- From: Dave Beckett <dave.beckett@bristol.ac.uk>
- Date: Tue, 30 Jan 2001 11:35:16 +0000
- To: www-rdf-logic@w3.org
I'll reply to this bit of the message since it seems like an appropriate place to give my comments based on stuff I've been doing with Redland[1] and Rapier[2]. >>>"King . Dany" said: <snip/> > Syntactically however, it is... mostly (discrepancies: 1. RDF is requires > acyclic subclass relations, DAML+OIL allows cyclic subclass relations; 2. > DAML+OIL requires one syntax for cardinality to avoid exposed content, thus > other equivalent and legal RDF syntaxes are illegal for DAML+OIL > cardinality; 3. RDF allows only one range restriction per property, DAML+OIL > allows multiple; 4. the "daml:collection" doesn't exist in RDF). Therefore, > with such vast differences in semantics and a ever growing syntactic > divergence, how can backward compatibility be an issue? <snip/> 1. acyclic/cycle class relations/RDF Properties I need to know which one to give optimise for. I assert without evidence that asking typing/classing questions will be very common for RDF/RDFS systems and applications of them and they need to be optimised and have good APIs. 2. cardinality 3. range/domain Not proposing to do anything special for these at present. 4. daml:collection When designing my Rapier[2] parser, I designed support for other types of parseType and collections (class of things that include rdf:Seq, rdf:Bag, rdf:Alt), assuming that some people would need this since it is commonly agreed the current container stuff is horrible. I haven't finished implementing this support yet. Implementation details: I currently propose to allow unknown parseType values to be handled in three ways - 1) Return a string of original content including <>s etc, 2) pass on XML SAX events, 3) form as new XML content with any required namespaces defined locally. For collections, there will be an API for the application to register / implement the collection methods when a collection resource type is found and matches some [R]->rdf:subClassOf->[new-collection-uri] statement. The latter may not be necessary for most applications if the collections interpretation in [3] is used. Dave Institute for Learning and Research Technology (ILRT), http://www.ilrt.org/ [1] Redland - http://www.redland.opensource.ac.uk/ [2] Rapier - http://www.redland.opensource.ac.uk/rapier/ [3] A Proposed Interpretation of RDF Containers - http://www-uk.hpl.hp.com/people/bwm/rdf/issues/containersyntax/
Received on Tuesday, 30 January 2001 06:35:17 UTC