Subject: Re: check if a node is empty
From: Jeni Tennison <jeni@xxxxxxxxxxxxxxxx>
Date: Thu, 17 Oct 2002 16:49:00 +0100
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Hi Vasu,
> would the following statement
> <xsl:template match="node">
> ....
> <xsl:when test="count(*)=0"> ( to check for empty child elements)
> ----
> </xsl:template>
> be any inefficient ?( was just thinking of other ways to do it
> besides the standard ones you have suggested )
It would be more inefficient (at least with a naive processor) because
the processor would have to visit every child element of the current
node in order to count them. Node visits take time, so avoiding them
is a good idea. On the other hand, that's also the case with a naive
implementation of:
test="*"
However, most processors will rewrite this test to:
test="*[1]"
which only involves one node visit. I believe that Saxon rewrites
count(*) = 0 to boolean(*[1]) as well, actually, so perhaps there's
not much in it...
So try it and see with your favourite processor :)
Cheers,
Jeni
---
Jeni Tennison
http://www.jenitennison.com/
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