- From: Sergey Melnik <melnik@db.stanford.edu>
- Date: Mon, 12 Feb 2001 12:08:41 -0800
- To: RDF Interest Group <www-rdf-interest@w3.org>
Following the recent discussion on wrt syntax and namespaces I'd like to mention the internal data model based on RDF that I'm using in my research: Let U be the Unicode alphabet and U* the set of strings defined over U. The set of entities E and the set of statements V are defined using the following recursive definition: 1. U*xU* is subset of E (any tuple consisting of two strings is an entity; the first string of the tuple is called namespace of the entity, the second string is referred to as name of the entity) 2. ExExE is subset of V (every tuple of three entities constitutes a statement) 3. V is subset of E (every statement is an entity) A subset of V is called "model". Without reification, E=U*xU* and V=E^3. The set of literals L is defined as L = {"urn:rdf:literal"} x U* (i.e. literals are resources and can be used as subjects of statements). Other primitive data types are handled similarly, e.g. ("urn:rdf:literal","5") != ("urn:rdf:integer","5"). Notice that namespaces are first-class citizens. Resource ("xyz","") 'reifies' namespace "xyz", so that statements about primitive classes like the class of literals are possible. The above data model subsumes the RDF model defined in M&S 1.0. Sergey P.S.: since Oct 2000, RDF API (http://www-db.stanford.edu/~melnik/rdf/api.html) supports namespaces as part of the model, so that both parser and serializer included in the API can handle resources like ("http://www.w3.org/1999/XMLSchema","date") correctly. -- E-Mail: melnik@db.stanford.edu (Sergey Melnik) WWW: http://www-db.stanford.edu/~melnik Tel: OFFICE: 1-650-725-4312 (USA) Address: Room 438, Gates, Stanford University, CA 94305, USA
Received on Monday, 12 February 2001 14:47:52 UTC