Perl::Critic::Policy::Plicease::ProhibitUnicodeDigitInRegexp - Prohibit non-ASCII \d in regular expressions
The character class
\d in a regular expression matches all unicode digit character, which might not be what you expect if you are testing if a string can be used as a number in Perl. Instead use either
[0-9], or if you are on Perl 5.14 or better you can use the
/a modifier. This policy allows
\d in expressions with an explicit
/u modifier (normally on by default), as it indicates that the code is expecting Unicode semantics, including Unicode digits.
/\d/; # not ok /\d/a; # ok /\d/u; # ok /[0-9]/; # ok
This policy is not configurable except for the standard options.
This is not a general policy, and should not be applied toward all applications without some thought. This is frequently true for Perl::Critic policies, but especially so for this policy.
In the general the ability to match against unicode digits is a useful ability, and doesn't constitute bad code. Some applications don't ever need to match non-ASCII digit characters, and incorrectly rely on
\d to validate as a number.
This policy doesn't take into account using the re pragma.
use re '/a'; /\d/; # (still) not ok
Graham Ollis <email@example.com>
This software is copyright (c) 2019 by Graham Ollis.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.