GHC] #10056: Inconsistent precedence of ~

[GHC]

#10056: Inconsistent precedence of ~
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        Reporter:  crockeea          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.8.1
       Component:  Compiler          |              Version:  7.8.4
  (Parser)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #10059, #10431,   |  Differential Rev(s):  Phab:D4876
  #14316, #15457                     |
       Wiki Page:                    |
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Changes (by RyanGlScott):

 * related:  #10059, #10431, #14316 => #10059, #10431, #14316, #15457


Comment:

 Replying to [comment:41 simonpj]:
 > So is `(~)` (in types) handled uniformly with `(!)`?  It seems not.
 Perhaps that's because we don't want to give up `(~)` as an infix
 operator, but we are willing to give up `(!)`?

 Ugh, that's a very good point. We //should// be able to use `!` as a type
 operator, but because of this lack of uniformity, we can't. We should fix
 this.

 > Anyway, it'd be good to summarise how the moving parts fit together, in
 a Note.  There are some e.g. `Note [Parsing ~]`, but they are too brief to
 do justice to the question.

 Indeed, `Note [Parsing ~]` could stand to be a bit longer.

 I've opened #15457 for both of these issues.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10056#comment:42>
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