NAME

       RDF::Closure - pure Perl RDF inferencing

SYNOPSIS

        use RDF::Trine::Iterator qw[sgrep];
        use RDF::Closure qw[iri mk_filter FLT_NONRDF FLT_BORING];

        my $data = iri('http://bloggs.example.com/foaf.rdf');
        my $foaf = iri('http://xmlns.com/foaf/0.1/index.rdf');

        my $model = RDF::Trine::Model->temporary_model;
        my $p     = 'RDF::Trine::Parser';
        $p->parse_url_into_model($data->uri, $model, context => $data->uri);
        $p->parse_url_into_model($foaf->uri, $model, context => $foaf->uri);

        my $cl = RDF::Closure::Engine->new('rdfs', $model);
        $cl->closure;

        my $filter = mk_filter(FLT_NONRDF|FLT_BORING, [$foaf]);
        my $output = &sgrep($filter, $model->as_stream);

        print RDF::Trine::Serializer
          ->new('RDFXML')
          ->serialize_iterator_to_string($output);

DESCRIPTION

       This distribution is a pure Perl RDF inference engine designed as an add-in for
       RDF::Trine. It is largely a port of Ivan Herman's Python RDFClosure library, though there
       has been some restructuing, and there are a few extras thrown in.

       Where one of the Perl modules has a direct equivalent in Ivan's library, this is noted in
       the POD.

   Functions
       This package inherits from RDF::Trine and exports the same functions, plus:

       •   "mk_filter($basic_filters, $ignore_contexts)"

           Creates a filter (coderef) suitable for use with "sgrep" from RDF::Trine::Iterator.

           $basic_filters is an integer which can be assembled by bitwise-OR-ing the constants
           "FLT_NONRDF" and "FLT_BORING".

           $ignore_contexts is an arrayref of RDF::Trine::Node objects, each of which represents
           a context that should be filtered out.

             use RDF::Trine::Iterator qw[sgrep];
             use RDF::Closure qw[iri mk_filter FLT_NONRDF FLT_BORING];

             my $foaf   = iri('http://xmlns.com/foaf/0.1/index.rdf');
             my $filter = mk_filter(FLT_NONRDF|FLT_BORING, [$foaf]);

             my $remaining = &sgrep($filter, $model->as_stream);

             # $remaining is now an iterator which will return all triples
             # from $model except: those in the FOAF named graph, those which
             # are non-RDF (e.g. literal subject) and those which are boring.

           Which triples are boring? Any triple of the form { ?x owl:sameAs ?x .}, { ?x
           owl:equivalentProperty ?x .}, { ?x owl:equivalentClass ?x .}, { ?x rdfs:subPropertyOf
           ?x .} or { ?x rdfs:subClassOf ?x .} is boring (i.e. where these statements have the
           same term in subject and object position). Any triple where the subject, predicate and
           object nodes are all in the RDF, RDFS, OWL or XSD namespaces is boring. Other triples
           are not boring.

       For convenience, "RDF::Closure" also exports variables called $RDF, $RDFS, $OWL and $XSD
       which are RDF::Trine::Namespace objects.

SEE ALSO

       RDF::Closure::Engine, RDF::Closure::Model, RDF::Trine::Parser::OwlFn.

       RDF::Trine, RDF::Query.

       <http://www.perlrdf.org/>.

       http://www.ivan-herman.net/Misc/2008/owlrl/ <http://www.ivan-herman.net/Misc/2008/owlrl/>.

AUTHOR

       Toby Inkster <tobyink@cpan.org>.

COPYRIGHT

       Copyright 2011-2012 Toby Inkster

       This library is free software; you can redistribute it and/or modify it under any of the
       following licences:

       •   The Artistic License 1.0 <http://www.perlfoundation.org/artistic_license_1_0>.

       •   The GNU General Public License Version 1
           http://www.gnu.org/licenses/old-licenses/gpl-1.0.txt <http://www.gnu.org/licenses/old-
           licenses/gpl-1.0.txt>, or (at your option) any later version.

       •   The W3C Software Notice and License
           http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231
           <http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231>.

       •   The Clarified Artistic License <http://www.ncftp.com/ncftp/doc/LICENSE.txt>.

DISCLAIMER OF WARRANTIES

       THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
       WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
       PURPOSE.