W3C home > Mailing lists > Public > public-rdf-shapes@w3.org > August 2014

Re: Graph normalization/canonicalization (was: regression testing [was Re: summarizing proposed changes to charter])

From: Manu Sporny <msporny@digitalbazaar.com>
Date: Fri, 15 Aug 2014 13:42:40 -0400
Message-ID: <53EE4690.3060407@digitalbazaar.com>
To: Markus Lanthaler <markus.lanthaler@gmx.net>
CC: public-rdf-shapes@w3.org, 'Dave Longley' <dlongley@digitalbazaar.com>
On 08/15/2014 12:13 PM, Markus Lanthaler wrote:
> On 15 Aug 2014 at 04:15, Holger Knublauch wrote:
>> On the specific topic, we have had requests for reliably sorted 
>> Turtle files for years, especially so that people can compare 
>> versions of the same file with concurrent versioning systems.
> 
> The JSON-LD CG worked on graph normalization [1] but there wasn't 
> really enough interest (apart from Digital Bazaar) to continue the 
> work on it.

So the "not enough interest" bit did apply to the JSON-LD group in
2012-2013. The upcoming Web Payments and Credentials work depends
heavily on there being a standard way to normalize RDF graph data.

There is a /huge/ amount of interest in getting this done, it's just
that the number of people that are technically capable of understanding
and working on the problem are few and overworked.

Just to clarify, Digital Bazaar is claiming that we've solved the
problem and that there is an algorithm that needs to be reviewed by the
broader community. The current RDF Graph Normalization spec is horribly
out of date, but the implementations are not. We do intend to pick the
work back up soon because the Web Payments CG and Credentials CG work
can't go to REC w/o the RDF Graph Normalization spec going to REC as
well. Getting JSON-LD done diverted us temporarily.

There are multiple implementations of this RDF Graph Normalization
algorithm, and the graph normalization algorithm hasn't changed since
2012. We've hit the point where we're not seeing any more bugs in the
algorithm.

https://github.com/digitalbazaar/jsonld.js/blob/master/js/jsonld.js#L2680

https://github.com/digitalbazaar/pyld/blob/master/lib/pyld/jsonld.py#L2139

https://github.com/digitalbazaar/php-json-ld/blob/master/jsonld.php#L2656

If there were a way to advance this specification to REC, Digital Bazaar
would jump at the opportunity and do the heavy lifting (as long as we
could find the funding and clear people to work on it - which we would
make a priority). It makes it possible to implement the Trust layer of
the semantic web layercake. That we don't have such a facility yet (the
ability to do comparisons between graph data) is holding Linked Data back.

I'm going to be hitting this point hard at this year's SemTech 2014
presentation:

https://web-payments.org/slides/2014/semtech/#slide12

-- manu

-- 
Manu Sporny (skype: msporny, twitter: manusporny, G+: +Manu Sporny)
Founder/CEO - Digital Bazaar, Inc.
blog: High-Stakes Credentials and Web Login
http://manu.sporny.org/2014/identity-credentials/
Received on Friday, 15 August 2014 17:43:04 UTC

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