[GHC] #4517: Add Data.Functor.Backwards to transformers

roconnor at theorem.ca roconnor at theorem.ca
Sat Nov 20 17:25:23 EST 2010

#4517: Add Data.Functor.Backwards to transformers
    Reporter:  r6                |       Owner:
        Type:  proposal          |      Status:  new
    Priority:  normal            |   Component:  libraries (other)
     Version:  7.0.1             |    Keywords:  backwards
    Testcase:                    |   Blockedby:
          Os:  Unknown/Multiple  |    Blocking:
Architecture:  Unknown/Multiple  |     Failure:  None/Unknown
Data.Functor.Backwards is a wrapper for functors that allow Foldable,
Traversable, and Applicative functors to be operated backwards.  It is
similar to Dual for Monoids.  The Applicative instance runs effects in
reversed order.  The Foldable instance folds from right to left, The
Traversable instance traverses from right to left.

Russell O'Connor                                      <http://r6.ca/>
``All talk about `theft,''' the general counsel of the American Graphophone
Company wrote, ``is the merest claptrap, for there exists no property in
ideas musical, literary or artistic, except as defined by statute.''

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