Remove use of .device in contrib. (quantumlib#4821)

Another sub-component for quantumlib#4744 . This removes the use of `circuit.device` from all contrib modules.

BREAKING_CHANGE=removing the `device` property from the `SwapNetwork` class.
It also removes some type checking done by the code (all logic in the bulk still works), which makes it more forgiving.

With the amount of meaningful maintenance contrib has had (not much), I'm not a huge fan of going through a deprecation process for these mild behavior widenings with no API changes. Are others alright with this ?

cirq/contrib/acquaintance/devices.py

@@ -41,15 +41,9 @@ def validate_operation(self, operation: 'cirq.Operation') -> None:
             )
 
 
-def is_acquaintance_strategy(circuit: 'cirq.Circuit') -> bool:
-    return isinstance(circuit._device, AcquaintanceDevice)
-
-
 def get_acquaintance_size(obj: Union[circuits.Circuit, ops.Operation]) -> int:
     """The maximum number of qubits to be acquainted with each other."""
     if isinstance(obj, circuits.Circuit):
-        if not is_acquaintance_strategy(obj):
-            raise TypeError('not is_acquaintance_strategy(circuit)')
         return max(tuple(get_acquaintance_size(op) for op in obj.all_operations()) or (0,))
     if not isinstance(obj, ops.Operation):
         raise TypeError('not isinstance(obj, (Circuit, Operation))')

cirq/contrib/acquaintance/devices_test.py

@@ -28,14 +28,3 @@ def test_acquaintance_device():
     swap_network = cca.SwapNetworkGate((1, 2, 1))
     cca.UnconstrainedAcquaintanceDevice.validate_operation(cca.acquaint(*qubits[:2]))
     cca.UnconstrainedAcquaintanceDevice.validate_operation(swap_network(*qubits))
-
-
-def test_get_acquaintance_size():
-    with pytest.raises(TypeError):
-        cca.get_acquaintance_size(cirq.Circuit())
-
-    with pytest.raises(TypeError):
-        cca.get_acquaintance_size(3)
-
-    circuit = cirq.Circuit(device=cca.UnconstrainedAcquaintanceDevice)
-    cca.get_acquaintance_size(circuit)

cirq/contrib/acquaintance/executor.py

@@ -20,7 +20,6 @@
 from cirq import circuits, devices, ops, protocols
 
 from cirq.contrib.acquaintance.gates import AcquaintanceOpportunityGate
-from cirq.contrib.acquaintance.devices import is_acquaintance_strategy
 from cirq.contrib.acquaintance.permutation import (
     PermutationGate,
     LogicalIndex,
@@ -74,10 +73,7 @@ def __init__(self, execution_strategy: ExecutionStrategy) -> None:
         self.mapping = execution_strategy.initial_mapping.copy()
 
     def __call__(self, strategy: 'cirq.Circuit'):
-        if not is_acquaintance_strategy(strategy):
-            raise TypeError('not is_acquaintance_strategy(strategy)')
         expose_acquaintance_gates(strategy)
-        strategy.device = self.execution_strategy.device
         super().optimize_circuit(strategy)
         return self.mapping.copy()
 

cirq/contrib/acquaintance/executor_test.py

@@ -54,9 +54,6 @@ def test_executor_explicit():
         bad_gates = {(0,): ExampleGate(['0']), (0, 1): ExampleGate(['0', '1'])}
         cca.GreedyExecutionStrategy(bad_gates, initial_mapping)
 
-    with pytest.raises(TypeError):
-        executor(cirq.Circuit())
-
     with pytest.raises(TypeError):
         bad_strategy = cirq.Circuit(cirq.X(qubits[0]))
         executor(bad_strategy)

cirq/contrib/acquaintance/gates_test.py

@@ -135,7 +135,7 @@ def test_acquaint_part_pairs(part_lens):
         n_qubits += part_len
     qubits = cirq.LineQubit.range(n_qubits)
     swap_network_op = cca.SwapNetworkGate(part_lens, acquaintance_size=None)(*qubits)
-    swap_network = cirq.Circuit(swap_network_op, device=cca.UnconstrainedAcquaintanceDevice)
+    swap_network = cirq.Circuit(swap_network_op)
     initial_mapping = {q: i for i, q in enumerate(qubits)}
 
     actual_opps = cca.get_logical_acquaintance_opportunities(swap_network, initial_mapping)

cirq/contrib/acquaintance/inspection_utils.py

@@ -59,7 +59,7 @@ def get_acquaintance_dag(strategy: 'cirq.Circuit', initial_mapping: LogicalMappi
         for op in moment.operations
         if isinstance(op, AcquaintanceOperation)
     )
-    return circuits.CircuitDag.from_ops(acquaintance_ops, device=strategy.device)
+    return circuits.CircuitDag.from_ops(acquaintance_ops)
 
 
 def get_logical_acquaintance_opportunities(

cirq/contrib/acquaintance/mutation_utils.py

@@ -19,7 +19,7 @@
 from cirq import circuits, ops, optimizers
 
 from cirq.contrib.acquaintance.gates import SwapNetworkGate, AcquaintanceOpportunityGate
-from cirq.contrib.acquaintance.devices import is_acquaintance_strategy, get_acquaintance_size
+from cirq.contrib.acquaintance.devices import get_acquaintance_size
 from cirq.contrib.acquaintance.permutation import PermutationGate
 
 if TYPE_CHECKING:
@@ -41,10 +41,6 @@ def rectify_acquaintance_strategy(circuit: 'cirq.Circuit', acquaint_first: bool
     Raises:
         TypeError: If the circuit is not an acquaintance strategy.
     """
-
-    if not is_acquaintance_strategy(circuit):
-        raise TypeError('not is_acquaintance_strategy(circuit)')
-
     rectified_moments = []
     for moment in circuit:
         gate_type_to_ops: Dict[bool, List[ops.GateOperation]] = collections.defaultdict(list)
@@ -85,10 +81,6 @@ def replace_acquaintance_with_swap_network(
     Raises:
         TypeError: circuit is not an acquaintance strategy.
     """
-
-    if not is_acquaintance_strategy(circuit):
-        raise TypeError('not is_acquaintance_strategy(circuit)')
-
     rectify_acquaintance_strategy(circuit)
     reflected = False
     reverse_map = {q: r for q, r in zip(qubit_order, reversed(qubit_order))}

cirq/contrib/acquaintance/mutation_utils_test.py

@@ -142,9 +142,6 @@ def test_complete_acquaintance_strategy():
 def test_rectification():
     qubits = cirq.LineQubit.range(4)
 
-    with pytest.raises(TypeError):
-        cca.rectify_acquaintance_strategy(cirq.Circuit())
-
     perm_gate = cca.SwapPermutationGate()
     operations = [
         perm_gate(*qubits[:2]),
@@ -153,7 +150,7 @@ def test_rectification():
         perm_gate(*qubits[2:]),
     ]
 
-    strategy = cirq.Circuit(operations, device=cca.UnconstrainedAcquaintanceDevice)
+    strategy = cirq.Circuit(operations)
     cca.rectify_acquaintance_strategy(strategy)
     actual_text_diagram = strategy.to_text_diagram().strip()
     expected_text_diagram = """
@@ -167,7 +164,7 @@ def test_rectification():
     """.strip()
     assert actual_text_diagram == expected_text_diagram
 
-    strategy = cirq.Circuit(operations, device=cca.UnconstrainedAcquaintanceDevice)
+    strategy = cirq.Circuit(operations)
     cca.rectify_acquaintance_strategy(strategy, False)
     actual_text_diagram = strategy.to_text_diagram()
     expected_text_diagram = """
@@ -180,9 +177,3 @@ def test_rectification():
 3: ─────────█───────1↦0───
     """.strip()
     assert actual_text_diagram == expected_text_diagram
-
-
-def test_replace_acquaintance_with_swap_network():
-    with pytest.raises(TypeError):
-        qubits = cirq.LineQubit.range(3)
-        cca.replace_acquaintance_with_swap_network(cirq.Circuit(), qubits)

cirq/contrib/acquaintance/optimizers.py

@@ -16,7 +16,6 @@
 
 from cirq import ops
 
-from cirq.contrib.acquaintance.devices import is_acquaintance_strategy
 from cirq.contrib.acquaintance.gates import acquaint
 from cirq.contrib.acquaintance.executor import AcquaintanceOperation
 from cirq.contrib.acquaintance.mutation_utils import expose_acquaintance_gates
@@ -28,8 +27,6 @@
 
 def remove_redundant_acquaintance_opportunities(strategy: 'cirq.Circuit') -> int:
     """Removes redundant acquaintance opportunities."""
-    if not is_acquaintance_strategy(strategy):
-        raise TypeError('not is_acquaintance_strategy(circuit)')
 
     qubits = sorted(strategy.all_qubits())
     mapping = {q: i for i, q in enumerate(qubits)}

cirq/contrib/acquaintance/optimizers_test.py

@@ -11,26 +11,17 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
-import pytest
-
 import cirq
 import cirq.testing as ct
 import cirq.contrib.acquaintance as cca
 
 
 def test_remove_redundant_acquaintance_opportunities():
-    device = cca.UnconstrainedAcquaintanceDevice
     a, b, c, d, e = cirq.LineQubit.range(5)
     swap = cca.SwapPermutationGate()
 
-    with pytest.raises(TypeError):
-        ops = [cca.acquaint(a, b)]
-        strategy = cirq.Circuit(ops)
-        cca.remove_redundant_acquaintance_opportunities(strategy)
-
     ops = [cca.acquaint(a, b), cca.acquaint(a, b)]
-    strategy = cirq.Circuit(ops, device=device)
+    strategy = cirq.Circuit(ops)
     diagram_before = """
 0: ───█───█───
       │   │
@@ -47,7 +38,7 @@ def test_remove_redundant_acquaintance_opportunities():
     ct.assert_has_diagram(strategy, diagram_after)
 
     ops = [cca.acquaint(a, b), cca.acquaint(c, d), swap(d, e), swap(c, d), cca.acquaint(d, e)]
-    strategy = cirq.Circuit(ops, device=device)
+    strategy = cirq.Circuit(ops)
     diagram_before = """
 0: ───█───────────────────
       │

cirq/contrib/acquaintance/shift_swap_network_test.py

@@ -34,7 +34,7 @@ def test_shift_swap_network_gate_acquaintance_opps(left_part_lens, right_part_le
     gate = cca.ShiftSwapNetworkGate(left_part_lens, right_part_lens)
     n_qubits = gate.qubit_count()
     qubits = cirq.LineQubit.range(n_qubits)
-    strategy = cirq.Circuit(gate(*qubits), device=cca.UnconstrainedAcquaintanceDevice)
+    strategy = cirq.Circuit(gate(*qubits))
 
     # actual_opps
     initial_mapping = {q: i for i, q in enumerate(qubits)}

cirq/contrib/acquaintance/strategies/complete.py

@@ -16,7 +16,6 @@
 
 from cirq import circuits, ops
 
-from cirq.contrib.acquaintance.devices import UnconstrainedAcquaintanceDevice
 from cirq.contrib.acquaintance.gates import acquaint
 from cirq.contrib.acquaintance.mutation_utils import (
     expose_acquaintance_gates,
@@ -47,16 +46,14 @@ def complete_acquaintance_strategy(
     if acquaintance_size < 0:
         raise ValueError('acquaintance_size must be non-negative.')
     if acquaintance_size == 0:
-        return circuits.Circuit(device=UnconstrainedAcquaintanceDevice)
+        return circuits.Circuit()
 
     if acquaintance_size > len(qubit_order):
-        return circuits.Circuit(device=UnconstrainedAcquaintanceDevice)
+        return circuits.Circuit()
     if acquaintance_size == len(qubit_order):
-        return circuits.Circuit(acquaint(*qubit_order), device=UnconstrainedAcquaintanceDevice)
+        return circuits.Circuit(acquaint(*qubit_order))
 
-    strategy = circuits.Circuit(
-        (acquaint(q) for q in qubit_order), device=UnconstrainedAcquaintanceDevice
-    )
+    strategy = circuits.Circuit((acquaint(q) for q in qubit_order))
     for size_to_acquaint in range(2, acquaintance_size + 1):
         expose_acquaintance_gates(strategy)
         replace_acquaintance_with_swap_network(strategy, qubit_order, size_to_acquaint, swap_gate)

cirq/contrib/acquaintance/strategies/cubic.py

@@ -16,7 +16,6 @@
 from typing import Iterable, Sequence, Tuple, TypeVar, TYPE_CHECKING
 
 from cirq import circuits, ops
-from cirq.contrib.acquaintance.devices import UnconstrainedAcquaintanceDevice
 from cirq.contrib.acquaintance.gates import acquaint
 from cirq.contrib.acquaintance.permutation import LinearPermutationGate, SwapPermutationGate
 
@@ -77,4 +76,4 @@ def cubic_acquaintance_strategy(
                 )
                 moments.append(moment)
         index_order = new_index_order[::-1]
-    return circuits.Circuit(moments, device=UnconstrainedAcquaintanceDevice)
+    return circuits.Circuit(moments)

cirq/contrib/acquaintance/strategies/quartic_paired.py

@@ -15,7 +15,6 @@
 from typing import cast, Iterable, List, Sequence, Tuple, TYPE_CHECKING
 
 from cirq import circuits, ops
-from cirq.contrib.acquaintance.devices import UnconstrainedAcquaintanceDevice
 from cirq.contrib.acquaintance.gates import acquaint, SwapNetworkGate
 from cirq.contrib.acquaintance.mutation_utils import expose_acquaintance_gates
 
@@ -61,7 +60,7 @@ def quartic_paired_acquaintance_strategy(
     qubits = qubit_pairs_to_qubit_order(qubit_pairs)
     n_qubits = len(qubits)
     swap_network = SwapNetworkGate((1,) * n_qubits, 2)(*qubits)
-    strategy = circuits.Circuit(swap_network, device=UnconstrainedAcquaintanceDevice)
+    strategy = circuits.Circuit(swap_network)
     expose_acquaintance_gates(strategy)
     for i in reversed(range(0, n_qubits, 2)):
         moment = ops.Moment([acquaint(*qubits[j : j + 4]) for j in range(i % 4, n_qubits - 3, 4)])

cirq/contrib/paulistring/recombine.py

@@ -104,6 +104,4 @@ def move_pauli_strings_into_circuit(
 
     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
-    )
+    return circuits.Circuit(output_ops, strategy=circuits.InsertStrategy.EARLIEST)

cirq/contrib/routing/greedy.py

@@ -89,9 +89,7 @@ def route_circuit_greedily(
     router.route()
 
     swap_network = router.swap_network
-    swap_network.circuit = circuits.Circuit(
-        swap_network.circuit.all_operations(), device=swap_network.device
-    )
+    swap_network.circuit = circuits.Circuit(swap_network.circuit.all_operations())
     return swap_network
 
 

cirq/contrib/routing/swap_network.py

@@ -36,7 +36,9 @@ class SwapNetwork:
     """
 
     def __init__(
-        self, circuit: 'cirq.Circuit', initial_mapping: Dict['cirq.Qid', 'cirq.Qid']
+        self,
+        circuit: 'cirq.Circuit',
+        initial_mapping: Dict['cirq.Qid', 'cirq.Qid'],
     ) -> None:
         if not all(isinstance(i, ops.Qid) for I in initial_mapping.items() for i in I):
             raise ValueError('Mapping must be from Qids to Qids.')
@@ -56,10 +58,6 @@ def __eq__(self, other) -> bool:
             return NotImplemented
         return self.circuit == other.circuit and self.initial_mapping == other.initial_mapping
 
-    @property
-    def device(self) -> 'cirq.Device':
-        return self.circuit.device
-
     def __str__(self) -> str:
         circuit = self.circuit.copy()
         cca.display_mapping(circuit, self.initial_mapping)

cirq/protocols/qasm.py

@@ -159,7 +159,9 @@ def qasm(
             kwargs['args'] = args
         if qubits is not None:
             kwargs['qubits'] = tuple(qubits)
+        # pylint: disable=not-callable
         result = method(**kwargs)
+        # pylint: enable=not-callable
     if result is not None and result is not NotImplemented:
         return result