[GHC] #16082: Sort out treatment of underscores in types

[GHC]

#16082: Sort out treatment of underscores in types
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        Reporter:  goldfire          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.7
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by goldfire):

 One thought here: we could conceivably treat anonymous wildcards `_` and
 named wildcards `_w` differently. This would give users some control over
 the feature.

 Indeed, this is what will be merged with #12045, where we will warn about
 `Proxy @_k Int` telling the user that `_k` was unified with `Type` but be
 silent about `Proxy @_ Int`.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16082#comment:1>
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