NAMESPACES: expressing commonality or distinction

[Ann Navarro]

At 10:12 AM 8/30/99 +0800, James Tauber wrote:

>However, as David Megginson and Tim Bray have argued, capturing the
>commonality between, say, "p" in each DTD is not just valuable, but pretty
>much vital.

I think that the distinctions are just as vital, from the global
perspective, not just from an application developer perspective. 

>It seems to me that this is an argument to expand the role of namespaces (to
>express commonality, not just distinction) on grounds of practicality.
>
>I imagine that most people would agree that:
>
>1. There is a difference between strict:p and transitional:p
>2. The difference is small and most applications will not care about it
>3. Most applications *will* care about the commonality

If the qualifier were "many", rather than "most', I indeed agree (though
that's splitting hairs). 


>Here are a couple of possibilities:
>
>1. PREFIX MATCHING ON NAMESPACE URIs
>
>Use URIs to develop a hierarchy of namespaces and then allow
>underspecification for matching via prefixes.
>
>Use the Namespace URIs:
>
>http://www.w3.org/HTML/Strict/1.0
>http://www.w3.org/HTML/Transitional/1.0
>
>and allow applications to match
>
>http://www.w3.org/HTML


>PRO: uses existing namespace mechanism
>CON: would require modification to XPath, etc.

I like it -- XPath isn't completely done yet (though we are in last call,
so it is a bit late)


>2. A COMMON ATTRIBUTE THAT CAN BE MATCHED
>
>Have all elements in all three DTDs take a FIXED attribute. For example:
>
>    w3c:vocab="HTML" xmlns:w3c="http://www.w3.org/"

>PRO: doesn't require modification of XPath, etc.
>CON: invents new mechanism

I think it's realistic that we may indeed need a new mechanism. 

Either one seems a viable option to me. 

Ann


---

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