Coverage for sources/absence/installers.py: 100%

1# vim: set filetype=python fileencoding=utf-8: 

2# -*- coding: utf-8 -*- 

3 

4#============================================================================# 

5# # 

6# Licensed under the Apache License, Version 2.0 (the "License"); # 

7# you may not use this file except in compliance with the License. # 

8# You may obtain a copy of the License at # 

9# # 

10# http://www.apache.org/licenses/LICENSE-2.0 # 

11# # 

12# Unless required by applicable law or agreed to in writing, software # 

13# distributed under the License is distributed on an "AS IS" BASIS, # 

14# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # 

15# See the License for the specific language governing permissions and # 

16# limitations under the License. # 

17# # 

18#============================================================================# 

19 

20 

21''' Convenience to expose global sentinel and sentinel checker in builtins. ''' 

22 

23 

24from . import __ 

25 

26 

27def install( 

28 sentinel_name: __.typx.Annotated[ 

29 str | None, 

30 __.ddoc.Doc( 

31 ''' Name to use for sentinel in builtins. ``None`` to skip. ''' ) 

32 ] = 'Absent', # Follows builtins convention: Ellipsis, None, NotImplemented 

33 predicate_name: __.typx.Annotated[ 

34 str | None, 

35 __.ddoc.Doc( 

36 ''' Name to use for predicate in builtins. ``None`` to skip. ''' ) 

37 ] = 'isabsent', # Follows builtins convention: isinstance, issubclass 

38) -> None: 

39 ''' Installs absence sentinel and predicate as builtins. ''' 

40 builtins = __import__( 'builtins' ) 

41 from .objects import absent, is_absent 

42 if sentinel_name: setattr( builtins, sentinel_name, absent ) 

43 if predicate_name: setattr( builtins, predicate_name, is_absent )