The 'context()' function would be similar to the 'current()' fuction.
It would recall previous context nodes.
'context(n)' would recall the n-th context node (as found
when propagating
upwards in the predicates of the expression)
e.g.:
'context(0)' is equal to '.'
'context(1)' is equal to the context node as constructed by the
immmediately outer predicate.
...
'context(-1)' would be equal to the context node as found in
the outermost
predicate.
Something like this was in an early draft of XPath 1.0, and was implemented
(IIRC) in WD-xsl, though I've rarely seen it used in practice.
I think the idea of manually addressing the stack of context variables is
very error-prone and counter-intuitive. The proper way to do this is to
declare a range variable. In XQuery you can do this using the "let" clause
of the FLWOR expression; XPath 2.0 has a poor man's version in the "for"
expression, which allows:
$SetA/Element[for $Z in . return $setB/Element[substring-after(.,'.')=$Z]]
In fact you might want to turn the whole thing into an XQuery-like join:
for $Z in $SetA/Element,
$Y in $setB/Element
return
if (substring-after($Y, '.') = $Z)
then $Y else ()
Michael Kay
http://www.saxonica.com/
--~------------------------------------------------------------------
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
To unsubscribe, go to: http://lists.mulberrytech.com/xsl-list/
or e-mail: <mailto:xsl-list-unsubscribe(_at_)lists(_dot_)mulberrytech(_dot_)com>
--~--