Saxon

Legacy ID: #7759603 Legacy Poster: Michael Kay (mhkay)

This forum is intended for questions specific to the Saxon product: a good place for general XSLT and XPath coding help is the xsl-list at mulberrytech.com (although you're actually in XQuery territory here, for which there is another list - talk at x-query.com). The "/" operator means "evaluate the rhs operand once for every item in the sequence produced by evaluating the lhs operand, with that item as the context item". So $x2/rec/local-name($elem) means evaluaye local-name($elem) once for every element in $x2/rec. There is only one element in $x2/rec, so local-name($elem) gets evaluated exactly once, and returns, of course, the local name of the node in variable $elem. It's usually rather pointless to have an expression on the rhs of "/" than doesn't depend on the context item, but it's not banned: there are plenty of expressions that are pointless, like $x * 1, and it's a general principle of modern language design that being pointless is not in itself justification for making something illegal. You were thinking, of course, that the local name of $elem would be used as a NameTest in the next step of the path expression. Well, the language doesn't work that way: you can't generate bits of syntax on the fly by evaluating expressions, and then have that syntax parsed and evaluated again. It's surprising what people sometimes expect: there was a post on the Wrox forum today where someone wanted to use a variable containing the string "and" or "or" in place of the actual operator. I guess there are some completely interpretive shell languages that allow that, but XPath isn't one of them.

Legacy ID: #7761271 Legacy Poster: Stefan_E (stefane1)

Hi Michael, thanks for your detailed reply. Your rhs/lhs explanation makes a lot more sense than much of what I've read online and in the XQuery book :-). Once such conceptual things are clear, the rest probably goes down more easily ...