Perl::Critic::Policy::BuiltinFunctions::ProhibitBooleanGrep - Use any from List::Util, List::SomeUtils, or List::MoreUtils instead of grep in boolean context.
This Policy is part of the core Perl::Critic distribution.
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.
This Policy is not configurable except for the standard options.
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.
Chris Dolan <cdolan@cpan.org>
Initial development of this policy was supported by a grant from the Perl Foundation.
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.