Re: [xsl] OR expr with node sets

[David Carlisle <davidc@xxxxxxxxx>]

> The above uses an union expression, not an or expression. There's a difference.
> 
>   <xsl:if test="foo | bar">
> 
> collects two node-sets, creates an union and then casts the combined node-set to a boolean.
> 
>   <xsl:if test="foo or bar">
> 
> collects two node-sets, casts both of them into booleans and then makes an OR comparison between the resulting booleans.
> 

That's true according to the way things are specified, although the end
result is always the same so an actual implementation may well do the
same thing in both those cases (and in both cases not generate the whole
set, but stop looking as soon as it finds any node, as it knows that it
is in a boolean context).

David

________________________________________________________________________
This e-mail has been scanned for all viruses by Star. The
service is powered by MessageLabs. For more information on a proactive
anti-virus service working around the clock, around the globe, visit:
http://www.star.net.uk
________________________________________________________________________