def flat_map(self) -> None:
s = MaybeState.pure(1)
def f(a: int) -> None:
return MaybeState.inspect(lambda s: len(s) + a)
s1 = s.flat_map(f)
return s1.run('str').should.equal(Just(('str', 4)))
def pure(self) -> None:
MaybeState.pure(1).run('state').should.equal(Just(('state', 1)))
def transform_f(self) -> None:
MaybeState.pure(7).transform_f(
EitherState,
lambda m: m.to_either('none')).run_a(None).should.equal(Right(7))
def modify_f(self) -> None:
MaybeState.modify_f(
(lambda s: Just(s + ' updated'))).run_s('state').should.equal(
Just('state updated'))
def f(a: int) -> None:
return MaybeState.inspect(lambda s: len(s) + a)