def test_term():
X = Var()
Y = Var()
t1 = Term("f", [Atom.newatom("hallo"), X])
t2 = Term("f", [Y, Atom.newatom("HALLO")])
heap = Heap()
print t1, t2
t1.unify(t2, heap)
assert X.getvalue(heap).name == "HALLO"
assert Y.getvalue(heap).name == "hallo"
def test_var():
b = Var()
heap = Heap()
b.unify(Atom.newatom("hallo"), heap)
assert b.getvalue(heap).name == "hallo"
a = Var()
b = Var()
a.unify(b, heap)
a.unify(Atom.newatom("hallo"), heap)
assert a.getvalue(heap).name == "hallo"
assert b.getvalue(heap).name == "hallo"
def test_run():
e = Engine()
e.add_rule(Term("f", [Atom.newatom("a"), Atom.newatom("b")]))
X = Var()
Y = Var()
e.add_rule(Term("f", [X, X]))
e.add_rule(Term(":-", [Term("f", [X, Y]),
Term("f", [Y, X])]))
X = e.heap.newvar()
e.run(Term("f", [Atom.newatom("b"), X]))
assert X.dereference(e.heap).name == "b"
e.run(Term("f", [Atom.newatom("b"), Atom.newatom("a")]))
def test_atom():
a = Atom.newatom("hallo")
b = Atom.newatom("hallo")
# does not raise
a.unify(b, None)
py.test.raises(UnificationFailed, "a.unify(Atom.newatom('xxx'), None)")
def test_unify_var():
b = Var()
heap = Heap()
b.unify(b, heap)
b.unify(Atom.newatom("hallo"), heap)
py.test.raises(UnificationFailed, b.unify, Atom.newatom("bye"), heap)
