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Re: 25 Feb Structures Questions

From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
Date: 03 Mar 2000 16:32:37 +0000
To: Michael Anderson <michael@research.canon.com.au>
Cc: xml <xml-dev@xml.org>, www-xml-schema-comments@w3.org
Message-ID: <f5bsny8j9p6.fsf@cogsci.ed.ac.uk>
Michael Anderson <michael@research.canon.com.au> writes:

> I've just done a first pass of the new working draft of XML Schema.  It
> certainly is heavy reading, so I hope I haven't missed the answers to my
> questions below.
> 1. When restricting a complex type, it seems (section 4.4.3 Part 1 &
> section 3.4 Part 0)  one needs to repeat each particle that is present
> in the base type.  I believe this could get messy when there are large
> content models.

Sorry this isn't clear in the draft, but this section (4.4.3) is not
complete, and needs a lot of work to explain the change since the
previous design.

  Especially so as particles listed with different names
> to their respective base particle are simply renamed as opposed to in
> error.

No support for renaming, sorry, which bit of prose suggested there

> So if I miss particle 10 in a list of 20 then the last 10
> particles will use a base particle that is incorrect and also rename
> it.  (Okay, so the total number will raise an error but I'll continue
> anyway).  This may not be such a problem if we don't have 20 particles,
> which raises my question of how to deal with named Content Model
> Groups?  It seems that these need to be expanded in the restricted list,
> leading to the large number of particles.  If this is not the case, then
> how can one restrict particles hidden within these named groups?

In brief, you are restricting the complete content model of the base
type, not the XML representation of it, so you _can_ get at particles
in referenced groups if you wish.  But you don't have to.

> 2. Also with restrictions, if attributes of elements are omitted do they
> default to the standard default or the values defined in the base type
> definition?  Or is it an error to omit attributes previously defined in
> the base?

Do you mean if they are omitted in instances?  If the derived type
definition has defaults, they will get used.

> 3. In Schema Part 0, Appendix E. Document History, there was mention
> that the 16th of Feb draft published had adopted TypeName and
> elementName naming convention.  Was this later dropped?

I don't rmeember the WG adopting this or any other any naming
convention across the board.

  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2001, part-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
		     URL: http://www.ltg.ed.ac.uk/~ht/
Received on Friday, 3 March 2000 11:32:46 UTC

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