- From: Andy Seaborne <andy.seaborne@epimorphics.com>
- Date: Wed, 14 Nov 2012 11:32:21 +0000
- To: public-rdf-wg@w3.org
On 14/11/12 11:02, Richard Cyganiak wrote: > Following recent discussions, I've written up a proposal to change the design of blank nodes in RDF by explicitly introducing scoped blank node identifiers into the abstract syntax. > > http://www.w3.org/2011/rdf-wg/wiki/User:Rcygania2/B-Scopes > > Requirements: > > • Consistency with all resolutions the WG has made so far > • No changes to other specs beyond Concepts and Semantics required > • No changes to conforming implementations required > > All further details are in the wiki. > > Comments welcome. > > Best, > Richard > The idea may be OK although adding a new piece of terminology to explain other unclear concepts may not achieve what you hope for. Comments: I have no idea what a "blank node scope" is. [[ There is a widely held misconception in the RDF community that graphs cannot share blank nodes. This stems from the fact in practice they rarely do and almost never need to, ]] Any systems that has the default query graph as the union of named graphs is sharing bnodes across graphs. Such systems are not 'rare'. ... sharing ... [[ but (for the time being) not between graph stores. ]] The skolemization note makes this confusing. While not strictly at odds with it, the appearance of skolemization suggests global bnodes. Alternative for consideration: 1/ Make clear that parsing produces a new blank nodes every time for the same label. 2/ Talk about "fresh blank node" and not the universal not-quite-arbitrary set of blank nodes. 3/ Bnodes are global. Then the "b-scope" and "bNode = (b-scope, label)" is an implementation approach. Andy
Received on Wednesday, 14 November 2012 11:33:14 UTC