1 # Copyright 2017 The TensorFlow Authors. All Rights Reserved. 2 # 3 # Licensed under the Apache License, Version 2.0 (the "License"); 4 # you may not use this file except in compliance with the License. 5 # You may obtain a copy of the License at 6 # 7 # http://www.apache.org/licenses/LICENSE-2.0 8 # 9 # Unless required by applicable law or agreed to in writing, software 10 # distributed under the License is distributed on an "AS IS" BASIS, 11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 # See the License for the specific language governing permissions and 13 # limitations under the License. 14 # ============================================================================== 15 """Miscellaneous utilities that don't fit anywhere else.""" 16 17 from __future__ import absolute_import 18 from __future__ import division 19 from __future__ import print_function 20 21 from tensorflow.python.framework import ops 22 from tensorflow.python.ops import array_ops 23 24 25 def alias_tensors(*args): 26 """Wrap any Tensor arguments with an identity op. 27 28 Any other argument, including Variables, is returned unchanged. 29 30 Args: 31 *args: Any arguments. Must contain at least one element. 32 33 Returns: 34 Same as *args, with Tensor instances replaced as described. 35 36 Raises: 37 ValueError: If args doesn't meet the requirements. 38 """ 39 40 def alias_if_tensor(a): 41 return array_ops.identity(a) if isinstance(a, ops.Tensor) else a 42 43 # TODO(mdan): Recurse into containers? 44 # TODO(mdan): Anything we can do about variables? Fake a scope reuse? 45 if len(args) > 1: 46 return (alias_if_tensor(a) for a in args) 47 elif len(args) == 1: 48 return alias_if_tensor(args[0]) 49 50 raise ValueError('at least one argument required') 51
