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RE: 'is-a' Relationships in XML?

• From: "stephengreenubl@gmail.com" <stephengreenubl@gmail.com>
• To: "Michael Kay" <mike@saxonica.com>
• Date: Mon, 03 May 2010 22:49:25 +0000

-----Original Message----
From: Michael Kay
Sent:  03/05/2010 11:35:35 pm
To: stephengreenubl@gmail.com
Cc: 'xml-dev'
Subject:  RE:  'is-a' Relationships in XML?

> So making an 'employee' element  a child of an 'employer' 
> element clearly implies some semantics that the employer 
> 'has' the employees. 

And if 'employer' is a child of 'employee' then I suppose that the employee
"has" the employer. But I don't think there's any semantics here: you're
just using "has" as a synonym for "is the parent node of". 


-sdg:
Not really. I think I'd be understanding that the markup was using the parent/child to represent the reality of the 'has' relationship. I accept that it's implicit to some extent but even the names of the elememts could be said to imply something about the reality being represented. Just as words represent reality, to some extent implicitly.



If XML is well designed, then you can make guesses about the meaning of the
data from the choice of element names and their hierarchic relationships.
But XML is often badly designed, and your guesses in such cases will be
wrong.

Regards,

Michael Kay
http://www.saxonica.com/
http://twitter.com/michaelhkay