Move optimizers/transformer_primitives.py to transformers/transformer…

…_primitives.py (quantumlib#4746)

cirq-core/cirq/__init__.py

@@ -339,11 +339,6 @@
     EjectZ,
     ExpandComposite,
     is_negligible_turn,
-    map_moments,
-    map_operations,
-    map_operations_and_unroll,
-    merge_moments,
-    merge_operations,
     merge_single_qubit_gates_into_phased_x_z,
     merge_single_qubit_gates_into_phxz,
     MergeInteractions,
@@ -362,6 +357,14 @@
     two_qubit_matrix_to_diagonal_and_operations,
     two_qubit_matrix_to_sqrt_iswap_operations,
     three_qubit_matrix_to_operations,
+)
+
+from cirq.transformers import (
+    map_moments,
+    map_operations,
+    map_operations_and_unroll,
+    merge_moments,
+    merge_operations,
     unroll_circuit_op,
     unroll_circuit_op_greedy_earliest,
     unroll_circuit_op_greedy_frontier,

cirq-core/cirq/optimizers/__init__.py

@@ -97,18 +97,6 @@
     three_qubit_matrix_to_operations,
 )
 
-from cirq.optimizers.transformer_primitives import (
-    map_moments,
-    map_operations,
-    map_operations_and_unroll,
-    merge_moments,
-    merge_operations,
-    unroll_circuit_op,
-    unroll_circuit_op_greedy_earliest,
-    unroll_circuit_op_greedy_frontier,
-)
-
-
 from cirq.optimizers.two_qubit_decompositions import (
     two_qubit_matrix_to_operations,
     two_qubit_matrix_to_diagonal_and_operations,

cirq-core/cirq/transformers/__init__.py

@@ -0,0 +1,26 @@
+# Copyright 2021 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.
+
+"""Circuit transformation utilities."""
+
+from cirq.transformers.transformer_primitives import (
+    map_moments,
+    map_operations,
+    map_operations_and_unroll,
+    merge_moments,
+    merge_operations,
+    unroll_circuit_op,
+    unroll_circuit_op_greedy_earliest,
+    unroll_circuit_op_greedy_frontier,
+)

cirq-core/cirq/optimizers/transformer_primitives_test.py → cirq-core/cirq/transformers/transformer_primitives_test.py

@@ -16,7 +16,7 @@
 import pytest
 
 import cirq
-from cirq.optimizers.transformer_primitives import MAPPED_CIRCUIT_OP_TAG
+from cirq.transformers.transformer_primitives import MAPPED_CIRCUIT_OP_TAG
 
 
 def test_map_operations_can_write_new_gates_inline():