[Versa] Question about query

[Uche Ogbuji]

On Sun, 2005-09-04 at 13:25 -0600, Michael Olson wrote:
> >>
> >> If we don't want it to be  query, but a "pattern", then we would have
> >> to change the spec so the above two queries are not valid as top level
> >> queries, but only valid in filter, traverse, and function calls.
> >>
> >>
> >> As I said in a previous email, it is on my "need" list to support  
> >> these
> >> queries.  If we remove them, then I will have to use an extension
> >> function.
> >
> >
> > I don't think you would need an extension function to do "'foo'" to
> > return all strings in the model that are 'foo', you could do:
> >
> > filter(type(xsd:string),"contains('foo')")
> >
> 
> Sure, and with support for literal based functions, I could find all  
> foos with a certain data type, or language.
> 
> It will just be a lot quicker (implementation wise) to do this as a ext  
> function.

Quicker to implement or quicker for an impl to compute?  As for the
latter, that's what optimizers are for, and surely we're not doing
premature optimization in a language spec?


-- 
Uche Ogbuji                               Fourthought, Inc.
http://uche.ogbuji.net                    http://fourthought.com
http://copia.ogbuji.net                   http://4Suite.org
Use CSS to display XML, part 2 - http://www-128.ibm.com/developerworks/edu/x-dw-x-xmlcss2-i.html
XML Output with 4Suite & Amara - http://www.xml.com/pub/a/2005/04/20/py-xml.html
Use XSLT to prepare XML for import into OpenOffice Calc - http://www.ibm.com/developerworks/xml/library/x-oocalc/
Schema standardization for top-down semantic transparency - http://www-128.ibm.com/developerworks/xml/library/x-think31.html