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ELLIOTJS / Perl-Critic-1.099_002 / lib / Perl / Critic / Policy / Variables / RequireLexicalLoopIterators.pm 

            

              
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##############################################################################
#      $URL: http://perlcritic.tigris.org/svn/perlcritic/trunk/distributions/Perl-Critic/lib/Perl/Critic/Policy/Variables/RequireLexicalLoopIterators.pm $
#     $Date: 2009-06-27 20:02:58 -0400 (Sat, 27 Jun 2009) $
#   $Author: clonezone $
# $Revision: 3373 $
##############################################################################
package Perl::Critic::Policy::Variables::RequireLexicalLoopIterators;
use 5.006001;
use strict;
use warnings;
use Readonly;
use Perl::Critic::Utils qw{ :severities };
use base 'Perl::Critic::Policy';
our $VERSION = '1.099_002';
#-----------------------------------------------------------------------------
Readonly::Scalar my $DESC => q{Loop iterator is not lexical};
Readonly::Scalar my $EXPL => [ 108 ];
#-----------------------------------------------------------------------------
sub supported_parameters { return ()                         }
sub default_severity     { return $SEVERITY_HIGHEST          }
sub default_themes       { return qw(core pbp bugs)          }
sub applies_to           { return 'PPI::Statement::Compound' }
#-----------------------------------------------------------------------------
sub violates {
    my ( $self, $elem, undef ) = @_;
    # First child will be 'for' or 'foreach' keyword
    my $first_child = $elem->schild(0);
    return if !$first_child;
    return if $first_child ne 'for' and $first_child ne 'foreach';
    # The second child could be the iteration list
    my $second_child = $elem->schild(1);
    return if !$second_child;
    return if $second_child->isa('PPI::Structure::ForLoop');
    return if $second_child->content() eq 'my';
    return $self->violation( $DESC, $EXPL, $elem );
}
#-----------------------------------------------------------------------------
1;
__END__
#-----------------------------------------------------------------------------
=pod
=head1 NAME
Perl::Critic::Policy::Variables::RequireLexicalLoopIterators - Write C<for my $element (@list) {...}> instead of C<for $element (@list) {...}>.
=head1 AFFILIATION
This Policy is part of the core L<Perl::Critic|Perl::Critic>
distribution.
=head1 DESCRIPTION
C<for>/C<foreach> loops I<always> create new lexical variables for
named iterators.  In other words
    for $zed (...) {
        ...
    }
is equivalent to
    for my $zed (...) {
        ...
    }
This may not seem like a big deal until you see code like
    my $bicycle;
    for $bicycle (@things_attached_to_the_bike_rack) {
        if (
                $bicycle->is_red()
            and $bicycle->has_baseball_card_in_spokes()
            and $bicycle->has_bent_kickstand()
        ) {
            $bicycle->remove_lock();
            last;
        }
    }
    if ( $bicycle and $bicycle->is_unlocked() ) {
        ride_home($bicycle);
    }
which is not going to allow you to arrive in time for dinner with your
family because the C<$bicycle> outside the loop is different from the
C<$bicycle> inside the loop.  You may have freed your bicycle, but you
can't remember which one it was.
=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
#   fill-column: 78
#   indent-tabs-mode: nil
#   c-indentation-style: bsd
# End:
# ex: set ts=8 sts=4 sw=4 tw=78 ft=perl expandtab shiftround :