[relax-ng] Re: DOM Abstract Schemas revisited

[Kohsuke KAWAGUCHI <kohsuke.kawaguchi@sun.com>]

> I believe that it is in fact possible to map RELAX NG schemas to
> the DOM Abstract Schema (AS) model, with a *very* small number of
> extensions, perhaps only one. I have written an RNX schema for a
> serialization of the AS model as of 2002-01-14: see below.

I still don't think it's possible --- at least without a significant
mangling of the semantics.

For example,

-  ASModel has a map from name(string) to ASElementDecl. This doesn't
   match RELAX NG's semantics where we don't have globally identifiable
   name for element declarations.

   ASModel doesn't allow the schema to express the constraint about the
   top level. So the only way for applications to get a reference to
   ASElementDecl is through ASModel.elementDecls. If you set them all to
   empty, how can the application access schema information?
   

-  RELAX NG has a pattern, which is globally identifiable. How can we
   represent this concept in ASModel?


-  How do we represent attribute&element mixed content model in AS? For
   example, how do you represent
   
   <element name="foo">
     <choice>
       <attribute name="address" />
       <element name="address"><text/></element>
     </choice>

   ?


- The ASElementDecl.contentType property doesn't make sense at all for
  RELAX NG. If an element is declared as:
  
  <element name="foo">
    <choice>
      <data type="integer"/>
      <element name="child"><empty/></element>
    </choice>
  </element>
  
  Then what value should the contentType property should have?



There are just top four items from my endless list of incompatibility...

regards,
--
Kohsuke KAWAGUCHI                          +1 607 257 0037
Sun Microsystems                   kohsuke.kawaguchi@sun.com