Perl::Critic::Policy::RegularExpressions::ProhibitUselessTopic(3)
NAME
Perl::Critic::Policy::RegularExpressions::ProhibitUselessTopic - Don't
use $_ to match against regexes.
AFFILIATION
This Policy is part of the Perl::Critic distribution.
DESCRIPTION
It is not necessary to specify the topic variable $_ when matching
against a regular expression.
Match or substitution operations are performed against variables, such
as:
$x =~ /foo/;
$x =~ s/foo/bar/;
$x =~ tr/a-mn-z/n-za-m/;
If a variable is not specified, the match is against $_.
# These are identical.
/foo/;
$_ =~ /foo/;
# These are identical.
s/foo/bar/;
$_ =~ s/foo/bar/;
# These are identical.
tr/a-mn-z/n-za-m/;
$_ =~ tr/a-mn-z/n-za-m/;
This applies to negative matching as well.
# These are identical
if ( $_ !~ /DEBUG/ ) { ...
if ( !/DEBUG ) { ...
Including the "$_ =~" or "$_ !~" is unnecessary, adds complexity, and
is not idiomatic Perl.
CONFIGURATION
This Policy is not configurable except for the standard options.
AUTHOR
Andy Lester <andy@petdance.com>
COPYRIGHT
Copyright (c) 2013 Andy Lester <andy@petdance.com>
This library is free software; you can redistribute it and/or modify it
under the terms of the Artistic License 2.0.
perl v5.28.2 Perl::Critic::Policy::RegularExpressions::ProhibitUselessTopic(3)
perl-critic 1.134.0 - Generated Tue Jun 4 14:31:55 CDT 2019