Remove key protocol frozenset conversion (#5660)

Co-authored-by: Cirq Bot <craiggidney+github+cirqbot@google.com>

cirq-core/cirq/protocols/act_on_protocol.py

@@ -16,7 +16,7 @@
 
 from typing_extensions import Protocol
 
-from cirq import _compat, ops
+from cirq import ops
 from cirq._doc import doc_private
 from cirq.type_workarounds import NotImplementedType
 
@@ -86,19 +86,6 @@ def _act_on_(
         """
 
 
-def _fix_deprecated_args(args, kwargs):
-    kwargs['sim_state'] = kwargs['args']
-    del kwargs['args']
-    return args, kwargs
-
-
-@_compat.deprecated_parameter(
-    deadline='v0.16',
-    fix='Change argument name to `sim_state`',
-    parameter_desc='args',
-    match=lambda args, kwargs: 'args' in kwargs,
-    rewrite=_fix_deprecated_args,
-)
 def act_on(
     action: Any,
     sim_state: 'cirq.SimulationStateBase',

cirq-core/cirq/protocols/act_on_protocol_test.py

@@ -96,9 +96,3 @@ def test_qubits_should_be_defined_for_operations():
     state = DummySimulationState()
     with pytest.raises(ValueError, match='Calls to act_on should'):
         cirq.act_on(cirq.KrausChannel([np.array([[1, 0], [0, 0]])]), state, qubits=None)
-
-
-def test_args_deprecated():
-    args = DummySimulationState(fallback_result=True)
-    with cirq.testing.assert_deprecated(deadline='v0.16'):
-        cirq.act_on(action=op, args=args)  # pylint: disable=no-value-for-parameter

cirq-core/cirq/protocols/control_key_protocol.py

@@ -17,7 +17,6 @@
 
 from typing_extensions import Protocol
 
-from cirq import _compat
 from cirq._doc import doc_private
 from cirq.protocols import measurement_key_protocol
 from cirq.type_workarounds import NotImplementedType
@@ -58,12 +57,6 @@ def control_keys(val: Any) -> FrozenSet['cirq.MeasurementKey']:
     getter = getattr(val, '_control_keys_', None)
     result = NotImplemented if getter is None else getter()
     if result is not NotImplemented and result is not None:
-        if not isinstance(result, FrozenSet):
-            _compat._warn_or_error(
-                f'The _control_keys_ implementation of {type(val)} must return a'
-                f' frozenset instead of {type(result)} by v0.16.'
-            )
-            return frozenset(result)
         return result
 
     return frozenset()

cirq-core/cirq/protocols/control_key_protocol_test.py

@@ -27,12 +27,3 @@ def _control_keys_(self):
     assert cirq.control_keys(Named()) == {cirq.MeasurementKey('key')}
     assert not cirq.control_keys(NoImpl())
     assert not cirq.control_keys(5)
-
-
-def test_control_key_enumerable_deprecated():
-    class Deprecated:
-        def _control_keys_(self):
-            return [cirq.MeasurementKey('key')]
-
-    with cirq.testing.assert_deprecated('frozenset', deadline='v0.16'):
-        assert cirq.control_keys(Deprecated()) == {cirq.MeasurementKey('key')}

cirq-core/cirq/protocols/measurement_key_protocol.py

@@ -17,7 +17,7 @@
 
 from typing_extensions import Protocol
 
-from cirq import value, _compat
+from cirq import value
 from cirq._doc import doc_private
 from cirq.type_workarounds import NotImplementedType
 
@@ -182,12 +182,6 @@ def _measurement_key_objs_from_magic_methods(
     getter = getattr(val, '_measurement_key_objs_', None)
     result = NotImplemented if getter is None else getter()
     if result is not NotImplemented and result is not None:
-        if not isinstance(result, FrozenSet):
-            _compat._warn_or_error(
-                f'The _measurement_key_objs_ implementation of {type(val)} must return a'
-                f' frozenset instead of {type(result)} by v0.16.'
-            )
-            return frozenset(result)
         return result
 
     getter = getattr(val, '_measurement_key_obj_', None)
@@ -205,12 +199,6 @@ def _measurement_key_names_from_magic_methods(
     getter = getattr(val, '_measurement_key_names_', None)
     result = NotImplemented if getter is None else getter()
     if result is not NotImplemented and result is not None:
-        if not isinstance(result, FrozenSet):
-            _compat._warn_or_error(
-                f'The _measurement_key_names_ implementation of {type(val)} must return a'
-                f' frozenset instead of {type(result)} by v0.16.'
-            )
-            return frozenset(result)
         return result
 
     getter = getattr(val, '_measurement_key_name_', None)

cirq-core/cirq/protocols/measurement_key_protocol_test.py

@@ -238,18 +238,3 @@ def _with_key_path_(self, path):
     assert cirq.measurement_key_names(mkg_cd) == {'c:d:a', 'c:d:b'}
 
     assert cirq.with_key_path(cirq.X, ('c', 'd')) is NotImplemented
-
-
-def test_measurement_key_enumerable_deprecated():
-    class Deprecated:
-        def _measurement_key_objs_(self):
-            return [cirq.MeasurementKey('key')]
-
-        def _measurement_key_names_(self):
-            return ['key']
-
-    with cirq.testing.assert_deprecated('frozenset', deadline='v0.16'):
-        assert cirq.measurement_key_objs(Deprecated()) == {cirq.MeasurementKey('key')}
-
-    with cirq.testing.assert_deprecated('frozenset', deadline='v0.16'):
-        assert cirq.measurement_key_names(Deprecated()) == {'key'}