- From: Axel Polleres <axel.polleres@deri.org>
- Date: Tue, 15 Sep 2009 17:14:58 +0100
- To: <kifer@cs.sunysb.edu>
- Cc: "Public-Rif-Wg \(E-mail\)" <public-rif-wg@w3.org>
- Message-Id: <BEC329A0-EB84-45C8-9598-0CD47BF9B77D@deri.org>
Michael, we discussed that in the phone conference... and the general opinion was to keep with the easy fix I proposed unless you object. Do you? Thanks, Axel On 17 Aug 2009, at 21:52, Michael Kifer wrote: > i think using lists is a cleaner solution in general > > On Mon, 17 Aug 2009 21:28:27 +0100 > Axel Polleres <axel.polleres@deri.org> wrote: > > > Hi all, > > > > While working on the all-builtins use case, I realize a slight > > error/problem in DTB now with the function: > > > > func:string-join(...) > > > > its xpath/xquery counterpart fn:string-join(...) > > > > takes two arguments: > > - a sequence of strings > > - a "separator" string > > > > now I realize - since this function was introduced when we didn't > heva > > lists in RIF yet, that we seem to have expected a "flattened" list > as > > input, i.e. we give the schemas > > > > ( ?arg1 ?arg2; func:string-join(?arg1 ?arg2 ) ) > > > > ( ?arg1 ?arg2 ?arg3; func:string-join(?arg1 ?arg2 ?arg3 ) ) > > > > ... > > > > ( ?arg1 ?arg2 ... ?argn; func:string-join(?arg1 ?arg2 ... ?argn ) ) > > > > > > Anyways, the semantics is defined in terms of fn:string-join, which > > didn't work so far, but only works with a small fix, i.e. > interpreting > > the first n-1 arguments as the sequence argument of the CPAth/Xquery > > fn:string-join function. "Historically" this is IMO what we meant, > as > > there was no lists. > > > > Thus, I see two options for fixing this: > > > > a) stick with the flattened version, interpreting the first n-1 > > arguments as the sequence argument of the CPAth/Xquery fn:string- > join > > function and the last argument as the separator string. > > > > b) make the function with a fixed arity of 2, the domain of the > first > > argument being a list of strings and the second argument the > separator > > string. > > > > I implemented option a) now, since it is the "least intrusive" > change to > > the current doc, see > > > > http://www.w3.org/2005/rules/wiki/index.php?title=DTB&diff=10665&oldid=10495 > > > > however, b) seems somehow the more natural way to proceed. The > > disadvantage/worry I see with b) is that we might want to implement > > "emulating" sequences by lists as input in other functions as > well... > > Opinions? > > > > Axel > > > > > > > -- Dr. Axel Polleres Digital Enterprise Research Institute, National University of Ireland, Galway email: axel.polleres@deri.org url: http://www.polleres.net/
Received on Tuesday, 15 September 2009 16:15:40 UTC