def on_gate(self, cmd: GateCmd) -> None:
affected_qubit_ids: Set[int] = {cmd._target_qubit_id
} | cmd._control_qubit_ids
inverse_gate, inverse_params = invert_gate(cmd._gate, cmd._params)
eliminate = True
for qubit_id in affected_qubit_ids:
if not self._commands_stack[qubit_id]:
eliminate = False
continue
_, last_cmd = self._commands_stack[qubit_id][-1]
if not isinstance(last_cmd, GateCmd):
eliminate = False
continue
if last_cmd._control_qubit_ids != cmd._control_qubit_ids:
eliminate = False
if last_cmd._target_qubit_id != cmd._target_qubit_id:
eliminate = False
if last_cmd._gate != inverse_gate:
eliminate = False
if last_cmd._params != inverse_params:
# TODO(adsz): Allow approx.
eliminate = False
if eliminate:
for qubit_id in affected_qubit_ids:
self._commands_stack[qubit_id].pop()
else:
for qubit_id in affected_qubit_ids:
self._commands_stack[qubit_id].append((self._id, cmd))
def inverse_command(command: ICommand):
if not isinstance(command, GateCmd):
raise ValueError(f"Inverse of {type(command)} is impossible.")
inv_gate, inv_params = invert_gate(command._gate, command._params)
return GateCmd(inv_gate, command.get_target_qubit_id(),
command.get_control_qubit_ids(), inv_params)
def test_inverse_u3(self) -> None:
self.assertEqual(invert_gate(U3_GATE, [0, 0, 0]), (U3_GATE, [0, 0, 0]))
self.assertEqual(invert_gate(U3_GATE, [2.2, 3.3, 4.4]),
(U3_GATE, [-2.2, -4.4, -3.3]))
def test_inverse_h(self) -> None:
self.assertEqual(invert_gate(H_GATE, []), (H_GATE, []))