Remove uses of .device in cirq-pasqal in preparation for larger circuit.device deprecation (quantumlib#4757)

First devices removal as a part of quantumlib#4744 .

The high level plan for deprecation is to:

1. pull all components of the library off of `.device` and onto `._device` to keep existing behavior working.
2. Deprecate dependent functionality that relies on `.device`.
3. After all dependency deprecations are done, deprecate the `.device` property in `cirq-core` circuits.py.
4. After the deprecation cycle is over, delete .device and _device properties from circuit, abstractcircuit, frozencircuit etc.

This PR is tackles `cirq-pasqal`.

Author: MichaelBroughton

cirq-core/cirq/circuits/circuit.py

@@ -125,6 +125,9 @@ def moments(self) -> Sequence['cirq.Moment']:
     def device(self) -> 'cirq.Device':
         pass
 
+    # This is going away once device deprecation is finished.
+    _device = None  # type: devices.Device
+
     def freeze(self) -> 'cirq.FrozenCircuit':
         """Creates a FrozenCircuit from this circuit.
 

cirq-pasqal/cirq_pasqal/pasqal_device_test.py

@@ -164,7 +164,6 @@ def with_qubits(self, *new_qubits):
 
 def test_validate_operation_errors():
     d = generic_device(3)
-    circuit = cirq.Circuit(device=d)
 
     with pytest.raises(ValueError, match="Unsupported operation"):
         d.validate_operation(cirq.NamedQubit('q0'))
@@ -178,15 +177,20 @@ def test_validate_operation_errors():
     with pytest.raises(ValueError, match="is not part of the device."):
         d.validate_operation(cirq.X.on(cirq.NamedQubit('q6')))
 
+    d = square_virtual_device(control_r=1.0, num_qubits=3)
+    with pytest.raises(ValueError, match="are too far away"):
+        d.validate_operation(cirq.CZ.on(TwoDQubit(0, 0), TwoDQubit(2, 2)))
+
+
+def test_validate_operation_errors_deprecated():
+    d = generic_device(3)
+    circuit = cirq.Circuit()
+    circuit._device = d
     with pytest.raises(
         NotImplementedError, match="Measurements on Pasqal devices don't support invert_mask."
     ):
         circuit.append(cirq.measure(*d.qubits, invert_mask=(True, False, False)))
 
-    d = square_virtual_device(control_r=1.0, num_qubits=3)
-    with pytest.raises(ValueError, match="are too far away"):
-        d.validate_operation(cirq.CZ.on(TwoDQubit(0, 0), TwoDQubit(2, 2)))
-
 
 def test_validate_moment():
     d = square_virtual_device(control_r=1.0, num_qubits=2)
@@ -202,7 +206,7 @@ def test_validate_moment():
 
 def test_validate_circuit():
     d = generic_device(2)
-    circuit1 = cirq.Circuit(device=d)
+    circuit1 = cirq.Circuit()
     circuit1.append(cirq.X(cirq.NamedQubit('q1')))
     circuit1.append(cirq.measure(cirq.NamedQubit('q1')))
     d.validate_circuit(circuit1)

cirq-pasqal/cirq_pasqal/pasqal_noise_model_test.py

@@ -42,7 +42,7 @@ def test_noisy_moments():
     circuit = cirq.Circuit()
     circuit.append(cirq.ops.CZ(p_qubits[0], p_qubits[1]))
     circuit.append(cirq.ops.Z(p_qubits[1]))
-    p_circuit = cirq.Circuit(circuit, device=p_device)
+    p_circuit = cirq.Circuit(circuit)
 
     n_mts = []
     for moment in p_circuit._moments:
@@ -65,7 +65,7 @@ def test_default_noise():
     circuit = cirq.Circuit()
     Gate_l = cirq.ops.CZPowGate(exponent=2)
     circuit.append(Gate_l.on(p_qubits[0], p_qubits[1]))
-    p_circuit = cirq.Circuit(circuit, device=p_device)
+    p_circuit = cirq.Circuit(circuit)
     n_mts = []
     for moment in p_circuit._moments:
         n_mts.append(noise_model.noisy_moment(moment, p_qubits))

cirq-pasqal/cirq_pasqal/pasqal_sampler.py

@@ -21,15 +21,20 @@
 
 
 class PasqalSampler(cirq.work.Sampler):
-    def __init__(self, remote_host: str, access_token: str = '') -> None:
+    def __init__(
+        self, remote_host: str, access_token: str = '', device: cirq_pasqal.PasqalDevice = None
+    ) -> None:
         """Inits PasqalSampler.
 
         Args:
             remote_host: Address of the remote device.
             access_token: Access token for the remote api.
+            device: Optional cirq_pasqal.PasqalDevice to use with
+                the sampler.
         """
         self.remote_host = remote_host
         self._authorization_header = {"Authorization": access_token}
+        self._device = device
 
     def _serialize_circuit(
         self,
@@ -100,6 +105,20 @@ def _send_serialized_circuit(
 
         return result
 
+    @cirq._compat.deprecated_parameter(
+        deadline='v0.15',
+        fix='The program.device component is going away.'
+        'Attaching a device to PasqalSampler is now done in __init__.',
+        parameter_desc='program',
+        match=lambda args, kwargs: (
+            len(args) >= 2
+            and isinstance(args[1], cirq.AbstractCircuit)
+            and args[1]._device != cirq.UNCONSTRAINED_DEVICE
+        )
+        or 'program' in kwargs
+        and isinstance(kwargs['program'], cirq.AbstractCircuit)
+        and kwargs['program']._device != cirq.UNCONSTRAINED_DEVICE,
+    )
     def run_sweep(
         self, program: cirq.AbstractCircuit, params: cirq.study.Sweepable, repetitions: int = 1
     ) -> List[cirq.study.Result]:
@@ -114,8 +133,11 @@ def run_sweep(
             Result list for this run; one for each possible parameter
             resolver.
         """
-        assert isinstance(program.device, cirq_pasqal.PasqalDevice)
-        program.device.validate_circuit(program)
+        device = program._device if program._device != cirq.UNCONSTRAINED_DEVICE else self._device
+        assert isinstance(
+            device, cirq_pasqal.PasqalDevice
+        ), "Device must inherit from cirq.PasqalDevice."
+        device.validate_circuit(program)
         trial_results = []
 
         for param_resolver in cirq.study.to_resolvers(params):

cirq-pasqal/cirq_pasqal/pasqal_sampler_test.py

@@ -36,18 +36,19 @@ def text(self):
             return self.json
 
 
-def _make_sampler() -> cirq_pasqal.PasqalSampler:
+def _make_sampler(device) -> cirq_pasqal.PasqalSampler:
 
-    sampler = cirq_pasqal.PasqalSampler(remote_host='http://00.00.00/', access_token='N/A')
+    sampler = cirq_pasqal.PasqalSampler(
+        remote_host='http://00.00.00/', access_token='N/A', device=device
+    )
     return sampler
 
 
 def test_pasqal_circuit_init():
     qs = cirq.NamedQubit.range(3, prefix='q')
     ex_circuit = cirq.Circuit()
     ex_circuit.append([[cirq.CZ(qs[i], qs[i + 1]), cirq.X(qs[i + 1])] for i in range(len(qs) - 1)])
-    device = cirq_pasqal.PasqalDevice(qubits=qs)
-    test_circuit = cirq.Circuit(device=device)
+    test_circuit = cirq.Circuit()
     test_circuit.append(
         [[cirq.CZ(qs[i], qs[i + 1]), cirq.X(qs[i + 1])] for i in range(len(qs) - 1)]
     )
@@ -74,22 +75,22 @@ def test_run_sweep(mock_post, mock_get):
     binary = bin(num)[2:].zfill(9)
 
     device = cirq_pasqal.PasqalVirtualDevice(control_radius=1, qubits=qs)
-    ex_circuit = cirq.Circuit(device=device)
+    ex_circuit = cirq.Circuit()
 
     for i, b in enumerate(binary[:-1]):
         if b == '1':
             ex_circuit.append(cirq.X(qs[-i - 1]), strategy=cirq.InsertStrategy.NEW)
 
     ex_circuit_odd = copy.deepcopy(ex_circuit)
-    ex_circuit_odd.append(cirq.X(qs[0]))
-    ex_circuit_odd.append(cirq.measure(*qs))
+    ex_circuit_odd.append(cirq.X(qs[0]), strategy=cirq.InsertStrategy.NEW)
+    ex_circuit_odd.append(cirq.measure(*qs), strategy=cirq.InsertStrategy.NEW)
 
     xpow = cirq.XPowGate(exponent=par)
-    ex_circuit.append([xpow(qs[0])])
-    ex_circuit.append(cirq.measure(*qs))
+    ex_circuit.append([xpow(qs[0])], strategy=cirq.InsertStrategy.NEW)
+    ex_circuit.append(cirq.measure(*qs), strategy=cirq.InsertStrategy.NEW)
 
     mock_get.return_value = MockGet(cirq.to_json(ex_circuit_odd))
-    sampler = _make_sampler()
+    sampler = _make_sampler(device)
 
     with pytest.raises(ValueError, match="Non-empty moment after measurement"):
         wrong_circuit = copy.deepcopy(ex_circuit)
@@ -102,3 +103,42 @@ def test_run_sweep(mock_post, mock_get):
     assert cirq.read_json(json_text=submitted_json) == ex_circuit_odd
     assert mock_post.call_count == 2
     assert data[1] == ex_circuit_odd
+
+
+@patch('cirq_pasqal.pasqal_sampler.requests.get')
+@patch('cirq_pasqal.pasqal_sampler.requests.post')
+def test_run_sweep_device_deprecated(mock_post, mock_get):
+    """Test running a sweep.
+
+    Encodes a random binary number in the qubits, sweeps between odd and even
+    without noise and checks if the results match.
+    """
+
+    qs = [cirq_pasqal.ThreeDQubit(i, j, 0) for i in range(3) for j in range(3)]
+
+    par = sympy.Symbol('par')
+    sweep = cirq.Linspace(key='par', start=0.0, stop=1.0, length=2)
+
+    num = np.random.randint(0, 2 ** 9)
+    binary = bin(num)[2:].zfill(9)
+
+    device = cirq_pasqal.PasqalVirtualDevice(control_radius=1, qubits=qs)
+    ex_circuit = cirq.Circuit()
+
+    for i, b in enumerate(binary[:-1]):
+        if b == '1':
+            ex_circuit.append(cirq.X(qs[-i - 1]), strategy=cirq.InsertStrategy.NEW)
+
+    ex_circuit_odd = copy.deepcopy(ex_circuit)
+    ex_circuit_odd.append(cirq.X(qs[0]), strategy=cirq.InsertStrategy.NEW)
+    ex_circuit_odd.append(cirq.measure(*qs), strategy=cirq.InsertStrategy.NEW)
+
+    xpow = cirq.XPowGate(exponent=par)
+    ex_circuit.append([xpow(qs[0])], strategy=cirq.InsertStrategy.NEW)
+    ex_circuit.append(cirq.measure(*qs), strategy=cirq.InsertStrategy.NEW)
+
+    mock_get.return_value = MockGet(cirq.to_json(ex_circuit_odd))
+    sampler = _make_sampler(device)
+    ex_circuit._device = device
+    with cirq.testing.assert_deprecated('The program.device component', deadline='v0.15'):
+        _ = sampler.run_sweep(program=ex_circuit, params=sweep, repetitions=1)