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 __future__ import annotations 

25 

26from . import __ 

27 

28 

29def install( 

30 sentinel_name: __.typx.Annotated[ 

31 str | None, 

32 __.dynadoc.Doc( 

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

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

35 predicate_name: __.typx.Annotated[ 

36 str | None, 

37 __.dynadoc.Doc( 

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

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

40) -> None: 

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

42 builtins = __import__( 'builtins' ) 

43 from .objects import absent, is_absent 

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

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