Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/tensorflow/python/autograph/converters/slices.py: 29%

1# Copyright 2016 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"""Converter for slice operations.""" 

16 

17import gast 

18 

19from tensorflow.python.autograph.core import converter 

20from tensorflow.python.autograph.lang import directives 

21from tensorflow.python.autograph.pyct import templates 

22 

23 

24class SliceTransformer(converter.Base): 

25 """Converts slicing operations to their TF counterpart. 

26 

27 Currently, relying on the default slice operator that Tensor uses is 

28 insufficient, because TensorArray and tensor lists use dedicated index read 

29 and write functions. 

30 """ 

31 

32 def _process_single_assignment(self, target, value): 

33 if not isinstance(target, gast.Subscript): 

34 return None 

35 s = target.slice 

36 if isinstance(s, (gast.Tuple, gast.Slice)): 

37 return None 

38 

39 template = """ 

40 target = ag__.set_item(target, key, item) 

41 """ 

42 return templates.replace( 

43 template, target=target.value, key=target.slice, item=value) 

44 

45 def visit_Assign(self, node): 

46 node = self.generic_visit(node) 

47 # TODO(mdan): Support unpackings and multiple assignments. 

48 if len(node.targets) != 1: 

49 raise NotImplementedError('multiple assignment') 

50 replacement = self._process_single_assignment(node.targets[0], node.value) 

51 if replacement is not None: 

52 return replacement 

53 return node 

54 

55 def visit_Subscript(self, node): 

56 node = self.generic_visit(node) 

57 s = node.slice 

58 if isinstance(s, (gast.Tuple, gast.Slice)): 

59 return node 

60 

61 if not isinstance(node.ctx, gast.Load): 

62 # Index writes are handled at a higher level, one at which the rvalue is 

63 # also available. 

64 return node 

65 

66 dtype = self.get_definition_directive( 

67 node.value, 

68 directives.set_element_type, 

69 'dtype', 

70 default=templates.replace_as_expression('None')) 

71 

72 template = """ 

73 ag__.get_item( 

74 target, 

75 key, 

76 opts=ag__.GetItemOpts(element_dtype=dtype)) 

77 """ 

78 return templates.replace_as_expression( 

79 template, target=node.value, key=s, dtype=dtype) 

80 

81 

82def transform(node, ctx): 

83 return SliceTransformer(ctx).visit(node)