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Re: Comment on xmlIDsemantics32

From: <noah_mendelsohn@us.ibm.com>
Date: Mon, 16 Jun 2003 11:59:17 -0400
To: Chris Lilley <chris@w3.org>
Cc: "Dare Obasanjo" <dareo@microsoft.com>, "Glenn A. Adams" <glenn@xfsi.com>, www-tag@w3.org
Message-ID: <OFDF4CBE8D.A56AC0AA-ON85256D47.0056CDFA@lotus.com>

>> "Validation and typing are separable but often conflated concepts. 
IDness is a consequence of parsing a DTD, not of validation."

This seems too strong.  Certainly there are situations in which typing (or 
assignment of defaults, etc.) is best thought of as separate from 
validation.  I respect that there are those who believe that the two 
notions are often or always better separated.  I'm not sure it's fair to 
say that there is concensus on that.  Consider, for example, locally 
scoped elements.  Without writing out the whole schema, lets look at an 
example of a simple bibliography reference:

<book>
        <isbn>0553213113</isbn>
        <title>Moby Dick</title>
        <author>
                <title>Mr.</title>
                <firstName>Herman</firstName>
                <lastname>Melville</lastName>
        </author>
</book>

Note the two uses of a <title> element.  In W3C XML schema, we might guess 
that the <title> that's a child of <book> would be <xsd:string>.  The 
<title> that's within the <author> field might better be typed as an 
enumeration of {Mr. Mrs., Ms., Dr., etc.}.  Is it not natural in practice 
to combine the process of validation, which establishes the context to 
determine correctness, with the process of assigning (and if desired 
validating against ) the type? 

I can see that there are two sides of this issue, but I think it's a bit 
too glib just just say that these "ARE separable but often conflated".

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Noah Mendelsohn                              Voice: 1-617-693-4036
IBM Corporation                                Fax: 1-617-693-8676
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Received on Monday, 16 June 2003 12:00:35 UTC

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