def test_lazy_orcall(self):
def from_mimetype(request):
# you can return both value or Option
return request.get("mimetype", None)
def from_extension(request):
# you can return both value or Option
return monad.Option(request.get("url", None))\
.map(lambda s: s.split(".")[-1])
# extract value from extension
r = dict(url="myfile.png")
self.assertEqual("PNG", monad.Option(r.get("type", None)) \
.or_call(from_mimetype, r) \
.or_call(from_extension, r) \
.map(operator.methodcaller("upper")) \
.get_or(""))
# extract value from mimetype
r = dict(url="myfile.svg", mimetype="png")
self.assertEqual("PNG", monad.Option(r.get("type", None)) \
.or_call(from_mimetype, r) \
.or_call(from_extension, r) \
.map(operator.methodcaller("upper")) \
.get_or(""))
# type is set directly
r = dict(url="myfile.jpeg", mimetype="svg", type="png")
self.assertEqual("PNG", monad.Option(r.get("type", None)) \
.or_call(from_mimetype, r) \
.or_call(from_extension, r) \
.map(operator.methodcaller("upper")) \
.get_or(""))
def test_create_option(self):
self.assertIsInstance(monad.Option("A"), monad.Full)
self.assertIsInstance(monad.Option(10), monad.Full)
self.assertIsInstance(monad.Option(10, lambda x: x > 7), monad.Full)
self.assertIsInstance(monad.Option(None), monad.Empty)
self.assertIsInstance(monad.Option(False), monad.Full)
self.assertIsInstance(monad.Option(0), monad.Full)
self.assertIsInstance(monad.Option(False, checker=bool), monad.Empty)
self.assertIsInstance(monad.Option(0, checker=bool), monad.Empty)
self.assertIsInstance(monad.Option(10, lambda x: x > 70), monad.Empty)
def test_option_repr(self):
self.assertEqual("Full(10)", repr(monad.Full(10)))
self.assertEqual("Full(in box!)", repr(monad.Full("in box!")))
self.assertEqual("Empty()", repr(monad.Empty()))
self.assertEqual("Empty()", repr(monad.Option(None)))
def test_stringify(self):
self.assertEqual("Full(10)", str(monad.Full(10)))
self.assertEqual("Full(in box!)", str(monad.Full("in box!")))
self.assertEqual("Empty()", str(monad.Empty()))
self.assertEqual("Empty()", str(monad.Option(None)))
def from_extension(request):
# you can return both value or Option
return monad.Option(request.get("url", None))\
.map(lambda s: s.split(".")[-1])
def test_empty_check(self):
self.assertTrue(monad.Empty().empty)
self.assertTrue(monad.Option(None).empty)
self.assertTrue(monad.Option.from_call(lambda: None).empty)
self.assertFalse(monad.Option(10).empty)
self.assertFalse(monad.Full(10).empty)
def parameter(self, name):
return monad.Option(self.get(name, None))
