Musing over Namespaces

Wed Dec 15 03:48:45 GMT 1999

<boblq>
 <quote>
   <author>
     <lastname>Park</lastname>
     <firstname>Don</firstname>
   </author>
   Is it really a 'good thing' to have namespaces in XML?  
 </quote>

Probably not as defined by W3 in the current rec, but ...

 <quote>
   <author>
     <lastname>Reynolds</lastname>
     <firstname>Gregg</firstname>
   </author>
   Do you mean "a means of scoping names, so that a local, apparently atomic
   name can be mapped to a universal name"?  Yes.  
 </quote>

 <quote>
   <author>
     <lastname>Park</lastname>
     <firstname>Don</firstname>
   </author>
   What ill effect will it have on XML's future?  
 <quote>

Like all unnecessary complexity it gets in the way of thinking 
clearly about the problem one is trying to solve. 

 <quote>
   <author>
     <lastname>Park</lastname>
     <firstname>Don</firstname>
   </author>
   Why can't the semantic of '<name>' be determined purely by context?  
  </quote>

It can. An "elements only" argument was given earlier.

 <quote>
   <author>
     <lastname>Seivers</lastname>
     <firstname>Kent</firstname>
   </author>

	As evidence of this I give 

	1) almost every other object oriented language in existence.  
	   author.name.firstname = 'joe' is easy to understand, and, 
	   behind the scenes, since even even an INT is an object 
	   and even an "=" is a function, is entirely done in the 
	   spirit of "elements only" and 

	2) the obvious nature of everyones first XML tutorial in which 
	   they are typically shown something like 
	   <author><firstname>joe<firstname/><author/> and 
	   understand it completely.
 </quote>

 <quote>
   <author>
     <lastname>Park</lastname>
     <firstname>Don</firstname>
   </author>
   What is wrong with using just <html> to distinguish 
   HTML's use of 'a' tag?  
 </quote>

Nothing in a fully qualified (hierarchical, See Clark Evan's remarks and 
example above) context. The <boblq> tag would disambiguate the <html>.

>Is the ability to inject attributes from other namespaces really useful?  

No. 

<sigh>
Yes ... but for legacy reasons 
</sigh> 

 <quote>
   <author>
     <lastname>Park</lastname>
     <firstname>Don</firstname>
   </author>
   What is the positive effect of having just one namespace?  
 </quote>

The systematic development of a taxonomic hierarchy closely related
to semantics would follow from having a consistant syntax. As it is,
folks are hiding like ostrichs from this problem which syntax will
never solve. 

 <quote>
   <author>
     <lastname>Park</lastname>
     <firstname>Don</firstname>
   </author>
   Why can't we have central registry of XML names?
 </quote>

Good question. Better question, Why can't we have a distributed
registry? Actually I think, in some sense, as David Meggison has pointed
out such a registration mechanism is the essense of the W3 name identification 
mechanism which is one part of the rec that I do like. 

So I suggest following Don's suggestion:

purchase {http://www.w3.org/ns/} default definition 
         {http://www.sun.com/ns/} variant
         {http://www.ibm.com/ns/} variant
         {http://www.amazon.com/ns/} variant 

where the variants are diffs from the default. I would hope the W3 is
a decent place to get the "default definition" adjudicated. Certainly 
W3 is not Network Solutions ;( but than it is not the IETF either. 

I believe the Jabber guys are working a distributed namespace management 
system for their own purposes but I have not reviewed it. A Jabberite 
might care to comment.

</boblq>

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