Comments on http://www.w3.org/TR/xquery-operators/

The XPath type functions comment(), node(), text(), processing-instruction(),
node(), id(),  do not appear to be described in this document.  These
functions may occur not just as a qualification in an XPath expression
but as stand-alone functions within predicates that test the type of the
context node.  As such stand-alone functions they need to be both described
in this standards document and bound to an explicit namespace, so that the
developer knows their behaviour and what their binding is. 

These functions should also be described in Appendix B.. Compatability with
XPath 1.0.

The prefixes fn: op: xs: and xdt: are not explicitly mapped to namespaces.
While the bindings can be inferred I think a standard should not invite
such inferences.

In section 5.1 it is stated that "The semantics of the constructor
function xs:TYP (xdt:anyAtomicType) are identical to the semantics of
"cast as xs:TYPE(xdt:anyAtomicType)".  This begs the question of whether
such functions must be implemented/may be implemented/or like those functions
bound to the op: namespace will not be implemented.  This issue should be
resolved since it impacts upon the portability of XQuery that employs
functions in the xs: and xdt: namespaces, rather than a cast.

Omitting these functions from those that must be implemented has the attractive
property that all XQuery function which "must be implemented" reside in the
fn: namespace.

I hope my comments are viewed as constructive ones..

Regards, Ian Davis

Received on Tuesday, 12 August 2003 12:40:43 UTC