Perl::Critic::Policy::RegularExpressions::ProhibitUselessTopic - Don't use $_ to match against regexes.

NAME  AFFILIATION  DESCRIPTION  CONFIGURATION  AUTHOR  COPYRIGHT 

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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 <[email protected]>

COPYRIGHT

Copyright (c) 2013−2023 Andy Lester <[email protected]>

This library is free software; you can redistribute it and/or modify it under the terms of the Artistic License 2.0.

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