I'm looking forward to the simple mapping operator in XPath 3.0: https://www.w3.org/Bugs/Public/show_bug.cgi?id=12951
So here's the futuristic alternative #4: $order!coupon-code!looup-coupon-code(.) With "/", the order should always be document order, but when the nodes come from multiple documents, you can get bit by the fact that document order between document nodes is implementation-dependent, and is probably different than your original processing order. The other thing "/" does is remove duplicates, which is possibly not what you want. Evan On 1/10/12 1:59 PM, "Ron Hitchens" <r...@ronsoft.com> wrote: > > Yeah, I discussed the XPath function step in >my earlier response, and Hans-Juergen mentioned >it to, below. > > But if order matters, beware. The XPath >function step alternative may not evaluate in the >same order as the nodes being selected by the XPath. >I've been bit by that a few times. > >On Jan 10, 2012, at 9:51 PM, David Lee wrote: > >> Alternative 3 >> >> $order/coupon-code/looup-coupon-code(.) >> >> >> Sent from my iPad (excuse the terseness) >> David A Lee >> d...@calldei.com >> >> >> On Jan 10, 2012, at 1:29 PM, Hans-Juergen Rennau <hren...@yahoo.de> >>wrote: >> >>> Hi Ron, >>> >>> thank you very much for illustrating the potential usefulness of >>>function mapping! >>> >>> Certainly this is a matter of personal taste, but just this remark: >>>although the use of function mapping makes the code especially compact, >>>I definitely prefer the FLWOR alternative (or the function step >>>alternative), which makes looping explicit and thus avoids the risks of >>>unintended looping and (worse) of unintended omission of processing. I >>>think the code is safer and, yes, cleaner, if one remembers that >>>function mapping depends on the repective parameter to be declared as a >>>single item sequence type, which means that the function invocation >>>cannot be recognized to be a mapping invocation: the parts producing >>>the looping are separate, one being the invocation, one being the >>>signature. I regard this as a kind of obscurity better to be avoided. >>> >>> And the difference in code length is minimal: >>> >>> alternative #1 (function mapping) >>> lookup-coupon-code ($order/coupon-code) >>> >>> alternative #2 (FLWOR) >>> for $c in $order/coupon-code return looup-coupon-code($c) >>> >>> Hans-Juergen >>> >>> Ron wrote: >>> "Function mapping can actually be very handy, you >>> shouldn't just automatically turn it off and forget >>> about it." >>> >>> _______________________________________________ >>> General mailing list >>> General@developer.marklogic.com >>> http://developer.marklogic.com/mailman/listinfo/general >> _______________________________________________ >> General mailing list >> General@developer.marklogic.com >> http://developer.marklogic.com/mailman/listinfo/general > >--- >Ron Hitchens {mailto:r...@ronsoft.com} Ronsoft Technologies > +44 7879 358 212 (voice) http://www.ronsoft.com > +1 707 924 3878 (fax) Bit Twiddling At Its Finest >"No amount of belief establishes any fact." -Unknown > > > > >_______________________________________________ >General mailing list >General@developer.marklogic.com >http://developer.marklogic.com/mailman/listinfo/general _______________________________________________ General mailing list General@developer.marklogic.com http://developer.marklogic.com/mailman/listinfo/general
