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.