W3C home > Mailing lists > Public > xml-names-issues@w3.org > July to September 1998

Re: PI target names unscoped -- why?

From: David Brownell <db@Eng.Sun.COM>
Date: Sun, 16 Aug 1998 09:59:15 -0700
Message-ID: <35D70FE3.ABC7610@eng.sun.com>
To: James Clark <jjc@jclark.com>
CC: xml-names-issues@w3.org
James Clark wrote:
> 
> David Brownell wrote:
> >
> > The "motivation" (why not clearly defined "goals"?) in the XML
> > namespace draft defines combining "markup from multiple independent
> > sources" as needing namespace collision avoidance mechanisms.  ...
> 
> I think the use of the word "markup" in section 1 is deeply confusing.
> Markup is a syntactic notion, and we are not trying to solve the problem
> of syntactically combining independently written XML instances or XML
> DTDs ...

But that's exactly how I, and other folk, read those words.  The
nub of the misunderstanding seems to be that there's no statement
about what's really intended for re-use.  It's only some syntax
and vocabularies; not actual markup or declarations, code generating
such markup, or code that now recognizes/processes such markup.

Leading to a repeat of the plea to have the actual goals be very
clearly identified!!  Ditto non-goals.


>	 The problem we're
> solving is that of semantic combination, how to create a document that
> uses element types and attributes whose semantics are defined by
> multiple independent sources and how to have those semantics be
> recognizable by the appropriate software package.

That goal isn't something I could deduce from the namespace draft
at all!  It does jive with a document I found recently, though:

    http://www.w3.org/TR/NOTE-webarch-extlang

Perhaps that document should get a reference, since it seems to be
describing the current goal set better than this namespace draft.


>	 I would suggest
> something like:
> 
> "We envisage the use of XML documents that draw their element types and
> attributes from multiple vocabularies (collections of element types and
> attributes with defined semantics). One motivation for this is
> modularity; if there is a vocabulary available which is well-understood
> and for which there is useful software available, it is better to re-use
> this vocabulary rather than re-invent it.
> 
> Such documents, containing elements and attributes from multiple
> vocabularies, pose problems of recognition and collision. Software
> modules need to be able to recognize the element types and attributes
> rrom the vocabulary that they are designed to process, even in the face
> of "collisions" occurring when element types and attributes from another
> vocabulary uses the same element type or attribute name."

MUCH better!!

I'd still prefer to see at least a recognition of the problem that
the draft's approach only aims for the "trivial subset" of XML (sans
validation of DTD based declarations).  Similarly, to see a statement
about replacing the existing declaration mechanism with TBD schema
mechanisms to regain the DTD based error checking that appears to be
getting discarded.

- Dave



> > However, even such an unstated "anti-DTD" goal does not motivate
> > the current conformance requirment precluding PI targets from being
> > scoped, since they are not tied to DTDs.
>
>	...
> 
> I would like to see a future version of the spec solve this problem, but
> I think leaving it for later is reasonable.
> 
> James
Received on Sunday, 16 August 1998 13:02:01 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 19:43:30 UTC