# Redland RDF Application Framework - Perl RDF::Redland::Iterator Class

## NAME

RDF::Redland::Iterator - Redland RDF Iterator Class

## SYNOPSIS

      use RDF::Redland;

      ...
      my $iterator=$model->targets_iterator($source_node, $arc_node);
      while($iterator && !$iterator->end) {
        my $node=$iterator->current;
        ...
        $iterator->next;
      }

## DESCRIPTION

This class is used to return lists of RDF::Redland::Node objects from a method that returns an RDF::Redland::Iterator - commonly one of the get_sources_iterator, get_targets_iterator or get_arcs_iterator methods of the RDF::Redland::Model class.

This allows efficient retrieval of long lists of RDF::Redland::Node objects but isn't really very Perl-friendly. The get_sources, get_targets or get_arcs methods of RDF::Redland::Model class return Perl lists and the get_source, get_target and get_arc methods return single arbitrary results.

## CONSTRUCTORS

No public constructors - are created and returned from various methods of classes including RDF::Redland::Model

## METHODS

end
  Return non 0 if the iterator has finished
current
  Returns the current RDF::Redland::Node object from the iteration or undef if the iteration is finished.
next
  Moves the iterator to the next item, returns undef if the iteration is finished.
context
  Returns the context RDF::Redland::Node object from the iteration or undef if the iteration is finished.

## SEE ALSO

the RDF::Redland::Model manpage and the RDF::Redland::Node manpage

## AUTHOR

Dave Beckett - http://purl.org/net/dajobe/

Copyright 2000-2003 Dave Beckett, Institute for Learning and Research Technology, University of Bristol