[GHC] #8963: GeneralizedNewtypeDeriving unusable on associated types

[GHC]

#8963: GeneralizedNewtypeDeriving unusable on associated types
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        Reporter:  mojojojo          |            Owner:
            Type:  bug               |           Status:  closed
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.6.3
      Resolution:  fixed             |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
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Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"848f595266268f578480ceb4ab1ce4938611c97e/ghc"]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="848f595266268f578480ceb4ab1ce4938611c97e"
 Allow a longer demand signature than arity

 See Note [Demand analysis for trivial right-hand sides] in DmdAnal.
 This allows a function with arity 2 to have a DmdSig with 3 args;
 which in turn had a knock-on effect, which showed up in the test for
 Trac #8963.

 In fact it seems entirely reasonable, so this patch removes the
 WARN and CoreLint checks that were complaining.
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8963#comment:3>
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