[GHC] #14191: Implement Semigroup as a superclass of Monoid Proposal (Phase 2)

[GHC]

#14191: Implement Semigroup as a superclass of Monoid Proposal (Phase 2)
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        Reporter:  hvr               |                Owner:  hvr
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:  8.4.1
       Component:  libraries/base    |              Version:  8.2.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #10365            |  Differential Rev(s):  phab:D3927
       Wiki Page:                    |
  prime:Libraries/Proposals/SemigroupMonoid|
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Comment (by RyanGlScott):

 The subtext of that question is that there are eventual plans to change
 the `Monoid` instance for `Maybe` to be `instance Semigroup a => Monoid
 (Maybe a)` (i.e., to remove
 [http://git.haskell.org/ghc.git/blob/838a10fcad9168895b49b4709056b549f2888860:/libraries/base/GHC/Base.hs#l413
 this piece] of documentation). When that happens, there really will be no
 substantial difference between `Option` and `Maybe`.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14191#comment:7>
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