[GHC] #13177: Give Data.Functor.* its lifted unit and void

[GHC]

#13177: Give Data.Functor.* its lifted unit and void
-------------------------------------+-------------------------------------
           Reporter:  Iceland_jack   |             Owner:
               Type:  feature        |            Status:  new
  request                            |
           Priority:  normal         |         Milestone:
          Component:                 |           Version:  8.0.1
  libraries/base                     |
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 `GHC.Generics` has

 {{{#!hs
 data U1 a = U1
 data V1 a
 }}}

 They are simple but why are they not present in the `Data.Functor`
 hierarchy along with functions like (from
 [https://hackage.haskell.org/package/one-liner-0.7/docs/src/Generics-
 OneLiner-Internal.html one-liner])

 {{{#!hs
 absurd :: V1 a -> b
 absurd = \case
 }}}

 Packages like [https://hackage.haskell.org/package/linear linear] provide
 basically the same lifted functors

 {{{#!hs
 data    V0 a = V0
 newtype V1 a = V1 a
 }}}

 if they or those from `GHC.Generics` should be preferred it could be added
 to the documentation.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13177>
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