Re: [xml-dev] Victory has been declared in the schema wars ...

[peter murray-rust <pm286@cam.ac.uk>]

At 04:31 01/12/2006, Rick Jelliffe wrote:
>Costello, Roger L. wrote:
>>Hey Rick,
>>
>IMHO, ultimately grammars will be a niche technology: an 
>implementation technology or
>optimization under the hood, a niche schema language when you have 
>repeating structures that are
>not tagged explicitly...perhaps even the internal format for an XML 
>IDE.  I seem to be the only
>person in the world who believes this, which must be embarrassing 
>for everyone else. :-)
Well you have at least one friend - me - who (I think) subscribes to 
your view. In developing CML I commit to the concept of XML elements, 
attributes, namespaces and textual content. I do not find content 
models useful and plan to scrap them. It would be very nice to have 
other friends in this area who are thinking this way.

I use and like Schematron and it is partially sufficient for my 
needs. The major problems are that I need access to additional 
library functionality (e.g. I wish to calculate sines and 
determinants), I need storage (the logic of chemistry is too complex 
to hold in XSLT1.0), and the slightly trivial point that XSLT1.0 is 
poor for whitespaced attribute lists. Other than that I want 
constraints that are easily expressed in Schematron and include 
things like parents and grandchildren.

A major use of the schema is to autogenerate code and so I would like 
functionality like "this element may | must | must_not contain these 
children" and similarly for parents. This allows my to generate code 
that may be  valuable to the developers.

We are also increasingly moving to a time where we have a fluid 
community that is developing its own microformats in CML. These will 
be specified by conventions rather than formal grammars. Many of 
those conventions will be expressible at least in part by Schematron 
- i.e. a Schematron for each convention.

I'd be particularly interested in anyone working in a similar type of 
fluid environment.

P.



Peter Murray-Rust
Unilever Centre for Molecular Sciences Informatics
University of Cambridge,
Lensfield Road,  Cambridge CB2 1EW, UK
+44-1223-763069