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Re:



At 02:59 2000 09 30 +0200, Chris Lilley wrote:
>"Simon St.Laurent" wrote:
>> At 01:33 AM 9/30/00 +0200, Chris Lilley wrote:
>> >> Used in a query string, XPointers could be processed by the server,
>> >
>> >they could be, but then they wouldn't be fragment identifiers. besides,
>> >thats what the XML Query WG is cooking up, right?
>> 
>> I'm not sure why you feel they wouldn't be fragment identifiers.
>
>I am using the term fragment identifiers in the sense it is used in the
>UROI specifications. 

I found a mention of fragment identifier and the # separator in
RFC 2396 [1], but I'm still looking for the discussion of the ?
and | separator (especially, whether they require/allow the entire
resource to be downloaded first or not and exactly where/by whom 
the bit after the | or ? should get processed).  Can someone give
pointers to the specs that answer these questions?  (I've already
looked at RFC 1738, 1808, and 2396.)  Thanks.

[1] ftp://ftp.ietf.org/rfc/rfc2396.txt

>> I strongly hope that the XML Query WG doesn't feel compelled to reinvent
>> this particular wheel or worse, create a syntax that bars the reuse of
>> XPointers for this work. 
>
>My understanding is that their work builds on XPointer.

You should read the following public documents if you want to know more:

XML Query Requirements -- W3C Working Draft 15 August 2000
http://www.w3.org/TR/xmlquery-req

XML Query Data Model -- W3C Working Draft 11 May 2000
http://www.w3.org/TR/query-datamodel/

Quoting from the Intro of the latter document:

 Several XML data models have been developed in the W3C
 Activities. The XML Information Set
 (http://www.w3.org/TR/xml-infoset) provides a description
 of the information available in a well-formed XML document.
 The XPath Recommendation ( http://www.w3.org/TR/xpath), which is
 used by both XSLT ( http://www.w3.org/TR/xslt) and XPointer 
 ( http://www.w3.org/TR/xptr), contains a data model and a
 mapping that relates the XPath data model to the XML Information
 Set (hence ``Infoset''). The Document Object Model
 ( http://www.w3.org/TR/DOM-Level-2/) is an API for HTML
 and XML documents, but it does imply an underlying abstract
 data model. The XML Schema Working Group is defining features,
 such as structures (http://www.w3.org/TR/xmlschema-1) and
 datatypes (http://www.w3.org/TR/xmlschema-2), that extend
 an instance of the XML Information Set
 with more precise type information. 

 The XML Query Data Model defines formally the information
 contained in the input to an XML Query processor; in other
 words, an XML Query processor evaluates a query on an instance of the
 XML Query Data Model. Our model is based on the XML Information
 Set, but it requires the following new features to meet the
 XML Query Working Group's requirements: . . .

You should draw your own conclusions about the relationship
between XPointer and XML Query, but it is not obvious that
XML Query will end up with either a model or a syntax that
is a subset of XPointer.  (And I'm not saying that they should
or shouldn't, but it sounded a bit like Simon might have an
opinion on that question.)

paul