def test_unification(self):
x = V.make_variable("x")
y = V.make_variable("y")
pattern = x.pair(y.pair(x))
value = C.make_const(3).pair(L.pair(C.make_const(2)))
def check():
assert False
pattern.go(value, check)
def test_last(self):
a = V.make_variable('a')
b = V.make_variable('b')
c = V.make_variable('c')
x = V.make_variable('x')
y = V.make_variable('y')
z = V.make_variable('z')
p = Prolog()
p.fact(x.pair(y.pair(x)).make_const("member"))
p.head_body(
x.pair(y.pair(z)).make_const("member"),
x.pair(y).make_const("member"))
p.fact(L.pair(x).pair(x).make_const("append"))
p.head_body(
a.pair(x).pair(b).pair(c.pair(x)).make_const("append"),
a.pair(b).pair(c).make_const("append"))
def do():
for q in [x, y]:
s = []
p.go(
a.pair(q).make_const("member"),
lambda: s.append(a.value()))
w.append(s)
w = []
p.go(
x.pair(y).pair(L.make_const('c').make_const('b').make_const(
'a')).make_const('append'), do)
self.assertEqual(w,
[[], ['a', 'b', 'c'], ['a'], ['b', 'c'], ['a', 'b'],
['c'], ['a', 'b', 'c'], []])
def test_pair(self):
assert L.pair(L).car().value() is None
assert L.pair(L).cdr().value() is None
def test_occur_check(self):
x = V.make_variable('x')
x.go(L.pair(x), lambda: self.assertTrue(False))