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RE: [DM] 7.7.3 Construction (of text nodes) from an Infoset

From: Michael Rys <mrys@microsoft.com>
Date: Thu, 29 Jul 2004 12:44:48 -0700
Message-ID: <EB0A327048144442AFB15FCE18DC96C70388A153@RED-MSG-31.redmond.corp.microsoft.com>
To: "David Carlisle" <davidc@nag.co.uk>, <public-qt-comments@w3.org>

During processing last-call comments, we made the following change:

An XQuery text node constructor text{} can construct text nodes with no
content. However adding such a text node to the content of an element
will make it disappear.

It may be that this change was reflected incompletely in the data model
spec.

Best regards
Michael

> -----Original Message-----
> From: public-qt-comments-request@w3.org [mailto:public-qt-comments-
> request@w3.org] On Behalf Of David Carlisle
> Sent: Thursday, July 29, 2004 8:12 AM
> To: public-qt-comments@w3.org
> Subject: [DM] 7.7.3 Construction (of text nodes) from an Infoset
> 
> 
> 
> I commented here:
> 
>
http://lists.w3.org/Archives/Public/public-qt-comments/2003Dec/0085.html
> 
> On an earlier draft of DM that the handling of white space was
> dangerously (explicitly) undefined.
> 
> That part of the document has changed out of all recognition
> but the relevant details appear now to be in section
> 7.7.3 on constructing a text node from an infoset.
> 
> Section 7.7 leaves me very confused.
> 
> It starts by saying:
> 
>     Text Nodes must satisfy the following constraint:
> 
>     If the parent of a text node is not empty, the Text Node must not
>     contain the empty string as its content.
> 
> which is fine
> 
> but
> 
> 7.7.3 Construction from an Infoset
> 
> says
> 
>    If the resulting Text Node consists entirely of white space and the
>    Text Node occurs in Element contentXML, the content of the Text
Node
>    is the empty string.
> 
> If the element is in Element content then it (presumably) has some
> element as its parent, so being the empty string would invalidate the
> quoted constraint.
> 
> Perhaps what was meant was that
> 
>    If the resulting Text Node would consist entirely of white space
and
>                               ^^^^^
>    occurs in Element contentXML, then no node is constructed.
> 
> 
> However this would still be confusing.
> 
> It says "The Text Node occurs in Element contentXML" but the Text node
> is the thing that's being constructed in the instance of this data
> model. the XML spec says nothing about that. What is presumably meant
is
> that the element in the original XML document on which the infoset is
> based has element content, but that can't be the case unless it was
> parsed with a DTD validating parser.
> 
> If that is what is intended, that DTD-valid documents have white space
> in declared element content removed, that is (I suppose) better than
the
> previous draft as it is at least definite, not left up to the
> implementation, but it still introduces large differences in behaviour
> between XPath 1 and Xpath 2 where by default this white space is
always
> seen.
> 
> It would be preferable for the DM never to remove such white space (by
> default) and leave it to higher level switches such as
<xsl:strip-space
> to remove the nodes (whether or not they are in declared element
content)
> 
> David (even more confused than usual:-)
> 
> 
> 
>
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Received on Thursday, 29 July 2004 15:45:03 GMT

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