[GHC] #10056: Inconsistent precedence of ~

[GHC]

#10056: Inconsistent precedence of ~
-------------------------------------+-------------------------------------
        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                             |
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by simonpj):

 Can someone just summarise why we can't treat `(~)`, from a parsing point
 of view, as just an ordinary type operator with a specific fixity?  With
 no special treatment in the parser?   Why doe we need a "post-parsing
 pass" for `(~)`?

 And if it's just an ordinary operator, why does it even need to be built-
 in syntax?

 Maybe this all explained above, but a standalone summary would help make
 sure this ticket is well focused.  Thanks!

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10056#comment:39>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler