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

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


sandygao@ca.ibm.com changed:

           What    |Removed                     |Added
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                 CC|                            |sandygao@ca.ibm.com




------- Comment #1 from sandygao@ca.ibm.com  2006-09-08 20:53 -------
I was also thinking about expanding the subset. My focus has been:
- Allow "quantified" expression (some/every ... satisfies ...) and possibly
"if" expressions (if ... then ... else ...) (it's unfortunate there isn't a
short form like if ... then ...)
- Allow more than attributes in predicates (hoping that it's still streamable)

Now how are you suggesting we expand it?
- not/count: in XPath 2.0, I think they became fn:not and fn:count, which are
allowed by the grammar. Hum... not sure whether it still allows XPath 1.0
functions without the namespace.
- About casting: I think maybe it's OK to omit xs:string(). Treat it as the
default. We can also treat integer literals in the same way. Or we can go to
the extreme and omit all constructor functions and implicitly cast the string
value to the value space of the other operand.
- Comparison: I think we have to use the 2-letter operators to match XPath 2.0
semantics
- About arithmatic and promotion/casting: this is the discussion we had and I'm
inclined to say "no" for now.

Also note that for "Require somewhere", we only allow ".//buyer" and not
"//buyer". To make sure "buyer" appears somewhere in the tree, you only need
.//buyer
which is equivalent to
fn:count(.//buyer) > xs:int('0')

Received on Friday, 8 September 2006 20:53:48 UTC