Re: wildcard

Rahul Srivastava wrote:

> Thank you very much Eric. That was an excellent explaination.


Although not an answer to your question ;=) ... sorry!


> 
> But, the second part is yet not very clear. 3.10.6 of the specification defines 
> schema component constraint viz. wildcard subset, attribute wildcard union and 
> attribute wildcard intersection.
> 
> Can you tell, when do you need to check for such constraints.


This needs to be read after the explanation, in 3.10.2 of how the XML 
representation of the wildcard is transformed into "namespace constraint":

<quote>
{namespace constraint}Dependent on the ·actual value· of the namespace 
[attribute]: if absent, then any, otherwise as follows:

##any:
  any
##other:
  a pair of not and the ·actual value· of the targetNamespace [attribute]
  of the <schema> ancestor element information item if present, otherwise
  ·absent·.
otherwise:
     a set whose members are namespace names corresponding to
     the space-delimited substrings of the string, except
     1 if one such substring is ##targetNamespace, the corresponding
       member is the ·actual value· of the targetNamespace [attribute] of
       the <schema> ancestor element information item if present,
       otherwise ·absent·.
     2 if one such substring is ##local, the corresponding member is
       ·absent·.
</quote>

My understanding is that even though 3.10.6 is describing a fairly 
general mechanism with intersections, unions and exclusions, the XML 
representation doesn't allow all the combinations to be described (for 
instance, you cannot represent the expression "any namespace that isn't 
defined" nor even "any namespaces except a and b".

Eric


> 
> Cheers,
> Rahul.
> 
> 
> 



-- 
See you in Scottsdale, Arizona.
      http://xmlconnections.com/xml/xmlfall2001/speakers.asp#evandervlist
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Eric van der Vlist       http://xmlfr.org            http://dyomedea.com
http://xsltunit.org      http://4xt.org           http://examplotron.org
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Received on Thursday, 20 September 2001 10:00:37 UTC