[GHC] #13573: Add Foldable1 to base

[GHC]

#13573: Add Foldable1 to base
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        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      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):
       Wiki Page:                    |
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Comment (by chshersh):

 Alternative naming option would be `NonEmptyFoldable` or `FoldableNE` or
 something similar. But this is either long or non-uniform. `Foldable1` is
 good enough. And we probably won't need type classes like `Eq1` and
 `Show1` in future since we have `QuantifiedConstraints` landed in GHC. In
 some moment of time they can be deprecated and removed. So we only need to
 prepare for StackOverflow and Reddit questions like ''Why `Eq1` and
 `Show1` are different from `Eq` and `Show` in not the same way as
 `Foldable1` from `Foldable`?''. But I guess this is manageable.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13573#comment:16>
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