- From: Andy Seaborne <andy.seaborne@talis.com>
- Date: Mon, 22 Feb 2010 10:34:05 +0000
- To: Paul Gearon <gearon@ieee.org>
- CC: SPARQL Working Group WG <public-rdf-dawg@w3.org>
On 16/02/2010 4:52 PM, Paul Gearon wrote: > On Tue, Feb 16, 2010 at 10:24 AM, SPARQL Working Group Issue Tracker > <sysbot+tracker@w3.org> wrote: >> >> ISSUE-54: Do we need (descriptions of) property functions in SD? Is this in scope for us? >> >> http://www.w3.org/2009/sparql/track/issues/54 > > I believe that we want this. > > The scope of what property functions are capable of is essentially > unrestricted, so I don't think it's possible to really describe what > these functions do. However, it should be possible to obtain a list of > properties that fall into this category. As a user I would find that > useful in two ways: > > 1. I'd know that using this property in a query, or getting it back in > a result involves entailed data, and not just extensional data. > 2. If I happen to recognize a property from the list, I will know that > a particular feature will be available to me. > > Regards, > Paul Gearon I agree. Property functions are just vocabulary but they also represent a feature that a system provides and an app writer might be aware of. c.f. a custom filter function. Regarding them as a vocaulary of one property seems rather heavy weight. It is hard to define what one is but most of the interesting part is what the specific one does, again, like a custom filter function. We have the opportunity to provide the vocabulary hook to talk about them; it's a feature several systems provide; and the current work on SD gives us a chance to have the same property across descriptions. Andy
Received on Monday, 22 February 2010 10:41:36 UTC