add MSGate to top level

Author: prakharb10

cirq-core/cirq/__init__.py

@@ -240,6 +240,7 @@
     MatrixGate,
     MixedUnitaryChannel,
     M,
+    MSGate,
     measure,
     measure_each,
     measure_paulistring_terms,

cirq-core/cirq/json_resolver_cache.py

@@ -157,6 +157,7 @@ def _symmetricalqidpair(qids):
         'LineTopology': cirq.LineTopology,
         'Linspace': cirq.Linspace,
         'ListSweep': cirq.ListSweep,
+        'MSGate': cirq.MSGate,
         'MatrixGate': cirq.MatrixGate,
         'MixedUnitaryChannel': cirq.MixedUnitaryChannel,
         'MeasurementKey': cirq.MeasurementKey,

cirq-core/cirq/ops/parity_gates_test.py

@@ -258,7 +258,7 @@ def test_trace_distance():
 def test_ms_arguments():
     eq_tester = cirq.testing.EqualsTester()
     eq_tester.add_equality_group(
-        cirq.ms(np.pi / 2), cirq.ops.MSGate(rads=np.pi / 2), cirq.XXPowGate(global_shift=-0.5)
+        cirq.ms(np.pi / 2), cirq.MSGate(rads=np.pi / 2), cirq.XXPowGate(global_shift=-0.5)
     )
     eq_tester.add_equality_group(
         cirq.ms(np.pi / 4), cirq.XXPowGate(exponent=0.5, global_shift=-0.5)
@@ -325,7 +325,7 @@ def test_ms_diagrams():
 def test_json_serialization():
     def custom_resolver(cirq_type: str):
         if cirq_type == "MSGate":
-            return cirq.ops.MSGate
+            return cirq.MSGate
         return None
 
     assert cirq.read_json(

cirq-core/cirq/protocols/json_test_data/MSGate.json

@@ -0,0 +1,4 @@
+{
+  "cirq_type": "MSGate",
+  "rads": 1.5707963267948966
+}

cirq-core/cirq/protocols/json_test_data/MSGate.repr

@@ -0,0 +1 @@
+cirq.ms(np.pi/2)