[GHC] #10270: inconsistent semantics of type class instance visibility outside recursive modules

[GHC]

#10270: inconsistent semantics of type class instance visibility outside recursive
modules
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        Reporter:  skilpat           |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Compiler          |                 Version:  7.10.1
      Resolution:                    |                Keywords:
Operating System:  MacOS X           |            Architecture:  x86_64
 Type of failure:  GHC rejects       |  (amd64)
  valid program                      |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:  #9562             |  Differential Revisions:
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Comment (by simonpj):

 I rather agree that the one-shot story is the right one.  And yes, the two
 should agree.

 Edward I recall that we had extensive discussion about how to arrange that
 the right instances are in scope.  We had a New Plan; but (a) I have
 forgotten the plan and (b) I'm not sure whether it was ever implemented.
 Can you remind me?

 Simon

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10270#comment:3>
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