Re: [xml-dev] Does the XML syntax have an underlying data model?

[Michael Kay <mike@saxonica.com>]

> On 16 Apr 2016, at 17:11, Costello, Roger L. <costello@mitre.org> wrote:
> 
> Michael Kay wrote:
> 
>> The Namespaces in XML spec came from the XML Core working group. 
>> As with the XML spec itself, the group chose (in my view unwisely) to
>> define a syntax with no underlying data model. 
> 
> I read Michael's words to say:
> 
> 	XML has no underlying data model.
> 
> Isn't the XML Infoset considered to be XML's underlying data model?
> 

The Infoset spec refers to the XML spec, but not the other way around. In terms of layering, the Infoset is an overlay on top of XML, not an underpinning. So it's not an "underlying" data model, rather an "overlying" one.

Yes, the Infoset can be taken as the data model for XML. But it is an after-the-event rationalisation; it did not influence the design of XML. It also came too late to influence other specifications; for example in the XPath data model, namespace nodes have parents, whereas in the Infoset, namespace information items do not. 

Michael Kay
Saxonica