RE: [xsl] Passing sort criteria as a paramter

On Fri, 2002-01-25 at 14:29, Kay, Michael wrote:
> Thanks for sending this. The question of whether to provide dynamic
> evaluation of XPath expressions (for example, a function like
> saxon:evaluate() and xalan:evaluate() is under active discussion in both the
> XSL and XPath groups at the moment. At present, I'm not optimistic that it
> will make it. We do understand the requirement, but it causes considerable
> problems for implementors of XSLT compilers, and there are also some tricky
> technical problems in defining a suitable specification - for example, how
> should namespace prefixes in the dynamic XPath expression be resolved?

I'm having a lot of trouble seeing this as a tricky issue.  To me there
are 2 solutions:

1) Simply inherit namespace mappings from the point of use fo the
dynamic expression

2) Provide a mechanism for setting up context, including prefix
bindings.

(2) would be a bit hard to spell unless dynamic expressions are defined
in an extension element rather than function, but I think this is OK.

Note, however, that I understand that optimizations and static compiler
design are powerful arguments against making dynamic expressions part of
XSLT's core.  Could XSLT consider a "level" system similar to DOM's
where perhaps dynamic expression is in level 2?


-- 
Uche Ogbuji                               Principal Consultant
uche.ogbuji@fourthought.com               +1 303 583 9900 x 101
Fourthought, Inc.                         http://Fourthought.com 
4735 East Walnut St, Boulder, CO 80301-2537, USA
XML strategy, XML tools (http://4Suite.org), knowledge management

Received on Friday, 25 January 2002 19:03:25 UTC