Perl::Critic::Policy::Variables::RequireInitializationForLocalVars - Write C<local $foo = $bar;> instead of just C<local $foo;>.

Perl-Critic documentation Contained in the Perl-Critic distribution.

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NAME

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Perl::Critic::Policy::Variables::RequireInitializationForLocalVars - Write local $foo = $bar; instead of just local $foo;.

AFFILIATION

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

DESCRIPTION

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Most people don't realize that a localized copy of a variable does not retain its original value. Unless you initialize the variable when you local-ize it, it defaults to undef. If you want the variable to retain its original value, just initialize it to itself. If you really do want the localized copy to be undef, then make it explicit.

    package Foo;
    $Bar = '42';

    package Baz;

    sub frobulate {

        local $Foo::Bar;              #not ok, local $Foo::Bar is 'undef'
        local $Foo::Bar = undef;      #ok, local $Foo::Bar is obviously 'undef'
        local $Foo::Bar = $Foo::Bar;  #ok, local $Foo::Bar still equals '42'

    }

CONFIGURATION

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This Policy is not configurable except for the standard options.

AUTHOR

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

COPYRIGHT

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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-Critic documentation Contained in the Perl-Critic distribution. 
##############################################################################
#      $URL: http://perlcritic.tigris.org/svn/perlcritic/trunk/distributions/Perl-Critic/lib/Perl/Critic/Policy/Variables/RequireInitializationForLocalVars.pm $
#     $Date: 2011-05-15 16:34:46 -0500 (Sun, 15 May 2011) $
#   $Author: clonezone $
# $Revision: 4078 $
##############################################################################

package Perl::Critic::Policy::Variables::RequireInitializationForLocalVars;

use 5.006001;
use strict;
use warnings;
use Readonly;

use Perl::Critic::Utils qw{ :severities };
use base 'Perl::Critic::Policy';

our $VERSION = '1.116';

#-----------------------------------------------------------------------------

Readonly::Scalar my $DESC => q{"local" variable not initialized};
Readonly::Scalar my $EXPL => [ 78 ];

#-----------------------------------------------------------------------------

sub supported_parameters { return ()                         }
sub default_severity     { return $SEVERITY_MEDIUM           }
sub default_themes       { return qw(core pbp bugs)          }
sub applies_to           { return 'PPI::Statement::Variable' }

#-----------------------------------------------------------------------------

sub violates {
    my ( $self, $elem, undef ) = @_;
    if ( $elem->type() eq 'local' && !_is_initialized($elem) ) {
        return $self->violation( $DESC, $EXPL, $elem );
    }
    return;    #ok!
}

#-----------------------------------------------------------------------------

sub _is_initialized {
    my $elem = shift;
    my $wanted = sub { $_[1]->isa('PPI::Token::Operator') && $_[1] eq q{=} };
    return $elem->find( $wanted ) ? 1 : 0;
}

1;

__END__

#-----------------------------------------------------------------------------


# 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 :