- From: Kendall Clark <kendall@monkeyfist.com>
- Date: Thu, 30 Sep 2004 09:06:24 -0400
- To: DAWG public list <public-rdf-dawg@w3.org>
On Thu, Sep 30, 2004 at 02:01:50PM +0100, Steve Harris wrote: > > In order to close the disjunction issue, I propose that we drop any > requirement for graph disjunction in this version of the query language. I don't presently support such a proposal, but I might be persuaded to... > OR is the only infix operator we have prposed so far, so it complicates > the syntax from the point of view of learning it, and makes the precidence > rules more complex and requires logical ()'s to scope expressions. I see these differently: (1) the learning cost is negligible, IMO; (2) the implementation burdens are mostly one-time and only for a few people. And I'm not convince they're that onerous anyway. > Disjuntion provides a lot of the same capability as optional matches, but > as a developer I've only seen feature reqests expressed in terms of > optional match, no disjunction. Many disjunctive queries can be expressed > in terms of optionals and value disjunctions, but I have not attempted to > show wether all can be or not. What would seal the deal for me is a more detailed argument that optionals and value disjunctions really do handle all (or nearly all) disjunction uses. That is, I want to know which disjunction cases *aren't* covered before I support removing it from the language. I want to know what I'm giving up, in other words, before I give it up. > Getting good coverage for test cases will be hard. Esspecially in > combination with optional it allows you to write some really complex > expressions. Testing all combinations will be difficult. Again, that's a fair point, but doesn't persuade me by itself. Best, Kendall
Received on Thursday, 30 September 2004 13:08:57 UTC