[GHC] #12820: Regression around pattern synonyms and higher-rank types

[GHC]

#12820: Regression around pattern synonyms and higher-rank types
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        Reporter:  goldfire          |                Owner:  goldfire
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.1
  checker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by goldfire):

 * owner:   => goldfire


Comment:

 Maybe this ''is'' what kept me awake last night. Or maybe it was my cat
 who felt the need to lovingly stroke my face roughly hourly. Until she was
 banished to the kitchen.

 No, I'm not overly bothered by this. But it is subtly wrong, according to
 any bidirectional accounting of a type system that accommodates view
 patterns and has principal types.

 I'll put this in my queue. At the bottom. :)

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12820#comment:4>
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