Re: [xml-dev] XPath 1.5? (was RE: [xml-dev] typing and markup)

From
Jeni Tennison <>
To
Michael Kay <>
Date
2002-05-08T16:55:36Z
ID
<>
Thread
Re: [xml-dev] XPath 1.5? (was RE: [xml-dev] typing and markup)
Hi Mike,

>> I agree that empty elements are a special class of those, but is the
>> time it takes to analyse the schema to work out whether a type is
>> empty likely to give a significant speed advantage over just checking
>> whether the element has any children? It might if the document had
>> huge numbers of those elements, or if the schema analysis only had to
>> occur once. Otherwise, it's much less clear cut.
>
> There is one example in XSLTMark where schema knowledge could make a
> dramatic difference. It effectively does
>
>   <xsl:template match="row[id='0432']">
>     <html>
>       .. stuff ..
>     </html>
>   </xsl:template>
>
>   <xsl:template match="text()"/>
>
> If you know that a row cannot contain another row then you can skip
> processing 99.99% of the data.

Do you mean if you know that the document cannot contain another row
with the same id, or did you mean if you know that a row cannot
contain another row? I'm missing something about what optimisations
it's useful to make in XSLT, if you meant the latter?

Cheers,

Jeni

---
Jeni Tennison
http://www.jenitennison.com/