Discussion on: Daily Challenge #72 - Matrix Shift

shift :: Int -> [String] -> [String]
shift n m =
  foldr unflatten [""] shifted
  where
    columns  = length $ head m
    flat_m   = concat m
    split_at = (length flat_m) - n
    shifted  = (drop split_at flat_m) ++ (take split_at flat_m)
    unflatten :: Char -> [String] -> [String]
    unflatten y (x:xs)
      | length x == columns = [y] : x : xs
      | otherwise           = ([y] ++ x) : xs

-- In haskell strings are lists of chars, so "abcd" is the same as ['a','b','c','d'] but shorter to type.
shift 1 [ "abcd", "1234", "code", "blah" ]
-- [ "habc", "d123", "4cod", "ebla" ]