- From: <Patrick.Stickler@nokia.com>
- Date: Wed, 14 Nov 2001 22:23:46 +0200
- To: bwm@hplb.hpl.hp.com, connolly@w3.org
- Cc: w3c-rdfcore-wg@w3.org
> Pat in a later post proposed to distinguish the proposal I > originally labeled X > as URV and use X to denote the proposal in: > > > http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2001Nov/0303.html > The distinction is useful and I suggest we consider both. Here is a revised version of Pat's excellent summary table including URV (or just U) and X proposals: U S DC P P++ X CONS requires literals as subjects x requires change to MT x x x requires DTs to be 'proper' x x (x) requires user conform to idiom (x) x x (requires literals to be typed) x x cannot express 'clashing' types (x) x (x) (x) PROS fully general x x conforms to current usage (x) x x x allows free type merging x ? compatible with DAML x x ? (x) --- Note that I've qualified the con 'cannot express clashing types' for the U(RV) proposal as it is possible to define multiple mappings from URV schemes to data types, including mappings which have incompatible lexical space or precision. Though the degree to which mutiple types associated with a URV can "clash" is much more limited than the other proposals. The X proposal doesn't require literals as subjects per se as all statements are defined in terms of node identity, irrespective of the node type or label. Any node can be a subject. The X proposal only requires DTs to be 'proper' in terms of value space, not lexical space. The X proposal 'conforms to current usage' insofar as it reflects the current model for reification of statements, and treats the resource-centric graph (such as employed by the other proposals) as a view derived from that underlying statement-centric representation. As far as I can tell, the X proposal should be compatible with DAML, though I've qualified that as needing verification. The same should also be true for the U proposal, in that since typed literals become resources with URI Ref identity, it shouldn't break anything, though data type remains implicit. I'm not 100% sure what is meant by 'free type merging' so don't know if the X proposal does or does not have that quality. -- Hope the above is helpful. Flame at will... ;-) Cheers, Patrick
Received on Wednesday, 14 November 2001 15:24:03 UTC