Remove deprecated merge_single_qubit optimizer (#5725)

- This optimizer has moved to transformers.

Author: dstrain115

cirq-core/cirq/__init__.py

@@ -336,11 +336,8 @@
     EjectPhasedPaulis,
     EjectZ,
     ExpandComposite,
-    merge_single_qubit_gates_into_phased_x_z,
-    merge_single_qubit_gates_into_phxz,
     MergeInteractions,
     MergeInteractionsToSqrtIswap,
-    MergeSingleQubitGates,
     SynchronizeTerminalMeasurements,
 )
 

cirq-core/cirq/optimizers/__init__.py

@@ -34,12 +34,6 @@
 
 from cirq.optimizers.merge_interactions_to_sqrt_iswap import MergeInteractionsToSqrtIswap
 
-from cirq.optimizers.merge_single_qubit_gates import (
-    merge_single_qubit_gates_into_phased_x_z,
-    merge_single_qubit_gates_into_phxz,
-    MergeSingleQubitGates,
-)
-
 from cirq.optimizers.synchronize_terminal_measurements import SynchronizeTerminalMeasurements
 
 from cirq.transformers.analytical_decompositions import (

cirq-core/cirq/optimizers/merge_single_qubit_gates.py

@@ -98,7 +98,6 @@
         'MEASUREMENT_KEY_SEPARATOR',
         'MergeInteractions',
         'MergeInteractionsToSqrtIswap',
-        'MergeSingleQubitGates',
         'PointOptimizer',
         'SynchronizeTerminalMeasurements',
         # Transformers

cirq-core/cirq/optimizers/merge_single_qubit_gates_test.py

@@ -30,7 +30,7 @@ def assert_optimizes(optimized: cirq.AbstractCircuit, expected: cirq.AbstractCir
     cirq.testing.assert_same_circuits(optimized, expected)
 
 
-def test_merge_single_qubit_gates_into_phased_x_z():
+def test_merge_single_qubit_gates_to_phased_x_and_z():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit(
         cirq.X(a),
@@ -54,7 +54,7 @@ def test_merge_single_qubit_gates_into_phased_x_z():
     )
 
 
-def test_merge_single_qubit_gates_into_phased_x_z_deep():
+def test_merge_single_qubit_gates_to_phased_x_and_z_deep():
     a = cirq.NamedQubit("a")
     c_nested = cirq.FrozenCircuit(cirq.H(a), cirq.Z(a), cirq.H(a).with_tags("ignore"))
     c_nested_merged = cirq.FrozenCircuit(
@@ -85,7 +85,7 @@ def _phxz(a: float, x: float, z: float):
     return cirq.PhasedXZGate(axis_phase_exponent=a, x_exponent=x, z_exponent=z)
 
 
-def test_merge_single_qubit_gates_into_phxz():
+def test_merge_single_qubit_gates_to_phxz():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit(
         cirq.X(a),
@@ -109,7 +109,7 @@ def test_merge_single_qubit_gates_into_phxz():
     )
 
 
-def test_merge_single_qubit_gates_into_phxz_deep():
+def test_merge_single_qubit_gates_to_phxz_deep():
     a = cirq.NamedQubit("a")
     c_nested = cirq.FrozenCircuit(cirq.H(a), cirq.Z(a), cirq.H(a).with_tags("ignore"))
     c_nested_merged = cirq.FrozenCircuit(_phxz(-0.5, 0.5, 0).on(a), cirq.H(a).with_tags("ignore"))