NAME

       RDF::Trine::Node::Formula - RDF Node class for formulae / graph literals

DESCRIPTION

       Formulae are implemented as a subclass of literals. Parts of Trine that have no special knowledge about
       formulae (e.g. the Turtle serialiser) will just see them as literals with a particular datatype URI
       (http://open.vocab.org/terms/Formula).

       If your code needs to detect formulae nodes, try:

         use Scalar::Util qw[blessed];
         if (blessed($node) && $node->isa('RDF::Trine::Node::Formula'))
           { ... do stuff to formulae ... }

       or perhaps

         use Scalar::Util qw[blessed];
         if (blessed($node) && $node->can('pattern'))
           { ... do stuff to formulae ... }

Constructor

       "new ( $pattern )"
           Returns a new Formula structure. This is a subclass of RDF::Trine::Node::Literal.

           $pattern    is    an    RDF::Trine::Pattern    or   a   string   capable   of   being   parsed   with
           RDF::Trine::Parser::Notation3->parse_formula.

Methods

       "pattern ( $node )"
           Returns the formula as an RDF::Trine::Pattern.

       "forAll"
           Returns the a list of nodes with the @forAll quantifier.

           This is a fairly obscure bit of N3 semantics.

       "forSome"
           Returns the a list of nodes with the @forSome quantifier.

           This is a fairly obscure bit of N3 semantics.

       "as_literal_notation"
           Returns the formula in Notation-3-like syntax, excluding the wrapping "{"..."}".

           Uses absolute URIs whenever possible, avoiding relative URI references, QNames and keywords.

       "from_literal_notation ( $string, $base )"
           Modifies the formula's value using Notation 3 syntax, excluding the wrapping "{"..."}".

       "equal ( $node )"
           Returns true if the two nodes are equal, false otherwise.

           TODO - really need a "not equal, but equivalent" method.

BUGS

       Please report any bugs to <http://rt.cpan.org/Dist/Display.html?Queue=RDF-TriN3>.

SEE ALSO

       RDF::Trine::Node, RDF::Trine::Pattern.

AUTHOR

       Toby Inkster  "<tobyink@cpan.org>"

       Based on RDF::Trine::Node::Literal by Gregory Todd Williams.

COPYRIGHT AND LICENCE

       Copyright (c) 2006-2010 Gregory Todd Williams.

       Copyright (c) 2010-2012 Toby Inkster.

       This library is free software; you can redistribute it and/or modify it under  the  same  terms  as  Perl
       itself.

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.

perl v5.34.0                                       2022-06-17                     RDF::Trine::Node::Formula(3pm)