[XSL-LIST Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: Optimization/error reporting: cardinality checks &

Subject: Re: Optimization/error reporting: cardinality checks & function calls
From: Dimitre Novatchev <dnovatchev@xxxxxxxxx>
Date: Tue, 24 Jan 2006 06:59:34 +1100
cardinality of a function
> I think the understanding is meant to be that an implementation is free to
> skip "evaluation" of an argument, and that the cardinality check is also
free
> to be skipped if the argument as a whole has been skipped.
>
> Am I right in my interpretation?

It seems to me that the return type of the function cannot be
determined without knowing the cardinality of the function -- due to
the fact that different overloads can have different return types.

Therefore, as cardinality would be necessary in general, it cannot be
skipped or ignored.


--
Cheers,
Dimitre Novatchev
---------------------------------------
To avoid situations in which you might make mistakes may be the
biggest mistake of all.



On 1/24/06, Frans Englich <frans.englich@xxxxxxxxx> wrote:
>
> Hi all,
>
> I'm a bit confused about errors & optimizations in XPath/XQuery
> implementations, perhaps someone could help me clear it.
>
> 2.3.4 Errors and Optimization in XML Path Language (XPath) 2.0 says that
> implementations are free to perform arbitrary optimizations(such as
skipping
> evaluation of somekind) as long as 1) The result is identical to when not
> being optimized, except for that errors are possibly not reported; and 2)
> that cardinality errors are still reported.
>
> Section 2.3.4 uses the term "expression", and I presume functions are
> applicable to that discussion(functions are expressions).
>
> Further, in 3.1.5 Function Calls, one can read this:
>
> <quote>
> Argument expressions are evaluated, producing argument values. The order of
> argument evaluation is implementation-dependent and a function need not
> evaluate an argument if the function can evaluate its body without
evaluating
> that argument.
> </quote>
>
> I think the understanding is meant to be that an implementation is free to
> skip "evaluation" of an argument, and that the cardinality check is also
free
> to be skipped if the argument as a whole has been skipped.
>
> Am I right in my interpretation?
>
>
> Cheers,
>
>                Frans

Current Thread

PURCHASE STYLUS STUDIO ONLINE TODAY!

Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced!

Buy Stylus Studio Now

Download The World's Best XML IDE!

Accelerate XML development with our award-winning XML IDE - Download a free trial today!

Don't miss another message! Subscribe to this list today.
Email
First Name
Last Name
Company
Subscribe in XML format
RSS 2.0
Atom 0.3
Site Map | Privacy Policy | Terms of Use | Trademarks
Free Stylus Studio XML Training:
W3C Member
Stylus Studio® and DataDirect XQuery ™are products from DataDirect Technologies, is a registered trademark of Progress Software Corporation, in the U.S. and other countries. © 2004-2013 All Rights Reserved.