/ 
Perl-Critic-1.156
River stage three • 131 direct dependents • 411 total dependents
/ Perl::Critic::Policy::BuiltinFunctions::ProhibitBooleanGrep

NAME

Perl::Critic::Policy::BuiltinFunctions::ProhibitBooleanGrep - Use any from List::Util, List::SomeUtils, or List::MoreUtils instead of grep in boolean context.

AFFILIATION

This Policy is part of the core Perl::Critic distribution.

DESCRIPTION

Using grep in boolean context is a common idiom for checking if any elements in a list match a condition. This works because boolean context is a subset of scalar context, and grep returns the number of matches in scalar context. A non-zero number of matches means a match.

But consider the case of a long array where the first element is a match. Boolean grep still checks all of the rest of the elements needlessly. Instead, a better solution is to use the any function from either List::Util, List::SomeUtils, or List::MoreUtils. The any function will return as soon as a successful match is found, rather than processing the entire list. This saves time.

CONFIGURATION

This Policy is not configurable except for the standard options.

CAVEATS

The algorithm for detecting boolean context takes a LOT of shortcuts. There are lots of known false negatives. But, I was conservative in writing this, so I hope there are no false positives.

AUTHOR

Chris Dolan <cdolan@cpan.org>

CREDITS

Initial development of this policy was supported by a grant from the Perl Foundation.

COPYRIGHT

Copyright (c) 2007-2021 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.