Deprecate the final_step_result parameter of TrialResult

cirq-core/cirq/contrib/quimb/mps_simulator.py

@@ -26,7 +26,7 @@
 
 from cirq import devices, protocols, qis, value
 from cirq._compat import deprecated_parameter
-from cirq.sim import simulator_base
+from cirq.sim import simulator, simulator_base
 from cirq.sim.act_on_args import ActOnArgs
 
 if TYPE_CHECKING:
@@ -122,35 +122,36 @@ def _create_simulator_trial_result(
         self,
         params: 'cirq.ParamResolver',
         measurements: Dict[str, np.ndarray],
-        final_step_result: 'MPSSimulatorStepResult',
+        final_simulator_state: 'cirq.OperationTarget[MPSState]',
     ) -> 'MPSTrialResult':
         """Creates a single trial results with the measurements.
 
         Args:
             params: A ParamResolver for determining values of Symbols.
             measurements: A dictionary from measurement key (e.g. qubit) to the
                 actual measurement array.
-            final_step_result: The final step result of the simulation.
+            final_simulator_state: The final state of the simulation.
 
         Returns:
             A single result.
         """
         return MPSTrialResult(
-            params=params, measurements=measurements, final_step_result=final_step_result
+            params=params, measurements=measurements, final_simulator_state=final_simulator_state
         )
 
 
 class MPSTrialResult(simulator_base.SimulationTrialResultBase['MPSState']):
     """A single trial reult"""
 
+    @simulator._deprecated_step_result_parameter(old_position=3)
     def __init__(
         self,
         params: 'cirq.ParamResolver',
         measurements: Dict[str, np.ndarray],
-        final_step_result: 'MPSSimulatorStepResult',
+        final_simulator_state: 'cirq.OperationTarget[MPSState]',
     ) -> None:
         super().__init__(
-            params=params, measurements=measurements, final_step_result=final_step_result
+            params=params, measurements=measurements, final_simulator_state=final_simulator_state
         )
 
     @property

cirq-core/cirq/contrib/quimb/mps_simulator_test.py

@@ -1,7 +1,6 @@
 # pylint: disable=wrong-or-nonexistent-copyright-notice
 import itertools
 import math
-from unittest import mock
 
 import numpy as np
 import pytest
@@ -263,8 +262,7 @@ def test_measurement_str():
 
 def test_trial_result_str():
     q0 = cirq.LineQubit(0)
-    final_step_result = mock.Mock(cirq.StepResult)
-    final_step_result._simulator_state.return_value = ccq.mps_simulator.MPSState(
+    final_simulator_state = ccq.mps_simulator.MPSState(
         qubits=(q0,),
         prng=value.parse_random_state(0),
         simulation_options=ccq.mps_simulator.MPSOptions(),
@@ -274,7 +272,7 @@ def test_trial_result_str():
             ccq.mps_simulator.MPSTrialResult(
                 params=cirq.ParamResolver({}),
                 measurements={'m': np.array([[1]])},
-                final_step_result=final_step_result,
+                final_simulator_state=final_simulator_state,
             )
         )
         == """measurements: m=1
@@ -286,16 +284,15 @@ def test_trial_result_str():
 
 def test_trial_result_repr_pretty():
     q0 = cirq.LineQubit(0)
-    final_step_result = mock.Mock(cirq.StepResult)
-    final_step_result._simulator_state.return_value = ccq.mps_simulator.MPSState(
+    final_simulator_state = ccq.mps_simulator.MPSState(
         qubits=(q0,),
         prng=value.parse_random_state(0),
         simulation_options=ccq.mps_simulator.MPSOptions(),
     )
     result = ccq.mps_simulator.MPSTrialResult(
         params=cirq.ParamResolver({}),
         measurements={'m': np.array([[1]])},
-        final_step_result=final_step_result,
+        final_simulator_state=final_simulator_state,
     )
     cirq.testing.assert_repr_pretty(
         result,

cirq-core/cirq/sim/clifford/act_on_stabilizer_ch_form_args.py

@@ -16,6 +16,7 @@
 
 import numpy as np
 
+from cirq._compat import proper_repr
 from cirq.sim.clifford import stabilizer_state_ch_form
 from cirq.sim.clifford.act_on_stabilizer_args import ActOnStabilizerArgs
 
@@ -65,3 +66,11 @@ def __init__(
         super().__init__(
             state=initial_state, prng=prng, qubits=qubits, classical_data=classical_data
         )
+
+    def __repr__(self) -> str:
+        return (
+            'cirq.ActOnStabilizerCHFormArgs('
+            f'initial_state={proper_repr(self.state)},'
+            f' qubits={self.qubits!r},'
+            f' classical_data={self.classical_data!r})'
+        )

cirq-core/cirq/sim/clifford/clifford_simulator.py

@@ -36,7 +36,7 @@
 import cirq
 from cirq import protocols, value
 from cirq.protocols import act_on
-from cirq.sim import clifford, simulator_base
+from cirq.sim import clifford, simulator, simulator_base
 
 
 class CliffordSimulator(
@@ -107,25 +107,26 @@ def _create_simulator_trial_result(
         self,
         params: 'cirq.ParamResolver',
         measurements: Dict[str, np.ndarray],
-        final_step_result: 'CliffordSimulatorStepResult',
+        final_simulator_state: 'cirq.OperationTarget[cirq.ActOnStabilizerCHFormArgs]',
     ):
 
         return CliffordTrialResult(
-            params=params, measurements=measurements, final_step_result=final_step_result
+            params=params, measurements=measurements, final_simulator_state=final_simulator_state
         )
 
 
 class CliffordTrialResult(
     simulator_base.SimulationTrialResultBase['clifford.ActOnStabilizerCHFormArgs']
 ):
+    @simulator._deprecated_step_result_parameter(old_position=3)
     def __init__(
         self,
         params: 'cirq.ParamResolver',
         measurements: Dict[str, np.ndarray],
-        final_step_result: 'cirq.CliffordSimulatorStepResult',
+        final_simulator_state: 'cirq.OperationTarget[cirq.ActOnStabilizerCHFormArgs]',
     ) -> None:
         super().__init__(
-            params=params, measurements=measurements, final_step_result=final_step_result
+            params=params, measurements=measurements, final_simulator_state=final_simulator_state
         )
 
     @property
@@ -137,7 +138,7 @@ def final_state(self) -> 'cirq.CliffordState':
 
     def __str__(self) -> str:
         samples = super().__str__()
-        final = self._final_simulator_state
+        final = self._get_merged_sim_state().state
         return f'measurements: {samples}\noutput state: {final}'
 
     def _repr_pretty_(self, p: Any, cycle: bool):

cirq-core/cirq/sim/clifford/clifford_simulator_test.py

@@ -1,6 +1,5 @@
 # pylint: disable=wrong-or-nonexistent-copyright-notice
 import itertools
-from unittest import mock
 
 import numpy as np
 import pytest
@@ -212,32 +211,33 @@ def test_clifford_state_initial_state():
 
 def test_clifford_trial_result_repr():
     q0 = cirq.LineQubit(0)
-    final_step_result = mock.Mock(cirq.CliffordSimulatorStepResult)
-    final_step_result._simulator_state.return_value = cirq.CliffordState(qubit_map={q0: 0})
+    final_simulator_state = cirq.ActOnStabilizerCHFormArgs(qubits=[q0])
     assert (
         repr(
             cirq.CliffordTrialResult(
                 params=cirq.ParamResolver({}),
                 measurements={'m': np.array([[1]])},
-                final_step_result=final_step_result,
+                final_simulator_state=final_simulator_state,
             )
         )
         == "cirq.SimulationTrialResult(params=cirq.ParamResolver({}), "
         "measurements={'m': array([[1]])}, "
-        "final_simulator_state=StabilizerStateChForm(num_qubits=1))"
+        "final_simulator_state=cirq.ActOnStabilizerCHFormArgs("
+        "initial_state=StabilizerStateChForm(num_qubits=1), "
+        "qubits=(cirq.LineQubit(0),), "
+        "classical_data=cirq.ClassicalDataDictionaryStore()))"
     )
 
 
 def test_clifford_trial_result_str():
     q0 = cirq.LineQubit(0)
-    final_step_result = mock.Mock(cirq.CliffordSimulatorStepResult)
-    final_step_result._simulator_state.return_value = cirq.CliffordState(qubit_map={q0: 0})
+    final_simulator_state = cirq.ActOnStabilizerCHFormArgs(qubits=[q0])
     assert (
         str(
             cirq.CliffordTrialResult(
                 params=cirq.ParamResolver({}),
                 measurements={'m': np.array([[1]])},
-                final_step_result=final_step_result,
+                final_simulator_state=final_simulator_state,
             )
         )
         == "measurements: m=1\n"
@@ -247,12 +247,11 @@ def test_clifford_trial_result_str():
 
 def test_clifford_trial_result_repr_pretty():
     q0 = cirq.LineQubit(0)
-    final_step_result = mock.Mock(cirq.CliffordSimulatorStepResult)
-    final_step_result._simulator_state.return_value = cirq.CliffordState(qubit_map={q0: 0})
+    final_simulator_state = cirq.ActOnStabilizerCHFormArgs(qubits=[q0])
     result = cirq.CliffordTrialResult(
         params=cirq.ParamResolver({}),
         measurements={'m': np.array([[1]])},
-        final_step_result=final_step_result,
+        final_simulator_state=final_simulator_state,
     )
 
     cirq.testing.assert_repr_pretty(result, "measurements: m=1\n" "output state: |0⟩")

cirq-core/cirq/sim/density_matrix_simulator.py

@@ -17,7 +17,7 @@
 import numpy as np
 
 from cirq import ops, protocols, study, value
-from cirq._compat import deprecated_parameter, proper_repr
+from cirq._compat import deprecated_class, deprecated_parameter, proper_repr
 from cirq.sim import simulator, act_on_density_matrix_args, simulator_base
 
 if TYPE_CHECKING:
@@ -186,10 +186,10 @@ def _create_simulator_trial_result(
         self,
         params: 'cirq.ParamResolver',
         measurements: Dict[str, np.ndarray],
-        final_step_result: 'cirq.DensityMatrixStepResult',
+        final_simulator_state: 'cirq.OperationTarget[cirq.ActOnDensityMatrixArgs]',
     ) -> 'cirq.DensityMatrixTrialResult':
         return DensityMatrixTrialResult(
-            params=params, measurements=measurements, final_step_result=final_step_result
+            params=params, measurements=measurements, final_simulator_state=final_simulator_state
         )
 
     # TODO(#4209): Deduplicate with identical code in sparse_simulator.
@@ -310,6 +310,7 @@ def __repr__(self) -> str:
         )
 
 
+@deprecated_class(deadline='v0.16', fix='This class is no longer used.')
 @value.value_equality(unhashable=True)
 class DensityMatrixSimulatorState:
     """The simulator state for DensityMatrixSimulator
@@ -380,14 +381,15 @@ class DensityMatrixTrialResult(
             trial finishes.
     """
 
+    @simulator._deprecated_step_result_parameter(old_position=3)
     def __init__(
         self,
         params: 'cirq.ParamResolver',
         measurements: Dict[str, np.ndarray],
-        final_step_result: 'cirq.DensityMatrixStepResult',
+        final_simulator_state: 'cirq.OperationTarget[cirq.ActOnDensityMatrixArgs]',
     ) -> None:
         super().__init__(
-            params=params, measurements=measurements, final_step_result=final_step_result
+            params=params, measurements=measurements, final_simulator_state=final_simulator_state
         )
         self._final_density_matrix: Optional[np.ndarray] = None
 
@@ -418,7 +420,7 @@ def __repr__(self) -> str:
         return (
             'cirq.DensityMatrixTrialResult('
             f'params={self.params!r}, measurements={proper_repr(self.measurements)}, '
-            f'final_step_result={self._final_step_result!r})'
+            f'final_simulator_state={self._final_simulator_state!r})'
         )
 
     def _repr_pretty_(self, p: Any, cycle: bool):