- From: Andy Seaborne <andy.seaborne@epimorphics.com>
- Date: Wed, 14 Mar 2012 19:34:41 +0000
- To: public-rdf-dawg@w3.org
[The WG decided not to do path lengths during the F&R phase so my message is a technical discussion, not spec scoping] On 14/03/12 15:06, Olivier Corby wrote: > Andy, > > On 03/14/2012 03:20 PM, Andy Seaborne wrote: >> Where do you stand with regard to leaving open the future possibility >> of length handling in paths? > > I have path length using a path variable and a pathLength() function. It > counts the number of edges in the path: > > ?x exp :: $path ?y > filter(pathLength($path) <= 10) > > I would also support handling length in the path expression. which has the interesting interaction with non-counting; non-counting is a connectivity test. Length brings up the "why are the connected" aspect. As soon as lengths are introduced, I think there will be an expectation that it is the shortest path and maybe longest so is there are aggregation like "minpathlength(all $path) > 2" >> To pick one part of that design space, if a path is suppose to be >> matched with between N and M path steps, does it matter if the path >> also matches with less path steps, or more path steps, and so is >> outside that range as well as being in it? > > I don't understand "does it matter" in the question. > It may happen that there are paths with less steps and path with more, > but if there are steps between N and M it should be ok ? Could well be - I'm not able to scope out the full design space and i was wondering about what use cases there might be. Often shortest paths are the ones of interest. Saying "length between 2 and 4" , or using {2,4}, isn't useful as there is a pseudo-aggregation aspect wanting MIN(length) between 2 and 4. Use case : LinkedIn-ish : if they ask "how is X connected to Y" the shortest path of 2 is useful in determining potential connections but what about backing up that possibility by supporting evidence like the number of length 3 paths? That would be to the exclusion of length 2. filter(pathLength($path) <= 10) is only testing the current candidate. Working over a set of possible paths looks interesting. Andy > > Olivier > > >
Received on Wednesday, 14 March 2012 19:35:16 UTC