def move_pauli_strings_into_circuit(
circuit_left: Union[circuits.Circuit, circuits.CircuitDag],
circuit_right: circuits.Circuit) -> circuits.Circuit:
if isinstance(circuit_left, circuits.CircuitDag):
string_dag = circuits.CircuitDag(pauli_string_reorder_pred,
circuit_left)
else:
string_dag = pauli_string_dag_from_circuit(
cast(circuits.Circuit, circuit_left))
output_ops = list(circuit_right.all_operations())
rightmost_nodes = (set(string_dag.nodes()) -
set(before for before, _ in string_dag.edges()))
while rightmost_nodes:
# Sort the pauli string placements based on paulistring length and
# furthest possible distance in circuit_right
placements = _sorted_best_string_placements(rightmost_nodes,
output_ops)
last_index = len(output_ops)
# Pick the Pauli string that can be moved furthest through
# the Clifford circuit
for best_string_op, best_index, best_node in placements:
assert best_index <= last_index, (
"Unexpected insertion index order,"
" {} >= {}, len: {}".format(best_index, last_index,
len(output_ops)))
last_index = best_index
output_ops.insert(best_index, best_string_op)
# Remove the best one from the dag and update rightmost_nodes
rightmost_nodes.remove(best_node)
rightmost_nodes.update(
pred_node for pred_node in string_dag.predecessors(best_node)
if len(string_dag.succ[pred_node]) <= 1)
string_dag.remove_node(best_node)
assert not string_dag.nodes(), 'There was a cycle in the CircuitDag'
return circuits.Circuit(output_ops,
strategy=circuits.InsertStrategy.EARLIEST,
device=circuit_right.device)
def move_pauli_strings_into_circuit(
circuit_left: Union[circuits.Circuit, circuits.CircuitDag],
circuit_right: circuits.Circuit) -> circuits.Circuit:
if isinstance(circuit_left, circuits.CircuitDag):
string_dag = circuits.CircuitDag(pauli_string_reorder_pred,
circuit_left)
else:
string_dag = pauli_string_dag_from_circuit(
cast(circuits.Circuit, circuit_left))
output_ops = list(circuit_right.all_operations())
rightmost_nodes = (set(string_dag.nodes) -
set(before for before, _ in string_dag.edges))
while rightmost_nodes:
# Pick the Pauli string that can be moved furthest through the Clifford
# circuit
best_string_op, best_index, best_node = max(
_possible_string_placements(rightmost_nodes, output_ops),
key=lambda placement:
(-len(placement[0].pauli_string), placement[1]))
# Place the best one into the output circuit
output_ops.insert(best_index, best_string_op)
# Remove the best one from the dag and update rightmost_nodes
rightmost_nodes.remove(best_node)
rightmost_nodes.update(
pred_node for pred_node in string_dag.predecessors(best_node)
if len(string_dag.succ[pred_node]) <= 1)
string_dag.remove_node(best_node)
assert not string_dag.nodes, 'There was a cycle in the CircuitDag'
return circuits.Circuit.from_ops(output_ops,
strategy=circuits.InsertStrategy.EARLIEST,
device=circuit_right.device)