Mercurial > hg
view mercurial/thirdparty/attr/converters.py @ 40959:d097dd0afc19
rust: translation of missingancestors
This is as direct as possible a translation of the ancestor.missingancestors
Python class in pure Rust. The goal for this changeset is to make it easy
to compare with the Python version.
We also add to Python tests the cases that helped us develop and debug
this implementation.
Some possible optimizations are marked along the way as TODO comments
Differential Revision: https://phab.mercurial-scm.org/D5416
author | Georges Racinet <gracinet@anybox.fr> |
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date | Fri, 30 Nov 2018 00:46:55 +0100 |
parents | 765eb17a7eb8 |
children | e1c586b9a43c |
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""" 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