- From: Michael Kay <mhk@mhk.me.uk>
- Date: Tue, 30 Aug 2005 23:28:31 +0100
- To: "'Parag Tijare'" <parag@almaden.ibm.com>, <www-ql@w3.org>
- Message-ID: <E1EAEav-0006lD-Rf@maggie.w3.org>
XPath does not have a QName literal. If function F takes a QName as its argument, then you can call it as, for example F(node-name($n)) or F(QName("uri", "local")) or F(resolve-QName("xsi:type", .)) but you can't call it as F(app:type1) except in the special case where evaluating the path expression app:type1 and atomizing the result gives you a QName. An element test is a special construct for a number of reasons, one of which is that types are not first class objects in XPath: you can't pass a type to a function, nor return a type from a function. Michael Kay http://www.saxonica.com/ _____ From: www-ql-request@w3.org [mailto:www-ql-request@w3.org] On Behalf Of Parag Tijare Sent: 30 August 2005 22:09 To: www-ql@w3.org Subject: functions with QName argument(s) in XPath Is it possible to define an XPath function that takes type name or node name as arguments, something along the lines of "Element Test" (which is a built-in construct) in XPath. If yes, wouldn't there be a conflict in interpreting the argument? e.g. consider a hypothetical function "foo" that is intended to take a type name as its second argument. in /A/B/foo(C, myapp:Type1), would XPath semantics require that the second argument be interpreted as being the child node of /A/B rather than a type name? I wonder if "Element Test" is designed as a built-in construct rather than a function for this reason. Any ideas? Thanks, Parag Tijare
Received on Tuesday, 30 August 2005 22:28:43 UTC