Re: xpath filtering extension function called too many times

Thanks for your fast reply Michael :)

Hmmm... I am not sure that I understand why the processor needs to call 
dummy() more than once, since the [1] filter clearly states "give me 
only the first node".
I would expect that the processor will call dummy() until it will 
receive a true then stop because of the [1] filter.

I wonder if there is some way of re-writing these expressions in order 
to get the desired result?

Thanks again,
Adrian.

On 22/06/2010 12:02, Michael Ludwig wrote:
> Adrian Herscu schrieb am 22.06.2010 um 11:33 (+0300):
>
>>    <xsl:template match="/document">
>>      <document-report>
>>        <xsl:for-each select="descendant::section[utils:dummy(true())][1]">
>>          <section-report ref="{@ref}"
>> proc-ref="{ancestor::chapter/@name}" />
>>        </xsl:for-each>
>>      </document-report>
>>    </xsl:template>
>
>> In this case the console will show that dummy() was called *once*
>
> My guess is that the processor, having established that the [1] filter
> eliminates all but the first node, optimizes the other calls away.
>
>> The problem is with the variants of
>> descendant::section[utils:dummy(true())][1]:
>>
>>   1. xsl variables:
>>
>> <xsl:variable name="sections" select="descendant::section" />
>>
>> and then use this XPath expression instead
>>
>> xalan:nodeset($sections)[utils:dummy(true())][1]
>>
>> then the dummy() function will be called 4 times (while the output xml
>> will remain the same) !
>
> The processor doesn't optimize this expression?
>
>>   2. paths with more than one fragments:
>>
>> (chapter/section[utils:dummy(true())])[1]
>> (chapter/section)[utils:dummy(true())][1]
>> ((chapter/section)[utils:dummy(true())])[1]
>>
>> in these cases the dummy() function is called 4 times too (while the
>> output xml still remains the same) !
>
> The processor doesn't optimize these expressions either?
>