def test_compose_mapping_and_filter(self):
tdx = compose(
tdc.filtering(lambda x: x < 5),
tdc.mapping(lambda x: x * 2))
x = tdc.reduce(tdx(operator.mul),
range(1, 10), 1)
self.assertEqual(
x,
tdc.reduce(operator.mul,
(i * 2 for i in range(1, 10) if i < 5),
1))
def test_reuse_single_taking_instance(self):
take_5 = tdc.taking(5)
tdx = compose(
take_5,
tdc.mapping(lambda x: x * 2),
take_5)
x = tdc.reduce(tdx(append), range(100), [])
y = itertools.islice(
(x * 2 for x in itertools.islice(range(100), 5)), 5)
self.assertEqual(x, list(y))
def test_compose_three_transducers(self):
tdx = compose(
tdc.mapping(lambda x: x * 2),
tdc.mapping(lambda x: x * x),
tdc.filtering(lambda x: x % 2 == 0))
x = tdc.reduce(tdx(operator.add),
range(100), 0)
self.assertEqual(
x,
sum(filter(lambda x: x % 2 == 0,
(x * x
for x in (y * 2
for y in range(100))))))
def test_taking_while_does_not_consume_all_input(self):
lt_10 = tdc.taking_while(lambda x: x < 10)
input_data = (i for i in range(100))
tdc.reduce(lt_10(operator.add), input_data, 0)
self.assertEqual(len(list(input_data)), 89)
def test_taking_does_not_consume_all_input(self):
take_5 = tdc.taking(5)
input_data = (i for i in range(100))
tdc.reduce(take_5(operator.add), input_data, 0)
self.assertEqual(len(list(input_data)), 95)
def test_taking_while(self):
t = tdc.taking_while(lambda x: x < 10)
x = tdc.reduce(t(operator.add), range(100), 0)
self.assertEqual(x, sum(range(10)))
def test_taking(self):
t = tdc.taking(10)
x = tdc.reduce(t(operator.add), range(100), 0)
self.assertEqual(x, sum(range(10)))
def test_mapcatting(self):
m = tdc.mapcatting(reversed)
x = tdc.reduce(m(tdc.conj), ((3, 2, 1, 0), (6, 5, 4)), [])
self.assertListEqual(x, list(range(7)))
def test_filtering(self):
f = tdc.filtering(lambda x: x < 10)
x = tdc.reduce(f(operator.add), range(100), 0)
self.assertEqual(x, sum(range(10)))
def test_mapping(self):
tdx = tdc.mapping(lambda x: x * 2)
x = tdc.reduce(tdx(operator.add), range(10), 0)
self.assertEqual(x, sum(x * 2 for x in range(10)))
