Deperecate {ion,neutral_atom}.qubit_set.

cirq-core/cirq/ion/ion_device.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 from typing import Any, FrozenSet, Iterable, Optional, Set, TYPE_CHECKING
+import networkx as nx
 from cirq import _compat, circuits, value, devices, ops, protocols
 from cirq.ion import convert_to_ion_gates
 
@@ -70,6 +71,18 @@ def __init__(
         self.qubits = frozenset(qubits)
         self.gateset = get_ion_gateset()
 
+        graph = nx.Graph()
+        graph.add_edges_from([(a, b) for a in qubits for b in qubits if a != b], directed=False)
+        self._metadata = devices.DeviceMetadata(self.qubits, graph)
+
+    @property
+    def metadata(self) -> devices.DeviceMetadata:
+        return self._metadata
+
+    @_compat.deprecated(
+        fix='Use metadata.qubit_set if applicable.',
+        deadline='v0.15',
+    )
     def qubit_set(self) -> FrozenSet['cirq.LineQubit']:
         return self.qubits
 

cirq-core/cirq/ion/ion_device_test.py

@@ -65,6 +65,14 @@ def test_init():
         )
 
 
+def test_metadata():
+    d = ion_device(3)
+    assert d.metadata.qubit_set == frozenset(
+        {cirq.LineQubit(0), cirq.LineQubit(1), cirq.LineQubit(2)}
+    )
+    assert len(d.metadata.nx_graph.edges()) == 3
+
+
 def test_init_timedelta():
     d = ion_device(3, use_timedelta=True)
     ms = 1000 * cirq.Duration(nanos=1)
@@ -209,8 +217,9 @@ def test_at():
     assert d.at(2) == cirq.LineQubit(2)
 
 
-def test_qubit_set():
-    assert ion_device(3).qubit_set() == frozenset(cirq.LineQubit.range(3))
+def test_qubit_set_deprecated():
+    with cirq.testing.assert_deprecated('qubit_set', deadline='v0.15'):
+        assert ion_device(3).qubit_set() == frozenset(cirq.LineQubit.range(3))
 
 
 def test_qid_pairs_deprecated():

cirq-core/cirq/neutral_atoms/neutral_atom_devices.py

@@ -116,6 +116,15 @@ def __init__(
                 raise ValueError(f'Unsupported qubit type: {q!r}')
         self.qubits = frozenset(qubits)
 
+        self._metadata = devices.GridDeviceMetadata(
+            [(a, b) for a in self.qubits for b in self.qubits if a.is_adjacent(b)], self.gateset
+        )
+
+    @property
+    def metadata(self) -> devices.GridDeviceMetadata:
+        return self._metadata
+
+    @_compat.deprecated(fix='Use metadata.qubit_set if applicable.', deadline='v0.15')
     def qubit_set(self) -> FrozenSet['cirq.GridQubit']:
         return self.qubits
 

cirq-core/cirq/neutral_atoms/neutral_atom_devices_test.py

@@ -56,6 +56,21 @@ def test_init():
         _ = d.duration_of(cirq.SingleQubitGate().on(q00))
 
 
+def test_metadata():
+    d = square_device(2, 3)
+    assert d.metadata.qubit_set == frozenset(
+        {
+            cirq.GridQubit(0, 0),
+            cirq.GridQubit(0, 1),
+            cirq.GridQubit(1, 0),
+            cirq.GridQubit(1, 1),
+            cirq.GridQubit(2, 0),
+            cirq.GridQubit(2, 1),
+        }
+    )
+    assert len(d.metadata.nx_graph.edges()) == 7
+
+
 def test_init_timedelta():
     d = square_device(2, 2, holes=[cirq.GridQubit(1, 1)], use_timedelta=True)
     us = cirq.Duration(nanos=10 ** 3)
@@ -282,5 +297,6 @@ def test_repr_pretty():
     cirq.testing.assert_repr_pretty(square_device(2, 2), "cirq.NeutralAtomDevice(...)", cycle=True)
 
 
-def test_qubit_set():
-    assert square_device(2, 2).qubit_set() == frozenset(cirq.GridQubit.square(2, 0, 0))
+def test_qubit_set_deprecated():
+    with cirq.testing.assert_deprecated('qubit_set', deadline='v0.15'):
+        assert square_device(2, 2).qubit_set() == frozenset(cirq.GridQubit.square(2, 0, 0))