Perl::Critic::Policy::RegularExpressions::ProhibitSingleCharAlternation(3)
NAME
Perl::Critic::Policy::RegularExpressions::ProhibitSingleCharAlternation
- Use "[abc]" instead of "a|b|c".
AFFILIATION
This Policy is part of the core Perl::Critic distribution.
DESCRIPTION
Character classes (like "[abc]") are significantly faster than single
character alternations (like "(?:a|b|c)"). This policy complains if
you have more than one instance of a single character in an
alternation. So "(?:a|the)" is allowed, but "(?:a|e|i|o|u)" is not.
NOTE: Perl 5.10 (not released as of this writing) has major regexp
optimizations which may mitigate the performance penalty of
alternations, which will be rewritten behind the scenes as something
like character classes. Consequently, if you are deploying exclusively
on 5.10, yo might consider ignoring this policy.
CONFIGURATION
This Policy is not configurable except for the standard options.
CREDITS
Initial development of this policy was supported by a grant from the
Perl Foundation.
AUTHOR
Chris Dolan <cdolan@cpan.org>
COPYRIGHT
Copyright (c) 2007-2011 Chris Dolan. Many rights reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself. The full text of this license can
be found in the LICENSE file included with this module
perlPerl::Critic::Policy::RegularExpressions::ProhibitSingleCharAlternation(3)
perl-critic 1.134.0 - Generated Tue Jun 4 14:29:27 CDT 2019