I've always been a little frustrated that I rely heavily on equivalences like
preceding::x === ancestor-or-self::*/preceding-sibling::*/descendant-or-self::*
without having what I would consider a formal proof.
Michael Kay
Saxonica
On 26 Jan 2016, at 16:15, Adam Retter
adam(_dot_)retter(_at_)googlemail(_dot_)com
<xsl-list-service(_at_)lists(_dot_)mulberrytech(_dot_)com> wrote:
Given two simple XPaths, say:
1. //w
2. /x/y/z/w[@a = 'v']
As a human I can very easily tell without evaluating the expressions
that (2) will return a subset (or the same set) of the results that
(1) would return *should* they both be evaluated.
My goal here is given any two simple arbitrary XPaths expressed as
strings, and without evaluating them against a context, to determine
whether one would return a subset of the results of the other.
I wondered if there might be an algorithm or library that someone
already had or has written which might be able to give me the answer?
I realise that I can only probably cover a subset of XPath itself, but
it is only the path steps with predicates which I am interested in.
Ideally I am looking for something in Java.
--
Adam Retter
skype: adam.retter
tweet: adamretter
http://www.adamretter.org.uk
--~----------------------------------------------------------------
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
EasyUnsubscribe: http://lists.mulberrytech.com/unsub/xsl-list/1167547
or by email: xsl-list-unsub(_at_)lists(_dot_)mulberrytech(_dot_)com
--~--