RE: Alternatives to XML for RDF?

> -----Original Message-----
> From: ext Charles McCathieNevile [mailto:charles@w3.org]
> Sent: 12 August, 2003 03:58
> To: Ashley Yakeley
> Cc: www-rdf-interest@w3.org
> Subject: Re: Alternatives to XML for RDF?
> 
> XML is nice because it can be used with XML tools - XQuery, 
> Xforms, XSLT,

For RDF, the use of XML does not actually invite the use
of XML tools such as above, as they cannot be used 
effectively for arbitrary RDF/XML schemas.

This is because there is an N:1 relation between RDF/XML
instances and graphs. While one may work to normalize
the RDF/XML in various ways, the effort to do so safely
(per the RDF MT) is usally equal to or greater than
parsing the RDF/XML into a graph, so why bother.

Operating directly on RDF/XML is a bad idea. One should
always deal with an RDF graph -- and once you've gotten
to the graph, the XML is gone, and is no longer an issue.

The one tool that might be used effectively with RDF/XML is
an XML editor that simply does well-formedness checking. You
can't do actual XML validation, because you can't write a
DTD or XML Schema for RDF (it's element and attribute
name sets are infinite).

RDF/XML is actually more like a set of architectural
forms than an XML content model.

The W3C would do well to consider adoption of either a
subset of N3, limited to the expressiveness of RDF/XML,
or a completely revamped, and XML Schema defined XML 
serialization.

I don't think there are many, if any, fans of RDF/XML.
It is a means to an end (the graph) and a pretty ugly
and problemmatic means at that.

That's a pity, because alot of folks get turned off by
the XML serialization and miss the real beauty and
power of RDF (there's probably a classic fairy tale
in there somewhere ;-)

Patrick

--
Patrick Stickler
Nokia, Finland
patrick.stickler@nokia.com

Received on Tuesday, 12 August 2003 06:28:42 UTC