def eff_flat_io_empty(self):
t = IO.now(List(Right(Empty())))
target = List(Right(Empty()))
res = (t.effs(
4, List, Either, Maybe,
Either).flat_map(lambda x: IO.now(List(Right(Just(Right(1)))))))
res.value.run().should.equal(target)
def eff_flat_io(self):
a, b = self._r
t = IO.now(List(Right(Just(Right(a)))))
target = List(Right(Just(Right(a + b))))
res = (t.effs(
4, List, Either, Maybe,
Either).flat_map(lambda x: IO.now(List(Right(Just(Right(x + b))))))
)
res.value.run().should.equal(target)
def flat_map_twice(self) -> None:
v = 13
w = 29
x = 17
t = (
IO.now(v)
.flat_map(L(IO.now)(_ + w))
.flat_map(L(IO.now)(_ + x))
)
t.attempt.should.contain(v + w + x)
def eff_map_io(self):
a, b = self._r
t = IO.now(List(Just(a), Just(b), Empty()))
target = List(Just(a + b), Just(b + b), Empty())
res = t.effs(2).map(_ + b)
res.value.run().should.equal(target)
def pure(self, a: A) -> IO[A]:
return IO.now(a)
def and_then(self) -> None:
v = 7
f = lambda: v
t = IO.now(1).and_then(IO.delay(f))
t.attempt.should.contain(v)
def map(self) -> None:
v = 13
w = 29
t = IO.now(v).map(_ + w)
t.attempt.should.contain(v + w)
def sequence(self) -> None:
f = lambda: 3
t = List(IO.now(1), IO.now(2), IO.delay(f)).sequence(IO)
t.attempt.should.equal(Right(List(1, 2, 3)))
def now_flat_map(self) -> None:
t = IO.now(5) // IO.now
target = 'Suspend(Pure(5).flat_map(now))'
str(t).should.equal(target)
def flat_map_now(self) -> None:
v = 13
w = 29
t = IO.now(v).flat_map(L(IO.now)(_ + w))
t.attempt.should.contain(v + w)
def suspend(self) -> None:
v = 13
w = 29
f = lambda a: IO.now(a + v)
t = IO.suspend(f, w)
t.run().should.equal(v + w)
def now(self) -> None:
v = 5
t = IO.now(v)
t.attempt.should.contain(v)
def trampoline(self) -> None:
t = (List.range(1000).fold_left(IO.now(1))(lambda z, a: z.flat_map(IO.now, fs=Just('now'))))
t.attempt.should.contain(1)
def zip(self) -> None:
t = IO.now(1) & IO.now(2)
t.attempt.should.equal(Right((1, 2)))
def now_map(self) -> None:
t = IO.now(5) / (_ + 1)
target = 'Suspend(Pure(5).map(lambda a: (lambda b: a + b)(1)))'
str(t).should.equal(target)
str(t.step()).should.equal('Pure(6)')
def eff_flat_io_left(self):
a, b = self._r
t = IO.now(Left(Just(a)))
target = Left(Just(a))
res = t.effs(1, Either, Maybe) // (lambda x: IO.now(Right(Just(b))))
res.value.run().should.equal(target)
def now(self) -> None:
str(IO.now(5)).should.equal('Pure(5)')