Re: calculating relative position in document order

Hi Tom,

(Earlier today Michael Kay answered a message that involved
recommending this library:  http://www.functx.com/functx/ ... so I had
a quick look at functx and it is fresh in my mind.)

These functions are not exactly like your fantasy pseudo code... but I
think there some useful functions that may have help solve your
problem....

For example:
http://www.xsltfunctions.com/xsl/functx_sequence-node-equal.html
http://www.xsltfunctions.com/xsl/functx_sequence-node-equal-any-order.html

If you peruse the functions, I think you'll find many other
interesting/related functions that you may be able to leverage.

(Note: I found the download link difficult to find on the page...
Hint: It's at the top of the page.)

Darcy
On Thu, Oct 16, 2008 at 12:53 PM, tom s <tshmit@xxxxxxxxx> wrote:
> Hi,
>
> I'd like to be able to determine which element is "closer", in terms of document order, to a given element. eg, given two structures containing siblings:
>
>        <a>
>        <b>
>        <c>
> and
>        <b>
>        <a>
>        <c>
>
> I'd like to detect that the second structure is "out of order". In my fantasy pseudo code, I might express the constraint as:
>
> //c[positionEX(preceding::a[1]) > positionEX(preceding::b[1])]
>
> Where my fantasy positionEX() function returns the absolute position of the argument in the document.
>
> Am I missing something, or is implementing this operation in real xpath/xslt much more difficult than it seems it should be?
>
> Thanks in advance for any help...
>
> --T