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ELLIOTJS / Perl-Critic-1.101_001 / lib / Perl / Critic / Policy / BuiltinFunctions / ProhibitVoidGrep.pm 

            

              
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##############################################################################
#      $URL: http://perlcritic.tigris.org/svn/perlcritic/branches/Perl-Critic-PPI-1.204/lib/Perl/Critic/Policy/BuiltinFunctions/ProhibitVoidGrep.pm $
#     $Date: 2009-07-21 08:50:56 -0700 (Tue, 21 Jul 2009) $
#   $Author: clonezone $
# $Revision: 3404 $
##############################################################################
package Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidGrep;
use 5.006001;
use strict;
use warnings;
use Readonly;
use Perl::Critic::Utils qw{ :severities :classification is_in_void_context };
use base 'Perl::Critic::Policy';
our $VERSION = '1.101_001';
#-----------------------------------------------------------------------------
Readonly::Scalar my $DESC => q{"grep" used in void context};
Readonly::Scalar my $EXPL => q{Use a "for" loop instead};
#-----------------------------------------------------------------------------
sub supported_parameters { return ()                     }
sub default_severity     { return $SEVERITY_MEDIUM       }
sub default_themes       { return qw( core maintenance ) }
sub applies_to           { return 'PPI::Token::Word'     }
#-----------------------------------------------------------------------------
sub violates {
    my ( $self, $elem, undef ) = @_;
    return if $elem ne 'grep';
    return if not is_function_call($elem);
    return if not is_in_void_context($elem);
    return $self->violation( $DESC, $EXPL, $elem );
}
1;
__END__
#-----------------------------------------------------------------------------
=pod
=head1 NAME
Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidGrep - Don't use C<grep> in void contexts.
=head1 AFFILIATION
This Policy is part of the core L<Perl::Critic|Perl::Critic>
distribution.
=head1 DESCRIPTION
C<map> and C<grep> are intended to be pure functions, not mutators.
If you want to iterate with side-effects, then you should use a proper
C<for> or C<foreach> loop.
    grep{ print frobulate($_) } @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
=head1 CONFIGURATION
This Policy is not configurable except for the standard options.
=head1 AUTHOR
Jeffrey Ryan Thalhammer <thaljef@cpan.org>
=head1 COPYRIGHT
Copyright (c) 2005-2009 Jeffrey Ryan Thalhammer.  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.
=cut
# Local Variables:
#   mode: cperl
#   cperl-indent-level: 4
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# End:
# ex: set ts=8 sts=4 sw=4 tw=78 ft=perl expandtab shiftround :