def test_monoid_law_right_identity(m):
# a + mempty = a
assert tc.mappend(m, tc.mempty(m)) == m
def test_Just_add_monoid_empty():
obj = object()
value = Just(obj)
assert value + mempty(value) == value
def test_monoid_law_left_identity(m):
# mempty + a = a
assert tc.mappend(tc.mempty(m), m) == m
def test_monoid_law_right_identity(monoids):
# a + mempty = a
monoid = monoids[0]
assert tc.mappend(monoid, tc.mempty(monoid)) == monoid
def test_monoid_law_left_identity(monoids):
# mempty + a = a
monoid = monoids[0]
assert tc.mappend(tc.mempty(monoid), monoid) == monoid
def test_monoid_law_left_identity(monoids):
# mempty + a = a
monoid = monoids[0]
assert tc.mappend(tc.mempty(monoid), monoid) == monoid
def test_monoid_law_right_identity(monoids):
# a + mempty = a
monoid = monoids[0]
assert tc.mappend(monoid, tc.mempty(monoid)) == monoid