- From: Lee Feigenbaum <lee@thefigtrees.net>
- Date: Tue, 07 Jul 2009 09:35:08 -0400
- To: Steve Harris <steve.harris@garlik.com>
- CC: Eric Prud'hommeaux <eric@w3.org>, public-rdf-dawg@w3.org
Steve Harris wrote:
> On 7 Jul 2009, at 01:58, Lee Feigenbaum wrote:
>> Do you mean s/MINUS/UNSAID, I imagine
>>
>>> Result U3 (extrapolated from UNSAID results above):
>>> ?who ?nam _:eve "eve"
>>
>> If I understand UNSAID correctly, you'd do the above MINUS query as:
>>
>> ?who foaf:givenname ?name .
>> UNSAID {
>> ?who foaf:holdsAccount ?act .
>> ?act foaf:accountName ?name .
>> }
>>
>> "People with a certain name for whom it is unsaid that their account
>> has the same name."
>>
>> Is that right or wrong?
>>
>> If it's right, I find (to me) the UNSAID way to be a much more natural
>> way of writing this query - I'm not actually convinced the MINUS
>> version is any clearer than OPTIONAL + !bound :-)
>
> Interesting, I find it easier to get my head around MINUS. For UNSAID
> with OPTIONAL I'd have to map that into a MINUS expression to figure out
> what (if anything) it meant.
I agree that UNSAID + OPTIONAL is a weird combination; I meant that
(again, assuming my understanding is correct) that to accomplish the
goal of the above query with UNSAID -- which doesn't require OPTIONAL --
is much clearer to me than to have to figure out the combination of
MINUS + OPTIONAL that does it correctly.
Lee
>
> - Steve
>
Received on Tuesday, 7 July 2009 13:36:07 UTC