1527 2005-07-09 19:12:53 +0000 Grammar for abbreviated step 2005-07-20 17:15:35 +0000 1 1 1 Unclassified XPath / XQuery / XSLT XPath 2.0 Last Call drafts PC Windows XP CLOSED WONTFIX P2 normal --- 1 chamberl chamberl public-qt-comments oldest_to_newest 4467 0 chamberl 2005-07-09 19:12:53 +0000 The syntax for an abbreviated step now looks like this: AbbrevForwardStep ::= "@"? NodeTest NodeTest ::= KindTest | NameTest This allows users to write silly things like this: @comment() which looks for a comment node on the attribute axis. Of course, there is nothing on the attribute axis but attribute nodes, so there is no need for a KindTest following "@" in an abbreviated step. We could eliminate this kind of silliness by changing the grammar as follows: AbbrevForwardStep ::= NodeTest | "@" NameTest NodeTest ::= KindTest | NameTest 4491 1 mike 2005-07-10 08:14:19 +0000 Please note that XPath 1.0 did not have any "natural" way of expressing an empty node-set. It is therefore customary for XSLT 1.0 users wanting an empty node-set (e.g. as a parameter to a template) to write expressions that are guaranteed to select nothing, such as "/.." or "@comment()". The former is actually recommended in the XSLT 1.0 specification, and the latter is suggested in at least one book. Michael Kay 4879 2 chamberl 2005-07-19 16:54:51 +0000 On further thought, it occurs to me that a kind test in the abbreviated syntax can be used to search for attributes of a particular type, as in this example: @attribute(*, xs:date) This use case, together with Mike Kay's comments, prompts me to withdraw my suggestion for a syntax change. If no one objects, I will mark this comment as closed with a resolution of "WONTFIX". --Don C. 5006 3 scott_boag 2005-07-20 14:52:48 +0000 (In reply to comment #2) > @attribute(*, xs:date) I'm not sure what the "@" buys you here. Why is that different from simply attribute(*, xs:date) ? FYI, I've tested your proposal and it works fine. But maybe we should go ahead and leave it alone, since it would be another XPath 1.0 incompatibility, which I would like to avoid. -scott 5010 4 chamberl 2005-07-20 17:14:38 +0000 On July 20, 2005, the Query and XSLT working groups voted to close this comment without change to specifications.