def singledispatch_example2():
# adapted from functools.singledispatch test case
singledispatch = dispatch_on('arg')
class S(object):
pass
class V(c.Sized, S):
def __len__(self):
return 0
@singledispatch
def g(arg):
return "base"
@g.register(S)
def g_s(arg):
return "s"
@g.register(c.Container)
def g_container(arg):
return "container"
v = V()
assert g(v) == "s"
c.Container.register(V) # add c.Container to the virtual mro of V
assert g(v) == "s" # since the virtual mro is V, Sized, S, Container
return g, V
def singledispatch_example2():
# adapted from functools.singledispatch test case
singledispatch = dispatch_on('arg')
class S(object):
pass
class V(c.Sized, S):
def __len__(self):
return 0
@singledispatch
def g(arg):
return "base"
@g.register(S)
def g_s(arg):
return "s"
@g.register(c.Container)
def g_container(arg):
return "container"
v = V()
assert g(v) == "s"
c.Container.register(V) # add c.Container to the virtual mro of V
assert g(v) == "s" # since the virtual mro is V, Sized, S, Container
return g, V
def singledispatch_example1():
singledispatch = dispatch_on('obj')
@singledispatch
def g(obj):
raise NotImplementedError(type(g))
@g.register(collections.Sized)
def g_sized(object):
return "sized"
@g.register(collections.Iterable)
def g_iterable(object):
return "iterable"
g(C()) # RuntimeError: Ambiguous dispatch: Iterable or Sized?
def singledispatch_example1():
singledispatch = dispatch_on('obj')
@singledispatch
def g(obj):
raise NotImplementedError(type(g))
@g.register(collections.Sized)
def g_sized(object):
return "sized"
@g.register(collections.Iterable)
def g_iterable(object):
return "iterable"
g(C()) # RuntimeError: Ambiguous dispatch: Iterable or Sized?
def test_no_first_arg(self):
@decorator
def example(*args, **kw):
return args[0](*args[1:], **kw)
@example
def func(**kw):
return kw
# there is no confusion when passing args as a keyword argument
self.assertEqual(func(args='a'), {'args': 'a'})
# ################### test dispatch_on ############################# #
# adapted from test_functools in Python 3.5
singledispatch = dispatch_on('obj')
class TestSingleDispatch(unittest.TestCase):
def test_simple_overloads(self):
@singledispatch
def g(obj):
return "base"
@g.register(int)
def g_int(i):
return "integer"
self.assertEqual(g("str"), "base")
self.assertEqual(g(1), "integer")
self.assertEqual(g([1, 2, 3]), "base")
