def _convert_list(x):
if len(x) >= 2 and x[-1] is Ellipsis:
p = convert(x[-2])
x = x[:-2]
else:
p = null
for e in reversed(x):
p = Pair(convert(e), p)
return p
def no_item(val, pred):
val = convert(val)
def _goal(state):
a = walk(val, state[0])
if type(a) is Var:
cons = state[2]
cons[a].append(_goal)
return Unit(state)
if pred(a):
return MZero()
stream = Unit(state)
if isinstance(a, tuple):
for e in a:
stream = stream.bind(no_item(e, pred))
return stream
return _goal
def no_item(val, pred):
val = convert(val)
def _goal(state):
a = walk(val, state[0])
if type(a) is Var:
cons = state[2]
cons[a].append(_goal)
return Unit(state)
if type(a) is Pair:
return Unit(state).\
bind(no_item(a.car, pred)).\
bind(no_item(a.cdr, pred))
if pred(a):
return MZero()
return Unit(state)
return _goal
u: 1,
v: 2
}),
((u, v), (1, 2), {
u: 1
}, [v], {
u: 1,
v: 2
}),
((u, v), (1, 2), {
u: 2
}, None, None),
(u, (1, u), {}, None, None),
([u, v], [1, 2], {}, [u, v], {
u: 1,
v: 2
}),
([u, v, ...], [1, 2], {}, [u, v], {
u: 1,
v: convert([2])
}),
([u, v], (1, 2), {}, None, None),
]
@pytest.mark.parametrize("u, v, subst, expected, extended", UNIFY_DATA)
def test_unify(u, v, subst, expected, extended):
assert unify(u, v, subst) == expected
if expected is not None:
assert subst == extended
b = Var()
GOALS_DATA = [
(eq(a, 1), [{a: 1}]),
(disj(eq(a, 1), eq(a, 2)), [{a: 1}, {a: 2}]),
(conj(eq(a, 1), eq(a, 1)), [{a: 1}]),
(conj(eq(a, 1), eq(a, 2)), []),
(eqt(a, int), [{}]),
(conj(eq(a, 1), eqt(a, int)), [{a: 1}]),
(conj(eqt(a, int), eq(a, 1)), [{a: 1}]),
(conj(eq(a, 1), eqt(a, str)), []),
(conj(eqt(a, str), eq(a, 1)), []),
(conj(eqt(a, int), eqt(a, int)), [{}]),
(conj(eqt(a, int), eqt(a, str)), []),
(conj(conj(eqt(a, int), eqt(b, int)), eq(a, b)), [{a: b}]),
(conj(conj(eqt(a, int), eqt(b, str)), eq(a, b)), []),
(conj(conj(eq(a, [1]), eq(b, 1)), eq(a, [b])), [{a: convert([1]), b: 1}]),
(conj(conj(eq(a, [b]), eq(b, 1)), eq(a, [1])), [{a: convert([b]), b: 1}]),
(conj(conj(eq(a, [b]), eq(b, 1)), eq(a, [2])), [])
]
@pytest.mark.parametrize("goal, expected", GOALS_DATA)
def test_goals(goal, expected):
assert [s for s, _, _ in unfold(goal(initial()))] == expected