def applyo_goal(S):
nonlocal o_rator, o_rands, obj
o_rator_rf, o_rands_rf, obj_rf = reify((o_rator, o_rands, obj), S)
if not isvar(obj_rf):
# We should be able to use this goal with *any* arguments, so
# fail when the ground operations fail/err.
try:
obj_rator, obj_rands = operator(obj_rf), arguments(obj_rf)
except (ConsError, NotImplementedError):
return
# The object's rator + rands should be the same as the goal's
yield from lall(eq(o_rator_rf, obj_rator),
eq(o_rands_rf, obj_rands))(S)
elif isvar(o_rands_rf) or isvar(o_rator_rf):
# The object and at least one of the rand, rators is a logic
# variable, so let's just assert a `cons` relationship between
# them
yield from conso(o_rator_rf, o_rands_rf, obj_rf)(S)
else:
# The object is a logic variable, but the rator and rands aren't.
# We assert that the object is the application of the rand and
# rators.
try:
obj_applied = term(o_rator_rf, o_rands_rf)
except (ConsError, NotImplementedError):
return
yield from eq(obj_rf, obj_applied)(S)
def test_isvar():
assert not isvar(3)
assert isvar(var(3))
class CustomVar(Var):
pass
assert isvar(CustomVar())
def _unify_ConstrainedVar_object(u, v, s):
u_w = walk(u, s)
if isvar(v):
v_w = walk(v, s)
else:
v_w = v
if u_w == v_w:
yield s
elif isvar(u_w):
if (not isvar(v_w) and isinstance(u_w, ConstrainedVar)
and not u_w.constraint(eval_if_etuple(v_w))):
yield False
return
yield assoc(s, u_w, v_w)
elif isvar(v_w):
if (not isvar(u_w) and isinstance(v_w, ConstrainedVar)
and not v_w.constraint(eval_if_etuple(u_w))):
yield False
return
yield assoc(s, v_w, u_w)
else:
yield _unify(u_w, v_w, s)
def test_context_manager():
with variables(1):
assert isvar(1)
assert not isvar(1)
def test_isvar():
assert not isvar(3)
assert isvar(var(3))
def test_isvar():
assert not isvar(3)
assert isvar(var(3))
def test_context_manager():
with variables(1):
assert isvar(1)
assert not isvar(1)