W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > April to June 2012

Re: Problem with test pp28

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Tue, 12 Jun 2012 10:13:11 +0100
Message-ID: <4FD70827.6030604@epimorphics.com>
To: public-rdf-dawg@w3.org

On 11/06/12 21:41, Matthew Perry wrote:
> Thanks Greg. That makes sense, and I see that in the definition now, but
> some of the text in the doc may be a bit misleading:
> "There is also a "zero or one" connectivity property path operator, ?."
> ... "Such connectivity matching does not introduce duplicates (it does
> not incorporate any count of the number of ways the connection can be
> made) even if the repeated path itself would otherwise result in
> duplicates."
> I know we already approved all of this stuff, so I'm not suggesting that
> we change anything at this point.

The quoted text is right, and the definitions evaluates to a set (and so 
the test is wrong ... as was some of my code).


> Cheers,
> Matt
> On 6/11/2012 3:44 PM, Gregory Williams wrote:
>> On Jun 11, 2012, at 3:32 PM, Matthew Perry wrote:
>>> I think property path test pp28 may have an error. If '?' is a
>>> connectivity operator, then how is :z in the result twice?
>> '?' isn't just a connectivity operator -- it just adds results (the
>> zero-length path results) to the path it is applied to (in this case,
>> ':p/:p'). And since :p/:p just expands to a BGP, you get the doubled
>> results since :z can be reached twice from :a (through either :b or :c).
>> .greg
Received on Tuesday, 12 June 2012 09:34:10 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 7 January 2015 15:01:06 UTC