SIMPLE SOLUTIONS

RDF::CLOSURE::DATATYPEHANDLING - reference manual online

Validate and canonicalise typed literals.

Chapter
2012-06-28
RDF::Closure::DatatypeHandling(User Contributed Perl DocumentaRDF::Closure::DatatypeHandling(3pm)

NAME RDF::Closure::DatatypeHandling - validate and canonicalise typed literals
ANALOGOUS PYTHON RDFClosure/DatatypeHandling.py
DESCRIPTION Provides datatype handling functions for OWL 2 RL and RDFS datatypes. Functional Interface This module can export four functions: · "literal_canonical($lit)" Given an RDF::Trine::Node::Literal, returns a literal with the canonical lexical value for its given datatype. If the literal is not a valid lexical form for its datatype throws an Error. If the literal is a plain literal, returns an rdf:PlainLiteral typed literal; if the literal is of an unrecognised datatype, simply returns the original literal. Note that as per OWL 2 RL rules, xsd:dateTime literals are not shifted to UTC, even though XSD says that UTC is the canonical form. By setting the "force_utc" to true, you can force XSD-style canonicalisation. (See the object-oriented interface.) · "literal_canonical_safe($lit)" As per "literal_canonical", but in the case where a literal is not a valid lexical form, simply returns the original literal. · "literal_valid($lit)" Returns true iff the literal is a valid lexical form for its datatype. An example of an invalid literal might be: "2011-02-29"^^xsd:date · "literals_identical($lit1, $lit2)" Returns true iff the two literals are identical according to OWL 2 RL. Here are some example pairs that are identical: # integers and decimals are drawn from the same pool of values "1.000"^^xsd:decimal "1"^^xsd:integer # different ways of writing the same datetime "2010-01-01T12:00:00.000Z"^^xsd:dateTime "2010-01-01T12:00:00+00:00"^^xsd:dateTime Here are some example literals that are not identical: # floats and decimals are drawn from different pools of values "1.000"^^xsd:float "1"^^xsd:integer # according to OWL 2 these are "equal but not identical". "2010-01-01T12:00:00+00:00"^^xsd:dateTime "2010-01-01T11:00:00-01:00"^^xsd:dateTime This latter example is affected by "force_utc". · "literal_to_perl($lit)" Returns a scalar value for the literal, or an appropriate object with overloaded operators (e.g. DateTime, Math::BigInt). Variables $RDF, $RDFS, $OWL and $XSD may also be exported as a convenience. These are RDF::Trine::Namespace objects. Don't modify them. Object-Oriented Interface use RDF::Trine; use RDF::Closure::DatatypeHandling qw[$XSD]; my $lit = RDF::Trine::Node::Literal->new( "2010-01-01T11:00:00-01:00", undef, $XSD->dateTime); my $handler = RDF::Closure::DatatypeHandling->new(force_utc => 1); print $handler->literal_canonical($lit)->as_ntriples;
SEE ALSO RDF::Closure. <http://www.perlrdf.org/>.
AUTHOR Toby Inkster <@cpan.org>.
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 v5.20.2 2012-06-28 RDF::Closure::DatatypeHandling(3pm)