Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidGrep(3pm)
                                           User Contributed Perl Documentation


NAME
       Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidGrep - Don't use
       "grep" in void contexts.

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

DESCRIPTION
       "map" and "grep" are intended to be pure functions, not mutators.  If
       you want to iterate with side-effects, then you should use a proper
       "for" or "foreach" loop.

           grep{ print frobulate($_) } @list;           #not ok
           print map{ frobulate($_) } @list;            #ok

           grep{ $_ = lc $_ } @list;                    #not ok
           for( @list ){ $_ = lc $_  };                 #ok

           map{ push @frobbed, frobulate($_) } @list;   #not ok
           @frobbed = map { frobulate($_) } @list;      #ok

CONFIGURATION
       This Policy is not configurable except for the standard options.

AUTHOR
       Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>

COPYRIGHT
       Copyright (c) 2005-2011 Imaginative Software Systems.  All 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 v5.38.0                      2023-07-26
                 Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidGrep(3pm)