X-Schema syntax

[Andy Dent]

At 15:11 -0400 28/6/99, Paul Prescod wrote:
>There are not many elements that appear in one and only one context.
>Therefore it is necessarily the case that readers must put definitions in
>context "in their heads." When you see the definition for LI in HTML OL,
>you need to keep in your head the fact that that same element type can
>occur in HTML UL.

This is in a document domain. XML has a wider application. I have 
absolutely no argument with separate element definitions being 
available, just believing that there is a significant scope of 
applying XML where contextual definitions will be useful and quite 
possibly more usable.

I think we need to be very careful about distinguishing HTML or 
similar documents from mapping database tables and other tabular 
information (eg: spreadsheets) where users typically have unprefixed 
local elements with meaning determined by context.

Your example of LI appearing in OL and UL is interesting because it 
opens up a wider typing issue. LI can't appear in a P element and it 
doesn't make sense to a user for it to appear there. If OL and UL are 
regarded as flavours of "List" then LI appearing in both is valid.

The semantic model of a list, which may be ordered or unordered, maps 
onto the syntactic model of the OL or UL container.

My perspective is different from many (most?) people on this list. I 
have no SGML background or other document orientation. I combine 
database API thinking with a lot of work on UI design, particularly 
for naive users. I've been working on user interfaces for databases 
for years, mainly on the Mac, and so a lot of my thinking is coloured 
by the models I've seen people apply. I've also spent a lot of time 
mentoring junior programmers and designing our tool API's for that 
audience.

Andy Dent BSc MACS AACM, Software Designer, A.D. Software, Western Australia
OOFILE - Database, Reports, Graphs, GUI for c++ on Mac, Unix & Windows
PP2MFC - PowerPlant->MFC portability
http://www.oofile.com.au/

xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at ic.ac.uk
Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1
To (un)subscribe, mailto:majordomo at ic.ac.uk the following message;
(un)subscribe xml-dev
To subscribe to the digests, mailto:majordomo at ic.ac.uk the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa at ic.ac.uk)