Re: [xsl] Sequences in XSLT 2.0..

[Midsummer Sun <midsummer.sun@xxxxxxxxx>]

Thank you David for a nice explanation. 

Best regards,

When in doubt, use brute force.
-- Ken Thompson

On Mon, 14 Mar 2005 17:18:45 GMT, David Carlisle <davidc@xxxxxxxxx> wrote:
> 
> > Now everything is a sequence.
> > Earlier everything was a node-set.
> 
> not quite true. In XSLT2 everything is a sequence but in xslt1 atomic
> values such as numbers and strings were not in a node set or a sequence.
> 
> One advantage of sequences is that you can store sequences of strings
> etc ("a","b", ....)
> 
> The other is that sequences become first class objects that may be saved
> in variables and re-used. XSLT1 had sequences (called lists there)
> but these were just transient objects "the current node list"
> that could not be stored.
> 
> If you go select="ancestor::*[2]" then just inside the step the current
> node list is the ancestors in reverse document order so [2] selects your
> grandparent, but this could not be stored,
> ,xsl:variable name="x" select="ancestor::*"/>
> selects the unordered set of ancestors then
> select="$x[2]"
> orders that set in document order so [2] selects teh grandchild of the
> document element.
> 
> Similarly inside
> <xsl:for-each select="zzzz">
> <xsl:sort select="mmm"/>
> 
> the current node list is the ordered list sorted by mmm but that list
> can not be saved in order, if you need it again later you have to
> re-sort. In XSLT2 sorted sequences can be saved.
> 
> Other reasons have to do with alignment with xsd schema but they are,
> natutrally:-) almost all bad, but on balance ordered sequences are
> probably a good thing (although perhaps they might have been better
> still if they had allowed sequences of sequences)
> 
> David
> 
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