RE: [xsl] Content constructors and sequences

Subject: RE: [xsl] Content constructors and sequences
From: "Kevin Jones" <kjouk@xxxxxxxxxxx>
Date: Thu, 10 Jan 2002 16:16:15 -0000
Thanks Jeni for the detailed response. I should declare that I very familiar
with how  1.0 processors work (just to save you being so explicit in
responses if you want, I know how long they can take to write.)

>
> First, what does it mean to copy a simple typed value into a tree (by
> tree I'm assuming you're specifically meaning node trees as in the
> XPath data model, not a more general 'tree' data type that, since
> XPath doesn't have that concept)?

Yes, more specifically as in the 1.0 RTF type. I misread the how copy-of
will handle sequences of simple values in 2.0 so there will only be one text
node with the concatination of the values and seperators. Not that I
particularly think it has to be that way, but I guess it is consistent with
how documents are normally constructed although at odds with what happen if
you used individual value-of instructions on the sequence.

> The second problem is more significant. One of the features of node
> sets (and node sequences), what enables us to work with them in fact,
> is that they do not contain *copies* of the nodes, but the nodes
> themselves. This means that you can take a node from a sequence and
> find out its ancestors and siblings in the document that it came from
> - those don't change when you put it in a sequence.

This was what I missed in the original post. I hand't twigged you want this
so you could process a sequence of original nodes later. To rephrase it in
very basic 1.0 terms you want to use the syntax normally reserved for RTF
creation to create a Nodeset.

> It would certainly be interesting to see a proposal that made these
> two extensions to the the data model - added simple typed value nodes
> and reference nodes. This would enable documents to hold simple typed
> values and references to nodes from other documents, which would mean
> XSLT could do the same "sequence manipulation" as XPath has to now.

This appears to me, a much more natural approach to the problem and what I
was refereing to when I said,

> > I would like to see sequences in XSLT, but I don't think putting
> > them in along side trees is the natural approach. More as an
> > integral part of the tree structure.

It looks like you can do it for simple values (via text nodes, assuming they
were not merged) but without something like reference nodes you are stuck. I
just find it hard to get past thinking that there is enough trouble with the
difference between RTF and Nodeset without complicating this area further,
but then I don't spend that much time actually writing stylesheets.

Thanks,
Kev.



_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com


 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list


Current Thread