def test_heap():
h1 = Heap()
v1 = h1.newvar()
v2 = h1.newvar()
h1.add_trail(v1)
v1.binding = 1
h2 = h1.branch()
h2.add_trail(v1)
v1.binding = 2
h2.add_trail(v2)
v2.binding = 3
h3 = h2.revert_upto(h1)
assert v1.binding == 1
assert v2.binding is None
assert h3 is h2
h1 = Heap()
h2 = h1.revert_upto(h1)
assert h2 is h1
h1 = Heap()
h2 = h1.branch()
h3 = h2.revert_upto(h1, discard_choicepoint=True)
assert h3 is h1
def test_heap_discard():
h1 = Heap()
h2 = h1.branch()
h3 = h2.branch()
h = h2.discard(h3)
assert h3.prev is h1
assert h3 is h
h0 = Heap()
v0 = h0.newvar()
h1 = h0.branch()
v1 = h1.newvar()
h2 = h1.branch()
v2 = h2.newvar()
h2.add_trail(v0)
v0.binding = 1
h2.add_trail(v1)
v1.binding = 2
h3 = h2.branch()
h3.add_trail(v2)
v2.binding = 3
h = h2.discard(h3)
assert h3.prev is h1
assert h3 is h
assert h3.revert_upto(h0)
assert v0.binding is None
assert v1.binding is None
assert v2.binding == 3 # not backtracked, because it goes away
def test_heap_discard_variable_shunting():
h0 = Heap()
v0 = h0.newvar()
h1 = h0.branch()
v1a = h1.newvar()
v1b = h1.newvar()
h2 = h1.branch()
v2 = h1.newvar()
h2.add_trail(v0)
v0.binding = 1
h2.add_trail(v1a)
v1a.binding = 2
h = h1.discard(h2)
assert h2.prev is h0
assert h2 is h
assert h1.discarded
assert h1.prev is h2
h2.add_trail(v1b)
v1b.binding = 3
assert h2.revert_upto(h0)
assert v0.binding is None
assert v1a.binding == 2 # not backtracked, because it goes away
assert v1b.binding == 3 # not backtracked, because it goes away
def test_discard_with_attvars():
py.test.skip("not implemented yet")
h0 = Heap()
v0 = h0.new_attvar()
h1 = h0.branch()
v1 = h1.new_attvar()
h2 = h1.branch()
v2 = h2.new_attvar()
h2.add_trail_atts(v0, "m")
v0.atts = {"m": 1}
h2.add_trail_atts(v1, "n")
v1.atts = {"n": 2}
h3 = h2.branch()
h3.add_trail_atts(v2, "a")
v2.atts = {"a": 3}
h = h2.discard(h3)
assert h3.prev is h1
assert h3 is h
assert h3.revert_upto(h0)
assert v0.atts == {}
assert v1.atts == {}
assert v2.atts == {"a": 3}
def test_add_trail_atts():
hp = Heap()
a = hp.new_attvar()
assert a.created_after_choice_point is hp
assert hp.trail_attrs is None
ma = AttMap()
ma.indexes = {"a": 0}
a.value_list = [10]
a.attmap = ma
hp.add_trail_atts(a, "a")
assert hp.trail_attrs is None
hp2 = hp.branch()
hp2.add_trail_atts(a, "a")
assert hp2.trail_attrs == [(a, 0, 10)]
a.add_attribute("a", 20)
assert a.value_list == [20]
hp2._revert()
assert a.value_list == [10]
hp3 = hp2.branch()
hp3.add_trail_atts(a, "b")
a.add_attribute("b", 30)
assert a.value_list == [10, 30]
assert a.attmap.indexes == {"a": 0, "b": 1}
assert a.attmap is not ma
hp3._revert()
assert a.value_list == [10, None]
def test_heap_dont_trail_new():
h1 = Heap()
v1 = h1.newvar()
h1.add_trail(v1)
v1.binding = 1
h2 = h1.branch()
v2 = h2.newvar()
h2.add_trail(v1)
v1.binding = 2
h2.add_trail(v2)
v2.binding = 3
h3 = h2.revert_upto(h1)
assert v1.binding == 1
assert v2.binding == 3 # wasn't undone, because v2 dies
assert h3 is h2
def test_varinterm_bind_later():
h = Heap()
t = Callable.build("a", [Callable.build("b"), NumberedVar(0)])
res = t.copy_standardize_apart(h, [None])
h2 = h.branch()
v = res.argument_at(1)
assert v.dereference(h2) is v
v.unify(Callable.build("c"), h2)
assert res.argument_at(1).dereference(h2).name() == "c"
h2.revert_upto(h)
v2 = res.argument_at(1)
assert v2.dereference(h2) is v2
v.dereference(h2) is v2
v.unify(Callable.build("d"), h2)
assert res.argument_at(1).dereference(h2).name() == "d"
def test_varinterm_bind_later():
h = Heap()
t = Callable.build("a", [Callable.build("b"), NumberedVar(0)])
res = t.copy_standardize_apart(h, [None])
h2 = h.branch()
v = res.argument_at(1)
assert v.dereference(h2) is v
v.unify(Callable.build("c"), h2)
assert res.argument_at(1).dereference(h2).name() == "c"
h2.revert_upto(h)
v2 = res.argument_at(1)
assert v2.dereference(h2) is v2
v.dereference(h2) is v2
v.unify(Callable.build("d"), h2)
assert res.argument_at(1).dereference(h2).name() == "d"
def test_heap_dont_trail_new_attvars():
h1 = Heap()
v1 = h1.new_attvar()
h1.add_trail_atts(v1, "m")
v1.add_attribute("m", 1)
h2 = h1.branch()
v2 = h2.new_attvar()
h2.add_trail_atts(v1, "m")
v1.add_attribute("m", 2)
h2.add_trail_atts(v2, "m")
v2.add_attribute("m", 3)
h3 = h2.revert_upto(h1)
t1 = v1.get_attribute("m")
assert t1[0] == 1
assert t1[1] == 0
t2 = v2.get_attribute("m") # wasn't undone, because v2 dies
assert t2[0] == 3
assert t2[1] == 0
assert h3 is h2