[Bug 3673] revisit (and enlarge) XPath subset for assertions?

http://www.w3.org/Bugs/Public/show_bug.cgi?id=3673





------- Comment #2 from mike@saxonica.com  2006-09-27 18:00 -------
Here are some other things which I would like to say, but can't:

(1) events must be in chronological order

every $x in event, $y in event satisfies if $y >> $x then $y/date >= $x/date

(2) currency must be one of the currencies in http://example.com/currencies

. = doc(http://example.com/currencies)/currencies/currency

(3) events must not be in the future

date <= current-date()

(4) date must not be a Sunday

(5) height must be a multiple of 0.25

I'm even finding it difficult to write basic co-occurrence tests such as

if (@a > 0) then exists(@b)

I think there are workarounds for most of these within the proposed subset, but
some of them are unnecessarily tortuous, for example

not(@a gt 0 and not(@b))

The restrictions are so arbitrary that it's going to be very hard for users to
remember them, let alone to learn how to work around them.

Michael Kay

Received on Wednesday, 27 September 2006 18:00:33 UTC