module ArrayStuff where
import Data.Ix
import Data.Array.IArray

funcArray lohi f = listArray lohi $ map f $ range lohi

constArray lohi v = listArray lohi $ repeat v

transposeArray arr =
	let swap (x, y) = (y, x) in
	let (lo, hi) = bounds arr in
	ixmap (swap lo, swap hi) swap arr

array2DtoListOfLists arr =
	let ((xlo, ylo), (xhi, yhi)) = bounds arr in
	map (\x -> map (\y -> arr ! (x, y)) $ range (ylo, yhi)) $ range (xlo, xhi)

listOfListsToArray2D ll =
	listArray ((0, 0), (length ll - 1, length (head ll) - 1)) $ concat ll

-- Use instead of amap when the array implementation needs to change.
-- E.g., mapping an unboxed array to an array whose elements must be boxed.
amap2 f arr = funcArray (bounds arr) (\i -> f (arr ! i))

-- Like amap2 but the mapping function is also passed the index.
aixmap f arr = funcArray (bounds arr) (\i -> f i (arr ! i))