@sig(H/ ("a"/ H >> "x" >> ("a", "y")) >> "a" >> ["x"] >> ("a", ["y"]))
def mapAccumL(xs):
    """
    mapAccumL :: (a -> x -> (a, y)) -> a -> [x] -> (a, [y])

    The mapAccumL function behaves like a combination of map and foldl; it
    applies a function to each element of a list, passing an accumulating
    parameter from left to right, and returning a final value of this
    accumulator together with the new list.
    """
    raise NotImplementedError()
dataset/ETHPy150Open billpmurphy/hask/hask/Data/List.py/mapAccumL/swapped operands of `/`