W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > January to March 2011

Re: Review of revised property path tests

From: Matthew Perry <matthew.perry@oracle.com>
Date: Mon, 28 Feb 2011 05:22:20 -0800 (PST)
Message-ID: <d1969c23-6d31-497b-85b6-d2ff9211d0fd@default>
To: <andy.seaborne@epimorphics.com>
Cc: <public-rdf-dawg@w3.org>
Hi Andy,

Sorry for the confusion. I agree with the revised answer set for the property paths. I had a problem with a definition in the spec that I noticed when reviewing the test cases.

My problem is with this sentence in the doc (from the definition of ZeorOrMorePath and OneOrMorePath in Section 18.4):
"An intermediate node is one which does not form an endpoint of the path match"

Result paths are defined as not repeating intermediate nodes, but I believe that with the semantics we have, the end point of the path should also be categorized as an "intermediate" node because only the start node is allowed to appear again on the path. I was pointing out that, according to this definition, those additional solutions were valid paths because the node that is repeated is an endpoint (the end node). 

In other words, the definition should be "An intermediate node is one that is not the starting point of the path match."

- Matt

----- Original Message -----
From: andy.seaborne@epimorphics.com
To: matthew.perry@oracle.com
Cc: public-rdf-dawg@w3.org
Sent: Monday, February 28, 2011 6:43:47 AM GMT -05:00 US/Canada Eastern
Subject: Re: Review of revised property path tests



On 21/02/11 22:07, Matthew Perry wrote:
> Hi Andy,
>
> I took a look at the revised property path tests.
>
> I have a questions about pp16 and pp25.
>
> The text definition in Section 18.4 allows an endpoint to appear as an
> intermediate node on the path.
>
> In pp16, if we allow this, shouldn't we get these additional solutions:
> {X=:e, Y=:e} for :e - foaf:knows -> :f - foaf:knows -> :e
> {X=:d, Y=:e} for :d - foaf:knows -> :e - foaf:knows -> :f - foaf:knows
> -> :e

I'm a bit lost here - are we talking at cross purposes somehow?


{X=:e, Y=:e} are in the solutions pp16.srx once.  Is that right for 
foaf:knows*? Previously, we did have multiples here but you argued 
against that.

http://lists.w3.org/Archives/Public/public-rdf-dawg/2011JanMar/0158.html
http://lists.w3.org/Archives/Public/public-rdf-dawg/2011JanMar/0169.html

Ditto
{X=:d, Y=:e}

---------------------------------------------------
| X                      | Y                      |
===================================================
| <http://example.org/a> | <http://example.org/a> |
| <http://example.org/a> | <http://example.org/b> |
| <http://example.org/a> | <http://example.org/c> |
| <http://example.org/a> | <http://example.org/c> |
| <http://example.org/b> | <http://example.org/b> |
| <http://example.org/b> | <http://example.org/c> |
| <http://example.org/c> | <http://example.org/c> |
| <http://example.org/d> | <http://example.org/d> |
| <http://example.org/d> | <http://example.org/e> | **
| <http://example.org/d> | <http://example.org/f> |
| <http://example.org/e> | <http://example.org/e> | **
| <http://example.org/e> | <http://example.org/f> |
| <http://example.org/f> | <http://example.org/e> |
| <http://example.org/f> | <http://example.org/f> |
| <http://example.org/h> | <http://example.org/h> |
| "test"                 | "test"                 |
---------------------------------------------------

(this is the srx file, reformatted; not evaluating the query).

> In pp25, we would get this additional solution
> {z=:c} for :a - :p -> :c - :p -> :c

I see the test results for pp25 (<diamond-loop-2.srx) in CVS as:

----------------------
| z                  |
======================
| <http://example/c> |
| <http://example/z> |
| <http://example/b> |
| <http://example/z> |
----------------------

(this is the srx file, reformatted; not evaluating the query).

>
> I don't think we should allow the endpoint to appear as an intermediate
> node on the path, I would rather keep the results as they currently are
> in the tests. From my understanding, the semantics in Section 18.5 do
> not allow an endpoint to appear as an intermediate node.
>
> Thanks,
> Matt
>

	Andy
Received on Monday, 28 February 2011 13:24:46 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:15:45 GMT