def test_prev_moment_operating_on_distance():
a = cirq.QubitId()
c = Circuit([
Moment(),
Moment([cirq.X(a)]),
Moment(),
Moment(),
Moment(),
Moment(),
])
assert c.prev_moment_operating_on([a], max_distance=4) is None
assert c.prev_moment_operating_on([a], 6, max_distance=4) is None
assert c.prev_moment_operating_on([a], 5, max_distance=3) is None
assert c.prev_moment_operating_on([a], 4, max_distance=2) is None
assert c.prev_moment_operating_on([a], 3, max_distance=1) is None
assert c.prev_moment_operating_on([a], 2, max_distance=0) is None
assert c.prev_moment_operating_on([a], 1, max_distance=0) is None
assert c.prev_moment_operating_on([a], 0, max_distance=0) is None
assert c.prev_moment_operating_on([a], 6, max_distance=5) == 1
assert c.prev_moment_operating_on([a], 5, max_distance=4) == 1
assert c.prev_moment_operating_on([a], 4, max_distance=3) == 1
assert c.prev_moment_operating_on([a], 3, max_distance=2) == 1
assert c.prev_moment_operating_on([a], 2, max_distance=1) == 1
assert c.prev_moment_operating_on([a], 6, max_distance=10) == 1
assert c.prev_moment_operating_on([a], 6, max_distance=100) == 1
assert c.prev_moment_operating_on([a], 13, max_distance=500) == 1
# Huge max distances should be handled quickly due to capping.
assert c.prev_moment_operating_on([a], 1, max_distance=10**100) is None
def test_prev_moment_operating_on():
a = cirq.QubitId()
b = cirq.QubitId()
c = Circuit()
assert c.prev_moment_operating_on([a]) is None
assert c.prev_moment_operating_on([a], 0) is None
assert c.prev_moment_operating_on([a], 102) is None
c = Circuit([Moment([cirq.X(a)])])
assert c.prev_moment_operating_on([a]) == 0
assert c.prev_moment_operating_on([a], 1) == 0
assert c.prev_moment_operating_on([a, b]) == 0
assert c.prev_moment_operating_on([a], 0) is None
assert c.prev_moment_operating_on([b]) is None
c = Circuit([
Moment([cirq.CZ(a, b)]),
Moment(),
Moment([cirq.X(a)]),
Moment(),
])
assert c.prev_moment_operating_on([a], 4) == 2
assert c.prev_moment_operating_on([a], 3) == 2
assert c.prev_moment_operating_on([a], 2) == 0
assert c.prev_moment_operating_on([a], 1) == 0
assert c.prev_moment_operating_on([a], 0) is None
assert c.prev_moment_operating_on([b], 4) == 0
assert c.prev_moment_operating_on([b], 3) == 0
assert c.prev_moment_operating_on([b], 2) == 0
assert c.prev_moment_operating_on([b], 1) == 0
assert c.prev_moment_operating_on([b], 0) is None
assert c.prev_moment_operating_on([a, b], 4) == 2
assert c.prev_moment_operating_on([a, b], 3) == 2
assert c.prev_moment_operating_on([a, b], 2) == 0
assert c.prev_moment_operating_on([a, b], 1) == 0
assert c.prev_moment_operating_on([a, b], 0) is None
