mirror of
https://github.com/facebook/sapling.git
synced 2024-10-12 17:58:27 +03:00
24 lines
530 B
Python
24 lines
530 B
Python
|
"""
|
||
|
|
Commonly useful converters.
|
||
|
|
"""
|
||
|
|
|
||
|
|
from __future__ import absolute_import, division, print_function
|
||
|
|
|
||
|
|
def optional(converter):
|
||
|
|
"""
|
||
|
|
A converter that allows an attribute to be optional. An optional attribute
|
||
|
|
is one which can be set to ``None``.
|
||
|
|
|
||
|
|
:param callable converter: the converter that is used for non-``None``
|
||
|
|
values.
|
||
|
|
|
||
|
|
.. versionadded:: 17.1.0
|
||
|
|
"""
|
||
|
|
|
||
|
|
def optional_converter(val):
|
||
|
|
if val is None:
|
||
|
|
return None
|
||
|
|
return converter(val)
|
||
|
|
|
||
|
|
return optional_converter
|