- From: Michael Kifer <kifer@cs.sunysb.edu>
- Date: Tue, 10 Jun 2008 13:15:59 -0400
- To: Jos de Bruijn <debruijn@inf.unibz.it>
- Cc: Rule Interchange Format Working Group WG <public-rif-wg@w3.org>
This makes iriToString a multivalued function (i.e., the same iri has several string interpretations). Is this what we want? --michael On Tue, 10 Jun 2008 16:40:04 +0200 Jos de Bruijn <debruijn@inf.unibz.it> wrote: > > See [1] and preceding the messages in the thread for a description of > the semantic problems. In [1] I also proposed a casting predicate that > seems to work. > > In summary, the biggest semantic challenge in casting IRIs to strings is > that several different IRIs may be mapped to the same string. The > following was my proposal: > > "Let I be an interpretation, let u be an element in the domain of I, and > let {i1, ..., in} be the set of IRIs that denote u, i.e. for each ij (1 > <= j <= n), IC(ij)=u. IR(iriToString)(u,"ij")=t for (1 <= j <= n); > IR(iriToString)(u,s)=f for every element s not in {"i1", ..., "in"}." > > The rule set > iriToString("b"^^rif:iri,"b"^^xsd:string) > > is satisfied in every RIF interpretation. > > I think this predicates should be sufficient for most of the use cases. > > > Best, Jos > > Rule Interchange Format Working Group Issue Tracker wrote: > > > > ISSUE-61 (IRI-Casts): Casting to/from rif:iri [DTB] > > > > http://www.w3.org/2005/rules/wg/track/issues/ > > > > Raised by: Christopher Welty > > On product: DTB > > > > It is clear users of RIF dialects such as BLD will want to be able to convert (cast) instances of rif:iri to/from other datatypes, in particular strings and possibly rif:text. > > > > In general, a casting mechanism is not present in DTB and should be added. > > > > > > >
Received on Tuesday, 10 June 2008 17:16:56 UTC