[GHC] #9763: Implement Foldable methods for Array directly

[GHC]

#9763: Implement Foldable methods for Array directly
-------------------------------------+-------------------------------------
       Reporter:  dfeuer             |                   Owner:  dfeuer
           Type:  task               |                  Status:  new
       Priority:  normal             |               Milestone:  7.10.1
      Component:  Compiler           |                 Version:  7.9
       Keywords:                     |        Operating System:
   Architecture:  Unknown/Multiple   |  Unknown/Multiple
     Difficulty:  Unknown            |         Type of failure:
     Blocked By:                     |  None/Unknown
Related Tickets:                     |               Test Case:
                                     |                Blocking:
                                     |  Differential Revisions:
-------------------------------------+-------------------------------------
 Currently, they're implemented via conversion to lists. This works out
 sanely for `foldr` and `foldr1`, after some transformations, but it's
 rather less sane for left folds. Left folds end up "twisted" like their
 list counterparts, giving potentially surprising performance
 characteristics. For `Array`, left and right folds can reasonably be
 expected to be symmetrical.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9763>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler