Re: [xml-dev] The use of XML syntax in XML Query

Jonathan Robie wrote:

> At 03:25 PM 1/3/2002 -0500, Jonathan Borden wrote:
> >One can always introduce a new/XML syntax, I would favor:
> >
> >3) updating XSLT including XPath 2.0 as the XML syntax 'version' of
XQuery,
> >that is to say any features of XQuery not included in XPath 2.0 should be
> >included in XSLT 2.0 (well it already has element constructors etc). Is
this
> >feasable?
>
> Possibly. But some of this is hard. XSLT tends to construct things top
> down, and XQuery constructs things bottom up, for reasons that make
perfect
> sense in each language, which means the element constructors are
different.

I am not at all sure this is an insurmountable issue, and much depends on
the style of XSLT that is used.

> Updates don't work well in XSLT since it clearly separates the input tree
> from the output tree.

A somewhat long time ago (i.e. circa 2000) I wrote a little XML editor which
compiled itself into XSLT http://www.openhealth.org/editor/. Work on this
was merged into the XUpdate progect of xml:db
http://www.xmldb.org/xupdate/xupdate-wd.html. I think that the XSLT _syntax_
is perfectly capable of _expressing_ updates, and any issues are left to
implementations.

But moreover, most XSLT implementations include a function that casts a
result-set into a node-set, so this issue is well known and hopefully such a
cast operator could be made a standard part of XSLT 2.0. In any case I think
there probably is not a need to have both an XML syntax for XQuery and XSLT
2.0, as query and transform are really two heads of the same coin.

Jonathan

Received on Thursday, 3 January 2002 16:39:43 UTC