A Haskell foldl that slides a "window" over the list

winFold.hs

-- f now takes a sliding sublist of values, rather than each value
-- n is the window size
winFold :: ([a] -> b -> b) -> b -> [a] -> Int -> b
winFold f acc n [] = acc
winFold f acc n xs = winFold f (f (take n xs) acc) (tail xs) n