def test_name_conflict(self):
# Shouldn't cause any problems
foobar1 = MultiMethod('foobar', identity)
foobar2 = MultiMethod('foobar', identity)
@foobar1.method(1)
def foobar1(x):
return "foobar1"
@foobar2.method(2)
def foobar2(selfx):
return "foobar2"
self.assertEqual(foobar1(1), "foobar1")
self.assertEqual(foobar2(2), "foobar2")
def test_basics(self):
speaksum = MultiMethod('speaksum', lambda *a: sum(a))
@speaksum.method(2)
def _speaksum2(x, y, z):
return "Two"
@speaksum.method(5)
def _speaksum5(x, y):
return "Five"
@speaksum.method(0)
def _speaksum0(x, y):
return "Zero"
@speaksum.method(Default)
def _speaksum_d(x, y, z):
return "Another"
self.assertEqual(speaksum(1, 1, 0), "Two")
self.assertEqual(speaksum(3, 2), "Five")
self.assertEqual(speaksum(9, 8, 2), "Another")
self.assertEqual(speaksum(3, 5, 6), "Another")
self.assertEqual(speaksum(-1, 1), "Zero")
# Too many arguments to method
self.assertRaises(TypeError, lambda: speaksum(2, 3, 0, 0, 0))
def test_addmethod(self):
foomethod = MultiMethod('foomethod', identity)
foomethod.add_method(42, lambda x: "The Answer")
foomethod.add_method(1024, lambda x: "2^10")
foomethod.add_method(Default, lambda x: "Nothing")
self.assertEqual(foomethod(42), "The Answer")
self.assertEqual(foomethod(1024), "2^10")
self.assertEqual(foomethod(Default), "Nothing")
def test_unbound_function(self):
'''
The value of pass_self is completely irrelevant for 'unbound' free-functions
'''
mm = MultiMethod('mm', type_dispatch, pass_self=True)
@mm.method(Default)
def mm_default(value):
return value
self.assertEqual(mm('hello world'), 'hello world')
def test_falsey_values(self):
foobar3 = MultiMethod('foobar3', identity)
@foobar3.method(0)
def foobar30(x):
return "zero"
@foobar3.method(None)
def foobar3n(x):
return "none"
self.assertEqual(foobar3(0), "zero")
self.assertEqual(foobar3(False), "zero") # in python False == 0
self.assertEqual(foobar3(None), "none")
def test_prefer_not_needed_on_same_method(self):
bar = MultiMethod('bar', type_dispatch)
@bar.method((object, str))
@bar.method((str, object))
def barstr(x, y):
return "os " + str(x) + str(y)
@bar.method((int, int))
def other(x, y):
return 5
self.assertEqual(bar("sdf", "dgf"), "os sdfdgf")
self.assertEqual(bar(3, 6), 5)
class Dispatch(unittest.TestCase):
discount = MultiMethod('tests.Dispatch.discount', lambda name, item: (len(name), type(item)))
@discount.method((5, ExpensiveItem))
def dis_25(name, item):
return 25
@discount.method((10, ExpensiveItem))
def dis_30(name, item):
return 30
@discount.method((Anything, ExpensiveItem))
def dis_15(name, item):
return 15
@discount.method((5, Item))
def dis_5(name, item):
return 5
discount.prefer((Anything, ExpensiveItem), (5, Item))
@discount.method(Default)
def default(name, item):
return 0
myitem = BoxedItem()
def test_hierarchy(self):
self.assertEqual(self.discount("steve", ExpensiveItem()), 25)
self.assertEqual(self.discount("chrisjones", ExpensiveItem()), 30)
self.assertEqual(self.discount("steve", BoxedItem()), 5)
self.assertEqual(self.discount("joe", Item()), 0)
def test_anything(self):
self.assertEqual(self.discount("joe", ExpensiveItem()), 15)
def test_cache(self):
self.assertEqual(self.discount("steve", self.myitem), 5)
#self.assertEqual(self.discount("myverylongname", self.myitem), 30)
self.assertIn((5, BoxedItem), self.discount.cache)
class IsA(unittest.TestCase):
class Version(object):
def __init__(self, version):
self.version = version
def __str__(self):
return "<Version %s>" % str(self.version)
something = MultiMethod('tests.isA.something', lambda v: IsA.Version(v))
@something.method(Version(25))
def something_25(foo):
return 25
@something.method(Version(30))
def something_30(foo):
return 30
@something.method(Version(15))
def something_15(foo):
return 15
@something.method(Version(5))
def something_5(foo):
return 5
@something.method(Default)
def default(foo):
return 0
@is_a.method((Version, Version))
def _is_a_version(x, y):
return x.version >= y.version
def test_is_a(self):
self.assertEqual(self.something(31), 30)
self.assertEqual(self.something(6), 5)
self.assertEqual(self.something(-10), 0)
self.assertEqual(self.something(25), 25)
class PassSelfMultiMethod(unittest.TestCase):
mm = MultiMethod('mm', type_dispatch, pass_self=True)
@mm.method(Default)
def mm_default(self, value):
return self, 'default', value
@mm.method((dict,))
def mm_int(self, value):
return self, 'dict', value
@mm.method((str,))
def mm_str(self, value):
return self, 'str', value
@mm.method((float,))
def mm_str(self, value):
return self, 'float', value
def test_pass_self(self):
self.assertEqual(self.mm({}), (self, 'dict', {}))
self.assertEqual(self.mm(12345), (self, 'default', 12345))
self.assertEqual(self.mm(123.45), (self, 'float', 123.45))
self.assertEqual(self.mm('foo'), (self, 'str', 'foo'))
def test_unbound_function(self):
'''
The value of pass_self is completely irrelevant for 'unbound' free-functions
'''
mm = MultiMethod('mm', type_dispatch, pass_self=True)
@mm.method(Default)
def mm_default(value):
return value
self.assertEqual(mm('hello world'), 'hello world')
def test_removemethod(self):
barmethod = MultiMethod('barmethod', identity)
@barmethod.method(1)
def barmethod1(x):
return 123
self.assertEqual(barmethod(1), 123)
barmethod.remove_method(1)
self.assertRaises(Exception, lambda: barmethod(1))
@barmethod.method(Default)
def barmethod_d(x):
return 42
self.assertEqual(barmethod("whatever"), 42)
self.assertEqual(barmethod("something"), 42)
barmethod.remove_method(Default)
self.assertRaises(Exception, lambda: barmethod("whatever"))
self.assertRaises(Exception, lambda: barmethod(1))
class Prefer(unittest.TestCase):
pref = MultiMethod('pref', type_dispatch)
class MyList(list):
pass
@pref.method(Default)
def pd(x, y):
return "default"
@pref.method((Iterable, object))
def pio(x, y):
return "io"
@pref.method((object, Iterable))
def poi(x, y):
return "oi"
@pref.method((list, object))
def plo(x, y):
return "lo"
@pref.method((object, list))
def pol(x, y):
return "ol"
@pref.method((Iterable, list))
def pil(x, y):
return "il"
@pref.method((list, Iterable))
def pli(x, y):
return "li"
@pref.method((str, object))
def pso(x, y):
return "so"
@pref.method((object, str))
def pos(x, y):
return "os"
#pref.prefer((str, object), (object, str))
pref.prefer((object, Iterable), (Iterable, object))
def test_ambiguous(self):
self.assertEqual(self.pref(5, 6), "default")
self.assertRaises(DispatchException, self.pref, "sdf", "dgf")
# def test_prefer(self):
# self.assertEqual(self.pref(Prefer.MyList(), Prefer.MyList()), "lo")
def test_prefer_not_needed_on_same_method(self):
bar = MultiMethod('bar', type_dispatch)
@bar.method((object, str))
@bar.method((str, object))
def barstr(x, y):
return "os " + str(x) + str(y)
@bar.method((int, int))
def other(x, y):
return 5
self.assertEqual(bar("sdf", "dgf"), "os sdfdgf")
self.assertEqual(bar(3, 6), 5)
