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.

perl v5.36.0                     Perl::Critic::Policy::BuiltinFunctions::ProhibitBooleanGrep(3pm)