def test_applicative_eq_evaluated():
lazy1 = Lazy(fn)
lazy2 = Lazy(fn)
lazy1.get()
assert lazy1 != lazy2
lazy2.get()
assert lazy1 == lazy2
def test_applicative_eq_value():
lazy1 = Lazy(random)
lazy2 = Lazy(random)
lazy1.get()
lazy2.get()
assert lazy1 == lazy1
assert lazy2 == lazy2
assert lazy1 != lazy2
def test_lazy_monad_laws(integer):
def get_fn(lazy):
if isinstance(lazy.constructor_fn, types.FunctionType):
return lazy.get()
return lazy.constructor_fn
MonadLawTester(monad=Lazy.of,
value=integer,
mapper1=lambda value: Lazy(value + 1),
mapper2=lambda value: Lazy(value + 2),
get_fn=get_fn).test(run_associativity_law_test=False,
run_right_law_test=False)
def to_lazy(self):
"""
Transform Maybe to Try.
:returns: Lazy monad with function returning previous value in other case Left with None
:rtype: Lazy[Function() -> (A | None)]
"""
from pymonet.lazy import Lazy
if self.is_nothing:
return Lazy(lambda: None)
return Lazy(lambda: self.value)
def test_applicative_should_call_stored_function_during_fold_method_call(
lazy_spy):
applicative = Lazy(lazy_spy.fn)
assert lazy_spy.fn.call_count == 0
assert applicative.get() == 42
assert lazy_spy.fn.call_count == 1
def test_applicative_should_not_call_mapper_until_call_get(lazy_spy):
applicative = Lazy(lazy_spy.fn).map(lazy_spy.mapper)
assert lazy_spy.fn.call_count == 0
assert lazy_spy.mapper.call_count == 0
assert applicative.get() == 43
assert lazy_spy.fn.call_count == 1
assert lazy_spy.mapper.call_count == 1
def test_applicative_should_call_memoize_saved_value(lazy_spy):
lazy = Lazy(lazy_spy.fn)
value1 = lazy.get()
assert lazy_spy.fn.call_count == 1
value2 = lazy.get()
assert lazy_spy.fn.call_count == 1
assert value1 is value2
def to_lazy(self):
"""
Transform Either to Try.
:returns: Lazy monad with function returning previous value
:rtype: Lazy[Function() -> A]
"""
from pymonet.lazy import Lazy
return Lazy(lambda: self.value)
def to_lazy(self):
"""
Transform Box into Lazy with returning value function.
:returns: not folded Lazy monad with function returning previous value
:rtype: Lazy[Function(() -> A)]
"""
from pymonet.lazy import Lazy
return Lazy(lambda: self.value)
def test_applicative_eq():
assert Lazy(fn) != {}
assert Lazy(fn) != []
assert Lazy(fn) != Lazy(fn1)
assert Lazy(fn) == Lazy(fn)
def test_applicative_should_not_call_binder_until_call_get(lazy_spy):
lazy = Lazy(lazy_spy.fn)
assert lazy_spy.fn.call_count == 0
assert lazy_spy.binder.call_count == 0
lazy = lazy.bind(lazy_spy.binder)
assert lazy_spy.fn.call_count == 0
assert lazy_spy.binder.call_count == 0
result = lazy.get()
assert lazy_spy.fn.call_count == 1
assert lazy_spy.binder.call_count == 1
assert result == 43
def binder(self, value):
return Lazy(value + 1)
def test_lazy_functor_law(integer):
FunctorLawTester(functor=Lazy(lambda: integer),
mapper1=lambda value: value + 1,
mapper2=lambda value: value + 2,
get_fn=lambda lazy: lazy.get()).test()
def test_lazy_applicative(integer):
assert Lazy(identity).ap(
Lazy(lambda: integer)).get() == Lazy(lambda: integer).get()
assert Lazy(increase).ap(Lazy(lambda: integer)).get() == increase(integer)
def test_transform_to_validation_should_validation(integer):
assert Lazy(lambda: integer).to_validation() == Validation.success(integer)