Re: [xsl] Can sets have order?

Subject: Re: [xsl] Can sets have order?
From: David Carlisle <davidc@xxxxxxxxx>
Date: Fri, 2 Feb 2001 13:29:28 GMT
> The node set is exported, e.g., as ASCII representation, and, e.g.,
> put as a file on the Web or sent to somebody who should use it.
> Then, in this file, the two nodes which are deep-equal are exchanged.

er that may be what you mean't, but it isn't what you said.
That isn't exchanging nodes, that's editing an ascii file.

So what you are saying is that if I take

<foo> <x/> </x> </foo>

and edit the above to swap the two x to produce

<foo> <x/> </x> </foo>

(yes, I did swap them) then the resulting file will produce something
identical to XPath.

Yes this is true. But nothing to do with exchanging nodes or node
identity. I don't think anyone will disagree with your statement
if that is what you meant.

> Yes, but only due to the use of an additional function.

but what is xpath if not a bunch of such functions.
If the nodes were indistinguishable (as you claim) how could a function
distinguish them?

> Thus, I argued that XML node sets - without any additional information 
> due to internal representation - are multisets.

No. The value produced by generate-id() is an implementation detail
but the fact that it is unique is not, it is part of the definition of
the XPath tree model. Thus the Xpath tree model as part of its
specification, not as an implementation detail, ensures that every
node is uniquely identified. and Node sets may not contain more than one
copy of any node with this identifier, as they are sets.


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