@sig(H/ (H/ "a" >> t(Maybe, "b")) >> ["a"] >> ["b"])
def mapMaybe(f, la):
    return L[(fromJust(b) for b in (f(a) for a in la) if isJust(b))]
mapMaybe :: (a -> Maybe b) -> [a] -> [b]
dataset/ETHPy150Open billpmurphy/hask/hask/Data/Maybe.py/mapMaybe