- From: Jonathan Borden <jborden@mediaone.net>
- Date: Sun, 4 Feb 2001 10:12:32 -0500
- To: "McBride, Brian" <bwm@hplb.hpl.hp.com>
- Cc: "RDF interest group" <www-rdf-interest@w3.org>
Brian,
> >
> > <rdf:Seq rdf:ID="foo">
> > <rdfx:member>bar</rdfx:member>
> > <rdfx:member>baz</rdfx:member>
> > </rdf:Seq>
> >
> > can be addressed as:
> >
> > #foo/1
> > #foo/2
>
> If there was an RDF graph representation of the above,
> e.g. in statement form:
>
> { (foo, rdf:type, rdf:Seq),
> (foo, rdfx:member, "bar"),
> (foo, rdfx:member, "baz")
> }
>
> an application which wanted to convert this to RDF XML
> wouldn't know in which order to write the
> members. Something more is needed to capture the
> ordering in the graph.
>
Right. First assume that rdfx:member is a synonym for rdf:li, then the
statements produced are:
[foo rdf:type rdf:Seq]
[foo rdf:_1 "bar"]
[foo rdf:_2 "baz"]
or as a child sequence:
[foo /1 "bar"]
[foo /2 "baz"]
there are other possibilities to generate XPaths (where full XPointer is a
superset of XPath) e.g.
[foo rdfx:member[1] "bar"]
[foo rdfx:member[2] "baz"]
one might then encode the fact that XXX xpointer isa rdf:member by
statements such as
[foo/1 rdf:type rdfx:member]
[foo/2 rdf:type rdfx:member]
or even
[foo/rdfx:member[1] rdf:type rdfx:member]
[foo/rdfx:member[2] rdf:type rdfx:member]
the point being that through use of an XPointer as the fragment id part of a
URI, collections can be implemented. Another reason to introduce XPointer
into RDF is that any so-called anonymous node can be named as a child
sequence or full xpointer.
Furthmore the concept of a range allows an entire sequence to be expressed
as
foo/0 ... foo/A
Jonathan Borden
The Open Healthcare Group
http://www.openhealth.org
Received on Sunday, 4 February 2001 10:09:56 UTC