- From: Jan Grant <Jan.Grant@bristol.ac.uk>
- Date: Tue, 10 Apr 2001 11:41:02 +0100 (BST)
- To: Danny Ayers <danny@panlanka.net>
- cc: Sandro Hawke <sandro@w3.org>, www-rdf-interest <www-rdf-interest@w3.org>
On Tue, 10 Apr 2001, Danny Ayers wrote: > > <- Issue 1: RDF M&S Does Not Provide Sets > <- > <- The argument against them I've heard is "we don't have an enforcement > <- mechanism" (for duplicates, so use bags) or "we have to provide them > <- in some order" (so use lists). > <- > <- I think those arguments against defining a vocabulary for > <- communicating information about set membership are, to put it mildly, > <- weak. > <- > <- On the first point, you don't need to provide an enforcement > <- mechanism. If someone says "X contains 3" and then "X contains 3" > <- again, well, you know "X contains 3". No problem. > > IANAL, but don't we still need to be able to tell the difference between > e.g. {1, 2, 3, 4} and {1, 3, 2, 3, 3, 3, 4, 3}? What difference? They're both representations of the same set. > There is definitely elegance to LISP-style lists, though personally I can't > judge how appropriate they would be in this context - the RDF model is > pretty much object-orientated (maybe transformed a little) - how well does > the mix of lists & objects work in e.g. CLOS? I was initially taken with this construct (I think pretty much everybody has invented this as a notion as some point) but I'm less inclined to like it now. Why? Weeeell, why not use something slicker, like balanced trees? Or any other data structure of your choice? I prefer the abstraction of just using numbered members. An RDF implementation is free to use whatever datastructure it pleases behind the scenes*; given a little API support, there need be no O(n) cost for fetching the _n_th sequence member, etc. jan * http://tribble.ilrt.bris.ac.uk/~cmjg/rdf/java/RDF.tar.gz for a snapshot of an (in-progress) example of this, amongst other things. -- jan grant, ILRT, University of Bristol. http://www.ilrt.bris.ac.uk/ Tel +44(0)117 9287163 Fax +44 (0)117 9287112 RFC822 jan.grant@bris.ac.uk User interface? I hardly know 'er!
Received on Tuesday, 10 April 2001 06:43:03 UTC