| # Copyright 2019 DeepMind Technologies Limited. All Rights Reserved. | |
| # | |
| # 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 | |
| # | |
| # http://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. | |
| # ============================================================================== | |
| """Utilities to cast pytrees to specific dtypes.""" | |
| from typing import Optional | |
| import chex | |
| from jax import tree_util as jtu | |
| def tree_cast( | |
| tree: chex.ArrayTree, | |
| dtype: Optional[chex.ArrayDType] | |
| ) -> chex.ArrayTree: | |
| """Cast tree to given dtype, skip if None.""" | |
| if dtype is not None: | |
| return jtu.tree_map(lambda t: t.astype(dtype), tree) | |
| else: | |
| return tree | |