RE: XQuery -- Reinventing the Wheel?

[Evan Lenz <elenz@xyzfind.com>]

Jonathan Robie wrote:
> First, simple queries are simpler in XQuery. For
> instance, an XPath 2.0 expression that uses the
> abbreviated syntax is also a valid query by itself.
> This is not true of XPath. Your document
> http://www.xmlportfolio.com/xquery.html incorrectly
> labels XPath expressions as XSLT, but an XSLT processor
> will not process your examples unless you place them
> in a template.

Jonathan, these examples are labeled XSLT, because they make use of the
document() function which is an XSLT-specific extension to XPath. *Of
course* an XSLT processor won't process these as such. A solution to this
would hardly be the most creative endeavor yet seen by the W3C. (Define a
stand-alone XPath expression to be an implicit copy-of, generate the query
automatically, I don't care.) Straw man #1. After all, this is where we
agree! The reuse of XPath is good, but it does not go far enough.

Your inline XSLT examples completely miss the point. The reason they are
included in my paper is to identify the problem, not to propose a particular
solution--the problem of course being that the semantics, the data model,
the processing model, whatever you want to call it, of XSLT and XQuery are
very, very similar, but not the same. There is no good reason why the
semantics of XQuery should not coincide with that subset of XSLT that might
succinctly be called XSLT's "down-reference pull" (as opposed to the "push"
of template rules, and the random access of the other XPath axes). I think
the debate over syntax is starting to cloud this deeper issue.

Evan