- From: Michael Kay <mhk@mhk.me.uk>
- Date: Fri, 25 Feb 2005 15:51:13 -0000
- To: "'Elliotte Harold'" <elharo@metalab.unc.edu>, <public-qt-comments@w3.org>
> I'm concerned about the last two sentences of each of these > paragraphs. > > In XOM, in XPath 1, I've found it useful to query trees with > no document > nodes above them by inserting a sort of pseudo-document node. We did consider that approach, but decided that specifying it in such a way that tidied up all the possible loose ends would be hopelessly complicated. (As I know from experience, coding something is often a lot easier than specifying it rigorously enough to satisfy a W3C WG). Another approach would be the device used in specifying XSLT 2.0 patterns: the "child-or-top" axis. But again, it's hardly elegant and extending it to the demanding space of full path expressions would be quite troublesome. > This makes expressions like /a/b/c meaningful, whether or not the > context node is in a document. I think it's actually a good idea in a multi-document environment to encourage users to put a variable at the top: $x/a/b/c. There's still scope for confusion, of course, as to whether $x refers to a document node or an element node. It's also possible, of course, to find the root of any tree using the root() function. The WGs have given quite a lot of thought to this subject: we're aware there are usability pitfalls in this area, but decided that making "/" on orphan trees an error would put some kind of fence around the problem that stopped users falling in unawares. Michael Kay (personal response).
Received on Friday, 25 February 2005 15:52:08 UTC