Re: [xsl] Why is the variable and regex slow in saxon and fast in regex Buddy?

Subject: Re: [xsl] Why is the variable and regex slow in saxon and fast in regex Buddy?
From: Alex Muir <alex.g.muir@xxxxxxxxx>
Date: Tue, 28 Sep 2010 12:44:43 +0000

I found something quite interesting which may help further understand the

Independently none of the following variable takes long to process,
such that when  I no longer chain the variables together but just run
the template calling only one variable and comment out the others the
time to run is short.

   <xsl:variable name="title"

     <xsl:variable name="titleBraketedTextRemoved"

     <xsl:variable name="titleNumberRemoved"

     <xsl:variable name="titleStripPunctuation"

     <xsl:variable name="titleStopWordsRemoved"

As the variables are combined together they take more and more time to
execute and finally if all together they do not stop running.

So initially I was wrong to suggest that the titleBraketedTextRemoved
variable was causing the problem. It's just that the problem is
exacerbated when I finally add that variable into the chain of

I reduced the size of the input file so that the $title contains one
small line of text in order to get an idea on the profiling however
the processing does not complete.

I'll have to talk to my client later today before posting the full code.



On Mon, Sep 27, 2010 at 7:54 PM, Michael Kay <mike@xxxxxxxxxxxx> wrote:
>  I don't know - they are both, I think, using the Java regular expression
> engine underneath. It may be a function of how you are measuring it. It
> could be that the cost is dominated not by the cost of evaluating the
> but by the cost of checking that it conforms to the XPath rules. Did you
> a Java profile to determine where the time is being spent?
> Michael Kay
> Saxonica
> On 27/09/2010 7:21 PM, Alex Muir wrote:
>> HI,
>> I'm unable to figure out why this regex is so very time consuming such
>> that it does not end in oxygen but works quickly in regex buddy on the
>> same content.
>>     <xsl:variable name="BraketedTextRemoved"
>>        select="replace($title,'\([^\)]*\)','')"/>
>> I'm just trying to remove content with brackets ( dfd234**#*$#*$#fdfd )
>> Running on vendor="SAXON from Saxonica" version="2.0"
>> Any Ideas?
>> Thanks
>> Alex

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