- From: <Patrick.Stickler@nokia.com>
- Date: Thu, 15 Nov 2001 11:53:48 +0200
- To: Graham.Klyne@MIMEsweeper.com
- Cc: w3c-rdfcore-wg@w3.org
> -----Original Message----- > From: ext Graham Klyne [mailto:Graham.Klyne@MIMEsweeper.com] > Sent: 14 November, 2001 16:48 > To: Stickler Patrick (NRC/Tampere) > Cc: w3c-rdfcore-wg@w3.org > Subject: Re: The X Datatype Proposal > > > Patrick, > > I've taken a look through your "X datatype" proposal, ... > > (Hint: if > you think I am missing a key point, note that Pat has been > able to sketch > his basic ideas in less than, or about, a page of text; I hardly aspire to be able to express myself as well or as concisely as Pat! ;-) > if > you your key > ideas likewise cannot be likewise distilled I'm going to have > a really hard > time accepting that they are any better that what we already have.) I just wanted to point out that (a) the majority of the content of my proposal was discussion of the problem space, and lengthy examples, not definition of the model itself (b) the model was not expressed mathematically, and thus would not have as concise a definition as Pat might achieve Here is the condensed definition of the model itself, in about a page (or less ;-) excluding the explanation of the graph notation used for the examples. -- The X Proposal: The following is a graph representation which is based on the reified statement as its foundational construct and may be considered as a layer below the current resource-centric graph model. Types (classes) of graph nodes: SNode Statement Node UNode URIRef Labled Node LNode Literal Labled Node BNode Blank Node Facets (properties) of graph nodes: ID SysID type (SNode|UNode|LNode|UNode) label for UNode, URI Reference for LNode, RDF Literal for SNode, URI Reference (optional) subject for SNode, SysID predicate for SNode, SysID object for SNode, SysID Key points: 1. The values of subject, predicate, and object facets are graph nodes, not their labels or the resources denoted by those labels. 2. Data types are bound to literals by making statements about the LNode representing the literal property value. 3. This representation is not based on triples, but could be seen as a model by which triples are defined. Graph notation: A node is represented by a comma separated sequence of ID, type, and (if present) label which is surrounded by square brackets. The type is represented by an uppercase character S, U, L, or B denoting an SNode, UNode, LNode, or BNode respectively. I.e. '[' ID ',' [SULB] ( ',' label )? ']' E.g. [1,S] [3,U,urn:someProperty] [4,L,bar] [9,B] Subject, predicate, and object facets may be represented by arcs with the facet name serving as the arc label and the arc represented by an arrow terminating in the value of the facet. E.g. [1,S] ---- subject -----> [2,U,urn:foo] In cases where the graph is too large to explicitly make the connection, the node ID value can be shown instead. I.e. [1,S] ---- subject -----> 2 An absolute minimal representation can be provided as a list of node definitions such that for SNodes, the values of the subject, predicate, and object facets are listed by node ID in that order, and the arcs are implicit. E.g. [1,S,2,3,4] [2,U,urn:foo] [3,U,urn:someProperty] [4,L,bar] See the extended examples in http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2001Nov/0355.html showing how both data typing as well as general statement qualification are addressed by this proposal. Regards, Patrick -- Patrick Stickler Phone: +358 50 483 9453 Senior Research Scientist Fax: +358 7180 35409 Nokia Research Center Email: patrick.stickler@nokia.com
Received on Thursday, 15 November 2001 04:54:24 UTC