xml-dev - Re: Schema concepts

[Stefan Haustein <haustein@kimo.cs.uni-dortmund.de>]

Hello!

I was asked to give an example why I consider
the current XML schema syntax too complicated.

So, suppose I want to describe pictures built of 
circles, lines and rectangles.

The first example is how I would expect 
schema coding if I am used to OOP:
 
  <element name="pictureElement" abstract="true">...</element>

  <element name="picture">
    <element minOccurs="0" maxOccurs="*" ref="pictureElement"/>
  </element>

  <element name="circle" source="pictureElement"/>...</element>

  <element name="line" source="pictureElement"/>...</element>

The second example is what I really 
need to do using the current XML Schema draft:

  <type name="pictureElement">...</type>

  <element name="pictureElement" type="pictureElement"/>

  <element name="picture">
    <type>
      <element minOccurs="0" maxOccurs="*" ref="pictureElement"/>
    </type>
  </element>


  <type name="circle" source="pictureElement">...</type>

  <element name="circle" type="circle" equivClass="pictureElement"/>
 
  <type name="line" source="pictureElement">...</type>

  <element name="line" type="line" equivClass="pictureElement"/>
     

The circle and line elements cannot just have 
annonymous types since I may want to reuse 
their structure. 

Now, my question is: Is anyone able to generate
a counter-example that justifies the
current schema overhead?  

Best regards

Stefan 

-- 
Stefan Haustein
University of Dortmund
Computer Science VIII
www-ai.cs.uni-dortmund.de

-- 
Stefan Haustein
University of Dortmund
Computer Science VIII
www-ai.cs.uni-dortmund.de