RDF::Trine::VariableBindings - Variable bindings
This document describes RDF::Trine::VariableBindings version 1.019
use RDF::Trine qw(literal); use RDF::Trine::VariableBindings; my $vb = RDF::Trine::VariableBindings->new( {} ); $vb->set( foo => literal("bar") ); $vb->set( baz => literal("blee") ); $vb->variables; # qw(foo baz) my $x = RDF::Trine::VariableBindings->new( { foo => literal("bar") } ); $x->set( greeting => literal("hello") ); my $j = $vb->join( $x ); # { foo => "bar", baz => "blee", greeting => "hello" } my @keys = qw(baz greeting); my $p = $j->project( @keys ); # { baz => "blee", greeting => "hello" } print $p->{greeting}->literal_value; # "hello"
RDF::Trine::VariableBindings objects provide a mapping from variable names to RDF::Trine::Node objects. The objects may be used as a hash reference, with variable names used as hash keys.
new ( \%bindings )
set ( $variable_name => $node )
join ( $row )
Returns a new VariableBindings object based on the join of this object and $row. If the two variable binding objects cannot be joined, returns undef.
$row
variables
project ( @keys )
Returns a new binding with values for only the keys listed.
as_string
Returns a string representation of the variable bindings.
label ( $label => $value )
Sets the named $label to $value for this variable bindings object. If no $value is given, returns the current label value, or undef if none exists.
$label
$value
copy_labels_from ( $vb )
Copies the labels from $vb, adding them to the labels for this object.
$vb
Please report any bugs or feature requests to through the GitHub web interface at https://github.com/kasei/perlrdf/issues.
Gregory Todd Williams <gwilliams@cpan.org>
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.
To install RDF::Trine, copy and paste the appropriate command in to your terminal.
cpanm
cpanm RDF::Trine
CPAN shell
perl -MCPAN -e shell install RDF::Trine
For more information on module installation, please visit the detailed CPAN module installation guide.