Fix pickling of tree_math.struct

PiperOrigin-RevId: 529802186

Author: shoyer

tree_math/_src/structs.py

@@ -1,3 +1,16 @@
+# Copyright 2021 Google LLC
+#
+# 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.
 """Helpers for constructing data classes that are JAX and tree-math enabled."""
 
 import dataclasses
@@ -62,5 +75,6 @@ def tree_unflatten(cls, _, children):
                         'asdict': asdict,
                         'astuple': astuple,
                         'tree_flatten': tree_flatten,
-                        'tree_unflatten': tree_unflatten})
+                        'tree_unflatten': tree_unflatten,
+                        '__module__': cls.__module__})
   return jax.tree_util.register_pytree_node_class(cls_as_struct)

tree_math/_src/structs_test.py

@@ -1,5 +1,17 @@
-"""Tests for global_circulation.structs."""
-
+# Copyright 2021 Google LLC
+#
+# 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.
+import pickle
 from typing import Union
 
 from absl.testing import absltest
@@ -10,6 +22,9 @@
 import numpy as np
 import tree_math
 
+from tree_math._src import test_util
+
+
 ArrayLike = Union[jnp.ndarray, np.ndarray, float]
 
 
@@ -19,7 +34,7 @@ class TestStruct:
   b: ArrayLike
 
 
-class StructsTest(parameterized.TestCase):
+class StructsTest(test_util.TestCase):
 
   @parameterized.named_parameters(
       dict(testcase_name='Scalars', x=TestStruct(1., 2.)),
@@ -89,6 +104,11 @@ def testJit(self, x, y, operation):
     np.testing.assert_allclose(jitted.a, unjitted.a)
     np.testing.assert_allclose(jitted.b, unjitted.b)
 
+  def testPickle(self):
+    struct = TestStruct(1, 2)
+    restored = pickle.loads(pickle.dumps(struct))
+    self.assertTreeEqual(struct, restored, check_dtypes=True)
+
 
 if __name__ == '__main__':
   absltest.main()