[GHC] #15209: ~# is always in scope with TypeOperators

[GHC]

#15209: ~# is always in scope with TypeOperators
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        Reporter:  dfeuer            |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.5
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC accepts       |  Unknown/Multiple
  invalid program                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4763
       Wiki Page:                    |
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Changes (by RyanGlScott):

 * status:  closed => new
 * resolution:  fixed =>


Comment:

 Unfortunately, it turns out that removing the `'(' '~#' ')'` production
 from the parser is //not// enough, as the original program in this ticket
 can still be written even after this most recent patch.

 In order to truly cut off access to `(~#)` from users, we need to find
 some way to avoid exporting `(~#)` from `GHC.Prim`. We should probably
 also do the same for `(~R#)` and `(~P#)`, because while you can't actually
 use those in the source syntax, you //can// view them with `:browse` (as
 discovered in #12023).

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15209#comment:9>
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