W3C home > Mailing lists > Public > public-rdfa-wg@w3.org > August 2010

ISSUE-29: Re: When is equal and when is it nonequal (eg, the IRI interface)

From: Manu Sporny <msporny@digitalbazaar.com>
Date: Sun, 01 Aug 2010 21:28:29 -0400
Message-ID: <4C561F3D.2010604@digitalbazaar.com>
To: Toby Inkster <tai@g5n.co.uk>
CC: Ivan Herman <ivan@w3.org>, W3C RDFa WG <public-rdfa-wg@w3.org>
On 06/09/2010 04:53 PM, Toby Inkster wrote:
> On Wed, 9 Jun 2010 17:44:41 +0200
> Ivan Herman <ivan@w3.org> wrote:
>> The problem is as follows. In a package like RDFLib, the equality is
>> fairly simple, it is based on the equality of the URIs (let us put,
>> for a moment, the issue of IRI vs URI and its encoding aside).
>> However, our version of the IRI has two attributes: the 'value' and
>> the 'origin'. Ie, to IRI instances that have the same value but
>> different origins are different.
> 'origin' as specified needs fixing. Rather than:
> 	triple.subject.origin
> We should have:
> 	triple.subjectOrigin
> That way testing for equivalence between IRIs, Blank nodes and Literals
> becomes obvious.
> <> rdfs:seeAlso
> <http://lists.w3.org/Archives/Public/public-rdfa-wg/2010Apr/0161.html>.

Unfortunately, I don't think the answer to this one is as simple as
that, Toby. It assumes that we're operating in a DOM environment, which
we can't depend on for the RDFa API.

I've updated the RDFa API spec to move "origin" into a
developer-modifiable attribute called info. We also had to rename
"origin" to "source" due to Thomas' input on ISSUE-29. So, the way you
access the property at the moment is:


That's not great... definitely would like to hear some suggestions on
how we could make this easier on developers. The "info" mechanism is
meant to be a free-form developer-modifiable mechanism for storing
additional information along with subjects, predicates and objects. Mark
had asked for something like this as had Nathan and a few others.

However, I think your and Ivan's issue has to do with equivalence
testing, which may be a completely separate discussion (and may need an
ISSUE of its own).

AFAIK, there are two types of equivalence testing that we could do with
the RDFa API. The first performs equivalence testing for just the triple
information, that is, purely on the subject/predicate/object data
(including datatype and lang information).

The second type performs equivalence testing on the information above,
in addition to the source Element information.

Perhaps we should specify a section in the RDFa API that clarifies the
different types of equivalence testing one can do via the RDFa API. I'm
a bit hesitant to specify the "correct" way to do equivalence testing in
the RDFa API spec as there are many ways to do it.

-- manu

Manu Sporny (skype: msporny, twitter: manusporny)
President/CEO - Digital Bazaar, Inc.
blog: WebApp Security - A jQuery Javascript-native SSL/TLS library
Received on Monday, 2 August 2010 01:28:58 UTC

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