Deprecate json_serializable_dataclass (#5208)

Fixes #4460

Author: maffoo

Diff for: cirq-core/cirq/experiments/cross_entropy_benchmarking.py

@@ -98,7 +98,7 @@ def purity(self) -> float:
         return self.cycle_depolarization**2
 
 
-@protocols.json_serializable_dataclass(frozen=True)
+@dataclasses.dataclass(frozen=True)
 class CrossEntropyResult:
     """Results from a cross-entropy benchmarking (XEB) experiment.
 
@@ -208,6 +208,9 @@ def _from_json_dict_(cls, data, repetitions, **kwargs):
             purity_data=purity_data,
         )
 
+    def _json_dict_(self):
+        return protocols.dataclass_json_dict(self)
+
     def __repr__(self) -> str:
         args = f'data={[tuple(p) for p in self.data]!r}, repetitions={self.repetitions!r}'
         if self.purity_data is not None:

Diff for: cirq-core/cirq/experiments/grid_parallel_two_qubit_xeb.py

@@ -20,7 +20,7 @@
 by executing circuits that act on many pairs simultaneously.
 """
 
-from typing import Any, Iterable, List, Optional, Sequence, TYPE_CHECKING, Tuple, cast
+from typing import Any, Dict, Iterable, List, Optional, Sequence, TYPE_CHECKING, Tuple, cast
 import collections
 from concurrent.futures import ThreadPoolExecutor
 import dataclasses
@@ -46,7 +46,6 @@
 )
 
 if TYPE_CHECKING:
-    from typing import Dict
     import cirq
 
 DEFAULT_BASE_DIR = os.path.expanduser(
@@ -101,22 +100,25 @@ def load(params: Any, base_dir: str) -> Any:
     return protocols.read_json(filename)
 
 
-@protocols.json_serializable_dataclass
+@dataclasses.dataclass
 class GridParallelXEBMetadata:
     """Metadata for a grid parallel XEB experiment.
 
     Attributes:
         data_collection_id: The data collection ID of the experiment.
     """
 
-    qubits: List['cirq.Qid']
+    qubits: Sequence['cirq.Qid']
     two_qubit_gate: 'cirq.Gate'
     num_circuits: int
     repetitions: int
-    cycles: List[int]
-    layers: List[GridInteractionLayer]
+    cycles: Sequence[int]
+    layers: Sequence[GridInteractionLayer]
     seed: Optional[int]
 
+    def _json_dict_(self):
+        return protocols.dataclass_json_dict(self)
+
     def __repr__(self) -> str:
         return (
             'cirq.experiments.grid_parallel_two_qubit_xeb.'

Diff for: cirq-core/cirq/protocols/json_serialization.py

@@ -39,7 +39,7 @@
 import sympy
 from typing_extensions import Protocol
 
-from cirq._compat import deprecated_parameter
+from cirq._compat import deprecated, deprecated_parameter
 from cirq._doc import doc_private
 from cirq.type_workarounds import NotImplementedType
 
@@ -190,6 +190,7 @@ class name via a dot (.)
 
 # Copying the Python API, whose usage of `repr` annoys pylint.
 # pylint: disable=redefined-builtin
+@deprecated(deadline='v0.15', fix='Implement _json_dict_ using cirq.dataclass_json_dict()')
 def json_serializable_dataclass(
     _cls: Optional[Type] = None,
     *,

Diff for: cirq-core/cirq/protocols/json_serialization_test.py

@@ -855,10 +855,14 @@ def test_pathlib_paths(tmpdir):
 
 
 def test_json_serializable_dataclass():
-    @cirq.json_serializable_dataclass
-    class MyDC:
-        q: cirq.LineQubit
-        desc: str
+    with cirq.testing.assert_deprecated(
+        "Implement _json_dict_ using cirq.dataclass_json_dict()", deadline="v0.15"
+    ):
+
+        @cirq.json_serializable_dataclass
+        class MyDC:
+            q: cirq.LineQubit
+            desc: str
 
     my_dc = MyDC(cirq.LineQubit(4), 'hi mom')
 
@@ -885,10 +889,14 @@ def custom_resolver(name):
 
 
 def test_json_serializable_dataclass_parenthesis():
-    @cirq.json_serializable_dataclass()
-    class MyDC:
-        q: cirq.LineQubit
-        desc: str
+    with cirq.testing.assert_deprecated(
+        "Implement _json_dict_ using cirq.dataclass_json_dict()", deadline="v0.15"
+    ):
+
+        @cirq.json_serializable_dataclass()
+        class MyDC:
+            q: cirq.LineQubit
+            desc: str
 
     def custom_resolver(name):
         if name == 'MyDC':
@@ -918,11 +926,15 @@ def custom_resolver(name):
 
 
 def test_json_serializable_dataclass_namespace():
-    @cirq.json_serializable_dataclass(namespace='cirq.experiments')
-    class QuantumVolumeParams:
-        width: int
-        depth: int
-        circuit_i: int
+    with cirq.testing.assert_deprecated(
+        "Implement _json_dict_ using cirq.dataclass_json_dict()", deadline="v0.15"
+    ):
+
+        @cirq.json_serializable_dataclass(namespace='cirq.experiments')
+        class QuantumVolumeParams:
+            width: int
+            depth: int
+            circuit_i: int
 
     qvp = QuantumVolumeParams(width=5, depth=5, circuit_i=0)
 

Diff for: cirq-google/cirq_google/calibration/phased_fsim.py

@@ -47,11 +47,6 @@
 if TYPE_CHECKING:
     import cirq_google
 
-    # Workaround for mypy custom dataclasses (python/mypy#5406)
-    from dataclasses import dataclass as json_serializable_dataclass
-else:
-    from cirq.protocols import json_serializable_dataclass
-
 
 _FLOQUET_PHASED_FSIM_HANDLER_NAME = 'floquet_phased_fsim_characterization'
 _XEB_PHASED_FSIM_HANDLER_NAME = 'xeb_phased_fsim_characterization'
@@ -94,7 +89,7 @@ def _create_pairs_from_moment(
     return tuple(pairs), gate
 
 
-@json_serializable_dataclass(frozen=True)
+@dataclasses.dataclass(frozen=True)
 class PhasedFSimCharacterization:
     """Holder for the unitary angles of the cirq.PhasedFSimGate.
 
@@ -202,6 +197,9 @@ def override_by(self, other: 'PhasedFSimCharacterization') -> 'PhasedFSimCharact
         """
         return other.merge_with(self)
 
+    def _json_dict_(self):
+        return cirq.dataclass_json_dict(self)
+
 
 SQRT_ISWAP_INV_PARAMETERS = PhasedFSimCharacterization(
     theta=np.pi / 4, zeta=0.0, chi=0.0, gamma=0.0, phi=0.0
@@ -429,7 +427,7 @@ def parse_result(
         """Decodes the characterization result issued for this request."""
 
 
-@json_serializable_dataclass(frozen=True)
+@dataclasses.dataclass(frozen=True)
 class XEBPhasedFSimCalibrationOptions(PhasedFSimCalibrationOptions):
     """Options for configuring a PhasedFSim calibration using XEB.
 
@@ -496,8 +494,11 @@ def _from_json_dict_(cls, **kwargs):
         kwargs['cycle_depths'] = tuple(kwargs['cycle_depths'])
         return cls(**kwargs)
 
+    def _json_dict_(self):
+        return cirq.dataclass_json_dict(self)
 
-@json_serializable_dataclass(frozen=True)
+
+@dataclasses.dataclass(frozen=True)
 class LocalXEBPhasedFSimCalibrationOptions(XEBPhasedFSimCalibrationOptions):
     """Options for configuring a PhasedFSim calibration using a local version of XEB.
 
@@ -542,8 +543,11 @@ def create_phased_fsim_request(
     ):
         return LocalXEBPhasedFSimCalibrationRequest(pairs=pairs, gate=gate, options=self)
 
+    def _json_dict_(self):
+        return cirq.dataclass_json_dict(self)
+
 
-@json_serializable_dataclass(frozen=True)
+@dataclasses.dataclass(frozen=True)
 class FloquetPhasedFSimCalibrationOptions(PhasedFSimCalibrationOptions):
     """Options specific to Floquet PhasedFSimCalibration.
 
@@ -590,6 +594,9 @@ def create_phased_fsim_request(
     ) -> 'FloquetPhasedFSimCalibrationRequest':
         return FloquetPhasedFSimCalibrationRequest(pairs=pairs, gate=gate, options=self)
 
+    def _json_dict_(self):
+        return cirq.dataclass_json_dict(self)
+
 
 """Floquet PhasedFSimCalibrationOptions options with all angles characterization requests set to
 True."""
@@ -821,7 +828,7 @@ def _parse_characterized_angles(
     return dict(records)
 
 
-@json_serializable_dataclass(frozen=True)
+@dataclasses.dataclass(frozen=True)
 class LocalXEBPhasedFSimCalibrationRequest(PhasedFSimCalibrationRequest):
     """PhasedFSim characterization request for local cross entropy benchmarking (XEB) calibration.
 
@@ -856,8 +863,11 @@ def _from_json_dict_(
         instantiation_pairs = tuple((q_a, q_b) for q_a, q_b in pairs)
         return cls(instantiation_pairs, gate, options)
 
+    def _json_dict_(self):
+        return cirq.dataclass_json_dict(self)
 
-@json_serializable_dataclass(frozen=True)
+
+@dataclasses.dataclass(frozen=True)
 class XEBPhasedFSimCalibrationRequest(PhasedFSimCalibrationRequest):
     """PhasedFSim characterization request for cross entropy benchmarking (XEB) calibration.
 
@@ -915,6 +925,9 @@ def _from_json_dict_(
         instantiation_pairs = tuple((q_a, q_b) for q_a, q_b in pairs)
         return cls(instantiation_pairs, gate, options)
 
+    def _json_dict_(self):
+        return cirq.dataclass_json_dict(self)
+
 
 class IncompatibleMomentError(Exception):
     """Error that occurs when a moment is not supported by a calibration routine."""