SWI-Prolog -- iri_xml

Availability::- use_module(library(sgml)).(can be autoloaded)

[det]iri_xml_namespace(+IRI, -Namespace, -Localname)

Split an IRI (Unicode URI) into its Namespace (an IRI) and Localname (a Unicode XML name, see xml_name/2). The Localname is defined as the longest last part of the IRI that satisfies the syntax of an XML name. With IRI schemas that are designed to work with XML namespaces, this will typically break the IRI on the last # or /. Note however that this can produce unexpected results. E.g., in the example below, one might expect the namespace to be http://example.com/images\#, but an XML name cannot start with a digit.

?- iri_xml_namespace('http://example.com/images#12345', NS, L).
NS = 'http://example.com/images#12345',
L = ''.

As we see from the example above, the Localname can be the empty atom. Similarly, Namespace can be the empty atom if IRI is an XML name. Applications will often have to check for either or both these conditions. We decided against failing in these conditions because the application typically wants to know which of the two conditions (empty namespace or empty localname) holds. This predicate is often used for generating RDF/XML from an RDF graph.