prefixes :: Foldable t => t a -> [[a]]
--prefixes xs = foldr(\x acc -> [[]] ++ map (x:) acc) [[]] xs
--prefixes = foldr(\x acc -> [[]] ++ map (x:) acc) [[]]
--prefixes = foldr(\x -> \acc -> [[]] ++ map (x:) acc) [[]]
--prefixes = foldr(\x -> \acc ->(++) [[]]  (map (x:) acc)) [[]]
--prefixes = foldr(\x -> \acc ->((++) [[]])  (map (x:) acc)) [[]]
--prefixes = foldr(\x -> ((++) [[]]) . \acc -> (map (x:) acc)) [[]]
--prefixes = foldr(\x -> ((++) [[]]) . \acc -> (map (x:)) acc) [[]]
--prefixes = foldr(\x -> ((++) [[]]) . (map (x:)) . \acc ->  acc) [[]]
--prefixes = foldr(\x -> ((++) [[]]) . (map (x:)) . id) [[]]
--prefixes = foldr(\x -> (((++) [[]]) .) (map (x:) . id)) [[]]
--prefixes = foldr(((++) [[]] .) . \x ->(flip (.) id) (map (x:)) ) [[]]
--prefixes = foldr (((++) [[]] .) . (flip (.) id) . \x ->  (map (x:))) [[]]
--prefixes = foldr (((++) [[]] .) . flip (.) id . \x -> map ((:)x)) [[]]


prefixes = foldr (((++) [[]] .) . flip (.) id . map . (:)) [[]]