@sig(H/ (H/ "b" >> "a" >> "b") >> "b" >> ["a"] >> ["b"])
def scanl(f, z, xs):
    """
    scanl :: (b -> a -> b) -> b -> [a] -> [b]

    scanl is similar to foldl, but returns a list of successive reduced values
    from the left
    """
    raise NotImplementedError()
dataset/ETHPy150Open billpmurphy/hask/hask/Data/List.py/scanl/original