Re: RDF/XML/Internet Collisons, Process (was Moving on)

At 08:23 PM 5/31/00 +0100, Graham Klyne wrote:
>At 04:04 PM 5/31/00 -0400, Simon St.Laurent wrote:
>>I don't think it's yet been made clear that XML (apart from RDF) gains
>>anything but additional complexity from making Namespaces into 'first class
>>objects'.  The only gains appear to be on the RDF side.
>>
>>I've suggested repeatedly that RDF would do better to 'bless' namespaces as
>>URIs (and first class objects if you like) within RDF, rather than imposing
>>such an obligation on XML processors.
>
>Now here I feel I must disagree -- RDF, taken in isolation from XML, does 
>not _need_ namespaces in any way that I can see.  URIs are sufficient.  It 
>is the desire to use XML to _represent_ RDF that seems to create this 
>requirement.

Using XML to represent RDF seems to create a large number of complexities
for both parties.

>OTOH, I am currently involved in reviewing a protocol design that uses XML, 
>and find that I am advocating use of namespaces to provide a level of 
>flexibility (evolvability) that is not provided by raw XML.  The key 
>benefit of namespaces seems to be the capacity for "language mixing".

Does that require namespaces to be treated as 'first class objects' or
always handled as URIs in all their glory, complete with relative URIs?

I'm hardly claiming that namespaces are useless - they are in fact great
for 'language mixing' in a lot of different contexts.  That's a property of
naming things, however, not a property of making things 'first class objects'.

>Maybe we're touching different parts of the elephant.  Coming at XML from 
>its historical background of applying markup to textual documents, where 
>the real information is in the text, then maybe namespaces don't offer so 
>much.  But viewing XML as a primary mechanism to construct representations 
>of information (including, but not limited to, RDF) then the namespace idea 
>seems extremely powerful.

Again, my critique is not that namespaces aren't useful, but that the
baggage being imposed on XML's usage of namespaces by particular claims
about the nature of URIs is excessively heavy.

Even in textual documents, namespaces can be very useful.


Simon St.Laurent
XML Elements of Style / XML: A Primer, 2nd Ed.
Building XML Applications
Inside XML DTDs: Scientific and Technical
Cookies / Sharing Bandwidth
http://www.simonstl.com

Received on Wednesday, 31 May 2000 16:56:27 UTC