Subject: RE: A theory problem From: Kay Michael <Michael.Kay@xxxxxxx> Date: Thu, 28 Oct 1999 15:56:35 +0100 |
This is nice and clean, but it doesn't seem to catch child::A/child::B/child::C. I've been trying to work with a generalisation of your "single-level" property: a path expression has the "peer" property if no node in the set is an ancestor of any other. Then (I think) P / Q is in document order if P is in document order and P has the peer property and Q has the stays-in-subtree property. Saxon 4.7 implemented a rule that the result was ordered if all the steps were downwards, which I now know to be incorrect. Mike > -----Original Message----- > From: James Clark [mailto:jjc@xxxxxxxxxx] > Sent: 28 October 1999 11:34 > To: xsl-list@xxxxxxxxxxxxxxxx > Subject: Re: A theory problem > > > A path expression has the property if > > (a) it doesn't use / and the axis is a forward axis, or > > (b) it is a / expression, and the left hand operand has the > "single-level" property and the right hand operand has the > "stays-in-subtree" property. > > A path expression E has the "single-level" property if and only if for > any context node C, evaluating E wrt C yields a set of nodes all of > which have the same parent. > > A path expression E has the "stays-in-subtree" property if and only if > for any context node C, evaluating E wrt C yields a set of > nodes all of > which are in the subtree rooted at C (ie have C in their > ancestor-or-self axis). > > It's easy to see this is a sufficient condition for the path > expression > to have the property: if x and y have the same parent, and x > is before y > in document order, then any node in the subtree rooted at x is before > any node in the subtree rooted at y. > > XT implements this. > > Kay Michael wrote: > > > > > > A path expression returns a nodeset. There is a "natural order" to the > > result which is obtained by following the steps in a particular sequence. > > For some path expressions the natural order will always be the same as > > document order, for others it will not. Provide an algorithm that examines a > > path expression and determines whether it will always return nodes in > > document order. XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
Current Thread |
---|
|
<- Previous | Index | Next -> |
---|---|---|
Re: A theory problem, david . rosenborg | Thread | RE: A theory problem, Christopher R. Maden |
Re: Remove duplicates from a list, Minita Jha | Date | RE: Apply XSL on HTML/MathML ?, zun |
Month |