Add SerializableGateSet.is_supported (#3410)

This method checks if a given object containing operations (a circuit, moment, or other arbitrary op tree) is supported by a gateset. Note that this does not address separating the notions of belonging to a gateset from serializability, but at it provides a way to check if a circuit is supported without actually serializing, which can be expensive.

cirq/google/serializable_gate_set.py

@@ -86,15 +86,18 @@ def with_added_gates(
     def supported_gate_types(self) -> Tuple:
         return tuple(self.serializers.keys())
 
+    def is_supported(self, op_tree: 'cirq.OP_TREE') -> bool:
+        """Whether the given object contains only supported operations."""
+        return all(
+            self.is_supported_operation(op)
+            for op in ops.flatten_to_ops(op_tree))
+
     def is_supported_operation(self, op: 'cirq.Operation') -> bool:
         """Whether or not the given gate can be serialized by this gate set."""
-        gate = op.gate
-        for gate_type_mro in type(gate).mro():
-            if gate_type_mro in self.serializers:
-                for serializer in self.serializers[gate_type_mro]:
-                    if serializer.can_serialize_operation(op):
-                        return True
-        return False
+        return any(
+            serializer.can_serialize_operation(op)
+            for gate_type in type(op.gate).mro()
+            for serializer in self.serializers.get(gate_type, []))
 
     def serialize(self,
                   program: 'cirq.Circuit',

cirq/google/serializable_gate_set_test.py

@@ -83,6 +83,12 @@ def test_supported_gate_types():
     assert MY_GATE_SET.supported_gate_types() == (cirq.XPowGate,)
 
 
+def test_is_supported():
+    q0, q1 = cirq.GridQubit.rect(1, 2)
+    assert MY_GATE_SET.is_supported(cirq.Circuit(cirq.X(q0), cirq.X(q1)))
+    assert not MY_GATE_SET.is_supported(cirq.Circuit(cirq.X(q0), cirq.Z(q1)))
+
+
 def test_is_supported_operation():
     q = cirq.GridQubit(1, 1)
     assert MY_GATE_SET.is_supported_operation(cirq.XPowGate()(q))