id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
33	Unboxing problems in example from Stack Overflow	Ben Lippmeier		"
{{{
import Data.Array.Repa

arr :: Array U DIM2 Int
arr = fromListUnboxed (Z :. 5 :. 5) [1..25]

combined :: Array U DIM2 Int
combined 
  = computeP $ traverse arr (\_ -> Z :. 4 :. 4 :: DIM2) 
  $ \f (Z :. x :. y) -> sumAllS $ extract f (x,y) (2,2)

extract :: (DIM2 -> Int) -> (Int,Int) -> (Int,Int) -> Array D DIM2 Int
extract lookup (x0,y0) (width,height) 
  = fromFunction bounds 
  $ \sh -> offset lookup sh
    where 
    bounds = Z :. width :. height
    offset :: (DIM2 -> Int) -> DIM2 -> Int
    offset f (Z :. x :. y) = f (Z :. x + x0 :. y + y0)

main = print combined
}}}"	defect	closed	normal	3.2.0	library	3.0.0	fixed