OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.


Help: OASIS Mailing Lists Help | MarkMail Help



   XQL and XPointer

[ Lists Home | Date Index | Thread Index ]
  • From: Paul Prescod <paul@prescod.net>
  • To: xml-dev <xml-dev@ic.ac.uk>
  • Date: Wed, 31 Mar 1999 11:54:46 -0600

Oren Ben-Kiki asks:
> Actually, what is the difference between XPointer syntax and XQL (as defined
> above)? Both allow matching elements according to the structure of the XML
> tree and/or the value of attributes. The syntax is different and the set of
> capabilities doesn't exactly match. Is it just due to historical reasons
> that XSL isn't using (possibly enhanced) XPointers in its match patterns?

Yes the reasons are mostly historical but there are technical issues. The
XPointer "model" is to select a contiguous, perhaps non-well formed range
of data. The XSL model is to select a list of well-formed, perhaps
non-contiguous nodes.

I don't think that there is anything wrong from a hypertext-theoretic
point of view with having pointers return non-contiguous nodes. And you
can simulate non-well-formedness:

This is text <EMPH>and this is some</EMPH> more text.
     ^                      ^

In this case we could simulate a link from the first occurence of "is" to
the second by selecting the nodes "i","s"," ","t","e","x","t"," ",...,
 Paul Prescod  - ISOGEN Consulting Engineer speaking for only himself

"Perpetually obsolescing and thus losing all data and programs every 10
years (the current pattern) is no way to run an information economy or
a civilization." - Stewart Brand, founder of the Whole Earth Catalog

xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@ic.ac.uk
Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1
To (un)subscribe, mailto:majordomo@ic.ac.uk the following message;
(un)subscribe xml-dev
To subscribe to the digests, mailto:majordomo@ic.ac.uk the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa@ic.ac.uk)


News | XML in Industry | Calendar | XML Registry
Marketplace | Resources | MyXML.org | Sponsors | Privacy Statement

Copyright 2001 XML.org. This site is hosted by OASIS