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GWILLIAMS / RDF-Trine-1.007_01 / lib / RDF / Trine / Node / Variable.pm 

            

              
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# RDF::Trine::Node::Variable
# -----------------------------------------------------------------------------
=head1 NAME
RDF::Trine::Node::Variable - RDF Node class for variables
=head1 VERSION
This document describes RDF::Trine::Node::Variable version 1.007_01
=cut
package RDF::Trine::Node::Variable;
use strict;
use warnings;
no warnings 'redefine';
use base qw(RDF::Trine::Node);
use Data::Dumper;
use Scalar::Util qw(blessed);
use Carp qw(carp croak confess);
######################################################################
our ($VERSION);
BEGIN {
        $VERSION        = '1.007_01';
}
######################################################################
use overload    '""'    => sub { $_[0]->sse },
                        ;
=head1 METHODS
Beyond the methods documented below, this class inherits methods from the
L<RDF::Trine::Node> class.
=over 4
=cut
=item C<new ( $name )>
Returns a new Variable structure.
=cut
sub new {
        my $class       = shift;
        my $name        = shift;
        return bless( [ $name ], $class );
}
=item C<< name >>
Returns the name of the variable.
=cut
sub name {
        my $self        = shift;
        return $self->[0];
}
=item C<< sse >>
Returns the SSE string for this variable.
=cut
sub sse {
        my $self        = shift;
        my $name        = $self->name;
        return qq(?${name});
}
=item C<< as_string >>
Returns a string representation of the node.
=cut
sub as_string {
        my $self        = shift;
        return '?' . $self->name;
}
=item C<< value >>
Returns the variable name.
=cut
sub value {
        my $self        = shift;
        return $self->name;
}
=item C<< as_ntriples >>
Returns the node in a string form suitable for NTriples serialization.
=cut
sub as_ntriples {
        my $self        = shift;
        throw RDF::Trine::Error::UnimplementedError -text => "Variable nodes aren't allowed in NTriples";
}
=item C<< type >>
Returns the type string of this node.
=cut
sub type {
        return 'VAR';
}
=item C<< equal ( $node ) >>
Returns true if the two nodes are equal, false otherwise.
=cut
sub equal {
        my $self        = shift;
        my $node        = shift;
        return 0 unless (blessed($node) and $node->isa('RDF::Trine::Node'));
        return 0 unless ($self->type eq $node->type);
        return ($self->name eq $node->name);
}
# called to compare two nodes of the same type
sub _compare {
        my $a   = shift;
        my $b   = shift;
        return ($a->name cmp $b->name);
}
1;
__END__
=back
=head1 BUGS
Please report any bugs or feature requests to through the GitHub web interface
at L<https://github.com/kasei/perlrdf/issues>.
=head1 AUTHOR
Gregory Todd Williams  C<< <gwilliams@cpan.org> >>
=head1 COPYRIGHT
Copyright (c) 2006-2012 Gregory Todd Williams. This
program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.
=cut