def test_deep_recursion():
def fact(n, result=1):
if n <= 1:
returnValue(result)
else:
noreturn(fact(n - 1, n * result))
yield
assert deferred_result(inlineCallbacks(fact)(1)) == 1
assert deferred_result(inlineCallbacks(fact)(10)) == safe_fact(10)
with recursion_limit(100):
with assert_not_raises(RuntimeError):
# +10 is actually too high here as we probably already have some stuff on the stack, but just to be sure
assert deferred_result(inlineCallbacks(fact)(110)) == safe_fact(110)
# ...and now let's prove that the same (tail call optimizable) algorithm without noreturn will eat up the stack
def normal_fact(n, result=1):
if n <= 1:
returnValue(result)
else:
return normal_fact(n - 1, n * result)
with recursion_limit(100):
with assert_raises(RuntimeError):
normal_fact(110)
def test_noreturn_with_regular_function():
after_noreturn_reached = [False]
@inlineCallbacks
def fn():
yield
noreturn(fn2())
after_noreturn_reached[0] = True
def fn2():
return "someretval"
retval = deferred_result(fn())
assert not after_noreturn_reached[0]
assert retval == "someretval"
def test_noreturn_of_other_inlineCallbacks_wrapped_callable():
after_noreturn_reached = [False]
@inlineCallbacks
def fn():
yield
noreturn(fn2())
after_noreturn_reached[0] = True
fn2_called = [False]
@inlineCallbacks
def fn2():
fn2_called[0] = True
yield
returnValue("someretval")
retval = deferred_result(fn())
assert fn2_called[0]
assert not after_noreturn_reached[0]
assert retval == "someretval"
