Deprecate classes and paramters in contrib (quantumlib#5684)

* Deprecate classes and paramters in contrib

- Deprecates parameters in contrib
- Removes MergeNQubits and StrategyExecutor in favor of transformers

Author: dstrain115

cirq/contrib/acquaintance/__init__.py

@@ -21,7 +21,6 @@
 from cirq.contrib.acquaintance.executor import (
     AcquaintanceOperation,
     GreedyExecutionStrategy,
-    StrategyExecutor,
     StrategyExecutorTransformer,
 )
 

cirq/contrib/acquaintance/executor.py

@@ -17,7 +17,7 @@
 import abc
 from collections import defaultdict
 
-from cirq import circuits, devices, ops, protocols, transformers, _compat
+from cirq import circuits, devices, ops, protocols, transformers
 
 from cirq.contrib.acquaintance.gates import AcquaintanceOpportunityGate
 from cirq.contrib.acquaintance.permutation import (
@@ -34,10 +34,10 @@
 
 
 class ExecutionStrategy(metaclass=abc.ABCMeta):
-    """Tells StrategyExecutor how to execute an acquaintance strategy.
+    """Tells `StrategyExecutorTransormer` how to execute an acquaintance strategy.
 
-    An execution strategy tells StrategyExecutor how to execute an
-    acquaintance strategy, i.e. what gates to implement at the available
+    An execution strategy tells `StrategyExecutorTransformer` how to execute
+    an acquaintance strategy, i.e. what gates to implement at the available
     acquaintance opportunities."""
 
     keep_acquaintance = False
@@ -78,45 +78,6 @@ def __call__(self, *args, **kwargs):
         return strategy.mapping
 
 
-@_compat.deprecated_class(
-    deadline='v1.0', fix='Use cirq.contrib.acquaintance.StrategyExecutorTransformer'
-)
-class StrategyExecutor(circuits.PointOptimizer):
-    """Executes an acquaintance strategy."""
-
-    def __init__(self, execution_strategy: ExecutionStrategy) -> None:
-        super().__init__()
-        self.execution_strategy = execution_strategy
-        self.mapping = execution_strategy.initial_mapping.copy()
-
-    def __call__(self, strategy: 'cirq.Circuit'):
-        expose_acquaintance_gates(strategy)
-        super().optimize_circuit(strategy)
-        return self.mapping.copy()
-
-    def optimization_at(
-        self, circuit: 'cirq.Circuit', index: int, op: 'cirq.Operation'
-    ) -> Optional['cirq.PointOptimizationSummary']:
-        if isinstance(op.gate, AcquaintanceOpportunityGate):
-            logical_indices = tuple(self.mapping[q] for q in op.qubits)
-            logical_operations = self.execution_strategy.get_operations(logical_indices, op.qubits)
-            clear_span = int(not self.execution_strategy.keep_acquaintance)
-
-            return circuits.PointOptimizationSummary(
-                clear_span=clear_span, clear_qubits=op.qubits, new_operations=logical_operations
-            )
-
-        if isinstance(op, ops.GateOperation) and isinstance(op.gate, PermutationGate):
-            op.gate.update_mapping(self.mapping, op.qubits)
-            return None
-
-        raise TypeError(
-            'Can only execute a strategy consisting of gates that '
-            'are instances of AcquaintanceOpportunityGate or '
-            'PermutationGate.'
-        )
-
-
 @transformers.transformer
 class StrategyExecutorTransformer:
     """Executes an acquaintance strategy."""

cirq/contrib/acquaintance/executor_test.py

@@ -36,11 +36,7 @@ def _circuit_diagram_info_(self, args: cirq.CircuitDiagramInfoArgs):
         return self._wire_symbols
 
 
-@pytest.mark.parametrize(
-    'StrategyType, is_deprecated',
-    [[cca.StrategyExecutor, True], [cca.StrategyExecutorTransformer, False]],
-)
-def test_executor_explicit(StrategyType, is_deprecated):
+def test_executor_explicit():
     num_qubits = 8
     qubits = cirq.LineQubit.range(num_qubits)
     circuit = cca.complete_acquaintance_strategy(qubits, 2)
@@ -53,19 +49,9 @@ def test_executor_explicit(StrategyType, is_deprecated):
     initial_mapping = {q: i for i, q in enumerate(sorted(qubits))}
     execution_strategy = cca.GreedyExecutionStrategy(gates, initial_mapping)
 
-    if is_deprecated:
-        with cirq.testing.assert_deprecated(
-            "Use cirq.contrib.acquaintance.StrategyExecutorTransformer", deadline='v1.0'
-        ):
-            executor = StrategyType(execution_strategy)
-            with pytest.raises(TypeError):
-                op = cirq.X(qubits[0])
-                bad_strategy = cirq.Circuit(op)
-                executor.optimization_at(bad_strategy, 0, op)
-    else:
-        with pytest.raises(ValueError):
-            executor = StrategyType(None)
-        executor = StrategyType(execution_strategy)
+    with pytest.raises(ValueError):
+        executor = cca.StrategyExecutorTransformer(None)
+    executor = cca.StrategyExecutorTransformer(execution_strategy)
 
     with pytest.raises(NotImplementedError):
         bad_gates = {(0,): ExampleGate(['0']), (0, 1): ExampleGate(['0', '1'])}
@@ -75,10 +61,7 @@ def test_executor_explicit(StrategyType, is_deprecated):
         bad_strategy = cirq.Circuit(cirq.X(qubits[0]))
         executor(bad_strategy)
 
-    if is_deprecated:
-        executor(circuit)
-    else:
-        circuit = executor(circuit)
+    circuit = executor(circuit)
     expected_text_diagram = """
 0: ───0───1───╲0╱─────────────────1───3───╲0╱─────────────────3───5───╲0╱─────────────────5───7───╲0╱─────────────────
       │   │   │                   │   │   │                   │   │   │                   │   │   │

cirq/contrib/paulistring/recombine_test.py

@@ -11,7 +11,6 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-import pytest
 
 import cirq
 from cirq.contrib.paulistring import (
@@ -28,7 +27,6 @@ def _assert_no_multi_qubit_pauli_strings(circuit: cirq.Circuit) -> None:
 
 
 def test_move_non_clifford_into_clifford():
-    cg = pytest.importorskip("cirq_google")
     q0, q1, q2 = cirq.LineQubit.range(3)
     c_orig = cirq.testing.nonoptimal_toffoli_circuit(q0, q1, q2)
 
@@ -43,11 +41,9 @@ def test_move_non_clifford_into_clifford():
     _assert_no_multi_qubit_pauli_strings(c_recombined1)
     _assert_no_multi_qubit_pauli_strings(c_recombined2)
 
-    with cirq.testing.assert_deprecated(
-        'Use cirq.optimize_for_target_gateset', deadline='v0.16', count=None
-    ):
-        baseline_len = len(cg.optimized_for_xmon(c_orig))
-        opt_len1 = len(cg.optimized_for_xmon(c_recombined1))
-        opt_len2 = len(cg.optimized_for_xmon(c_recombined2))
-        assert opt_len1 <= baseline_len
-        assert opt_len2 <= baseline_len
+    gateset = cirq.CZTargetGateset()
+    baseline_len = len(cirq.optimize_for_target_gateset(c_orig, gateset=gateset))
+    opt_len1 = len(cirq.optimize_for_target_gateset(c_recombined1, gateset=gateset))
+    opt_len2 = len(cirq.optimize_for_target_gateset(c_recombined2, gateset=gateset))
+    assert opt_len1 <= baseline_len
+    assert opt_len2 <= baseline_len

cirq/contrib/quimb/__init__.py

@@ -12,11 +12,7 @@
     circuit_to_density_matrix_tensors,
 )
 
-from cirq.contrib.quimb.grid_circuits import (
-    simplify_expectation_value_circuit,
-    MergeNQubitGates,
-    get_grid_moments,
-)
+from cirq.contrib.quimb.grid_circuits import simplify_expectation_value_circuit, get_grid_moments
 
 from cirq.contrib.quimb.mps_simulator import (
     MPSOptions,

cirq/contrib/quimb/grid_circuits.py

@@ -1,5 +1,18 @@
-# pylint: disable=wrong-or-nonexistent-copyright-notice
-from typing import Optional, Iterator
+# Copyright 2022 The Cirq Developers
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from typing import Iterator
 
 import networkx as nx
 
@@ -89,37 +102,6 @@ def _interaction(
     )
 
 
-@cirq._compat.deprecated_class(deadline='v0.16', fix="Use cirq.merge_k_qubit_unitaries")
-class MergeNQubitGates(cirq.PointOptimizer):
-    """Optimizes runs of adjacent unitary n-qubit operations."""
-
-    def __init__(self, *, n_qubits: int):
-        super().__init__()
-        self.n_qubits = n_qubits
-
-    def optimization_at(
-        self, circuit: cirq.Circuit, index: int, op: cirq.Operation
-    ) -> Optional[cirq.PointOptimizationSummary]:
-        if len(op.qubits) != self.n_qubits:
-            return None
-
-        frontier = {q: index for q in op.qubits}
-        op_list = circuit.findall_operations_until_blocked(
-            frontier, is_blocker=lambda next_op: next_op.qubits != op.qubits
-        )
-        if len(op_list) <= 1:
-            return None
-        operations = [op for idx, op in op_list]
-        indices = [idx for idx, op in op_list]
-        matrix = cirq.linalg.dot(*(cirq.unitary(op) for op in operations[::-1]))
-
-        return cirq.PointOptimizationSummary(
-            clear_span=max(indices) + 1 - index,
-            clear_qubits=op.qubits,
-            new_operations=[cirq.MatrixGate(matrix).on(*op.qubits)],
-        )
-
-
 def simplify_expectation_value_circuit(circuit_sand: cirq.Circuit):
     """For low weight operators on low-degree circuits, we can simplify
     the circuit representation of an expectation value.

cirq/contrib/quimb/mps_simulator_test.py

@@ -469,15 +469,16 @@ def test_state_copy():
 
 
 def test_simulation_state_initializer():
+    expected_classical_data = cirq.ClassicalDataDictionaryStore(
+        _records={cirq.MeasurementKey('test'): [(4,)]}
+    )
     s = ccq.mps_simulator.MPSState(
         qubits=(cirq.LineQubit(0),),
         prng=np.random.RandomState(0),
-        classical_data=cirq.ClassicalDataDictionaryStore(
-            _records={cirq.MeasurementKey('test'): [(4,)]}
-        ),
+        classical_data=expected_classical_data,
     )
     assert s.qubits == (cirq.LineQubit(0),)
-    assert s.log_of_measurement_results == {'test': [4]}
+    assert s.classical_data == expected_classical_data
 
 
 def test_act_on_gate():