Users Guide¶

Terms and Definitions¶

We use the official definitions of https://www.w3.org/TR/rdf11-concepts/.

Framework Basics¶

The main types of rdf4cpp:

rdf4cpp::Node: Base class of Literal, IRI and BlankNode

rdf4cpp::IRI: An IRI.

rdf4cpp::Literal: A Literal containing some data.

rdf4cpp::BlankNode: A Blank Node used to connect other Nodes.

rdf4cpp::Statement: A basic rdf statement consisting of Subject, Predicate and Object.

rdf4cpp::Quad: A Statement with added Graph.

rdf4cpp::Graph: A Collection of Statements, with the ability to execute simple Queries.

rdf4cpp::Dataset: A Collection of Quads, with the ability to execute simple Queries.

rdf4cpp::Namespace: A namespace that makes constructing IRIs with common prefix easier.

rdf4cpp::query::Variable: A Variable used in Queries.

rdf4cpp::query::TriplePattern: A Query patterns of Subject, Predicate and Object.

rdf4cpp::query::QuadPattern: A Query of Graph, Subject, Predicate and Object.

rdf4cpp::query::Solution: A single matched Solution, with all Variables bound.

Datatypes¶

Literal supports common rdf Datatypes and operations on them (as defined in https://www.w3.org/TR/sparql12-query/#SparqlOps), as well as conversions between Literal Datatypes.

You can find all supported Datatypes here:

Namespace rdf4cpp::datatypes::xsd: XSD datatypes.

Namespace rdf4cpp::datatypes::rdf: RDF datatypes (LangString).

Namespace rdf4cpp::datatypes::owl: OWL datatypes.

Parsing Files¶

The class rdf4cpp::parser::RDFFileParser allows reading files containing rdf Statements and iterate over them. Supported Formats: Turtle, TriG, N-Triples N-Quads and RDF/XML. rdf4cpp::parser::IStreamQuadIterator allows doing the same over arbitrary data streams.

Relaxed Parsing Mode¶

The setting rdf4cpp::datatypes::registry::relaxed_parsing_mode disables IRI validity checks and allows rdf4cpp to automatically try to correct some faulty Literals. See the linked relaxed_parsing_mode for a full list of changes. Currently aimed at reducing loading errors with DBPedia, more might be added in future versions.

(since rdf4cpp v0.0.24)