rdf_ntriples.pl -- Process files in the RDF N-Triples format

The library(semweb/rdf_ntriples) provides a fast reader for the RDF N-Triples and N-Quads format. N-Triples is a simple format, originally used to support the W3C RDF test suites. The current format has been extended and is a subset of the Turtle format (see library(semweb/turtle)).

The API of this library is almost identical to library(semweb/turtle). This module provides a plugin into rdf_load/2, making this predicate support the format ntriples and nquads.

See also

- http://www.w3.org/TR/n-triples/

To be done

- Sync with RDF 1.1. specification.

 read_ntriple(+Stream, -Triple) is det

Read the next triple from Stream as Triple. Stream must have UTF-8 encoding.

Arguments:

Triple

- is a term triple(Subject,Predicate,Object). Arguments follow the normal conventions of the RDF libraries. NodeID elements are mapped to node(Id). If end-of-file is reached, Triple is unified with end_of_file.

Errors

- syntax_error(Message) on syntax errors

 read_nquad(+Stream, -Quad) is det

Read the next quad from Stream as Quad. Stream must have UTF-8 encoding.

Arguments:

Quad	- is a term quad(Subject,Predicate,Object,Graph). Arguments follow the normal conventions of the RDF libraries. NodeID elements are mapped to node(Id). If end-of-file is reached, Quad is unified with end_of_file.

Errors

- syntax_error(Message) on syntax errors

 read_ntuple(+Stream, -Tuple) is det

Read the next triple or quad from Stream as Tuple. Tuple is one of the terms below. See read_ntriple/2 and read_nquad/2 for details.

• triple(Subject,Predicate,Object)
• quad(Subject,Predicate,Object,Graph).

 rdf_read_ntriples(+Input, -Triples, +Options) is det

 rdf_read_nquads(+Input, -Quads, +Options) is det

True when Triples/Quads is a list of triples/quads from Input. Options:

anon_prefix(+AtomOrNode)

Prefix nodeIDs with this atom. If AtomOrNode is the term node(_), bnodes are returned as node(Id).

base_uri(+Atom)

Defines the default anon_prefix as _:<baseuri>_

on_error(Action)

One of warning (default) or error

error_count(-Count)

If on_error is warning, unify Count with th number of errors.

graph(+Graph)

For rdf_read_nquads/3, this defines the graph associated to triples loaded from the input. For rdf_read_ntriples/3 this opion is ignored.

Arguments:

Triples	- is a list of rdf(Subject, Predicate, Object)
Quads	- is a list of rdf(Subject, Predicate, Object, Graph)

 rdf_process_ntriples(+Input, :CallBack, +Options)

Call-back interface, compatible with the other triple readers. In addition to the options from rdf_read_ntriples/3, this processes the option graph(Graph).

Arguments:

CallBack

- is called as call(CallBack, Triples, Graph), where Triples is a list holding a single rdf(S,P,O) triple. Graph is passed from the graph option and unbound if this option is omitted.

 rdf_db:rdf_load_stream(+Format, +Stream, :Options) is semidet[multifile]

Plugin rule that supports loading the ntriples and nquads formats.

 rdf_db:rdf_file_type(+Extension, -Format)[multifile]

Bind the ntriples reader to files with the extensions nt, ntriples and nquads.

Re-exported predicates

The following predicates are exported from this file while their implementation is defined in imported modules or non-module files loaded by this module.

 rdf_read_ntriples(+Input, -Triples, +Options) is det

 rdf_read_nquads(+Input, -Quads, +Options) is det

True when Triples/Quads is a list of triples/quads from Input. Options:

anon_prefix(+AtomOrNode)

Prefix nodeIDs with this atom. If AtomOrNode is the term node(_), bnodes are returned as node(Id).

base_uri(+Atom)

Defines the default anon_prefix as _:<baseuri>_

on_error(Action)

One of warning (default) or error

error_count(-Count)

If on_error is warning, unify Count with th number of errors.

graph(+Graph)

For rdf_read_nquads/3, this defines the graph associated to triples loaded from the input. For rdf_read_ntriples/3 this opion is ignored.

Arguments:

Triples	- is a list of rdf(Subject, Predicate, Object)
Quads	- is a list of rdf(Subject, Predicate, Object, Graph)