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Re: Alternate proposal for new terms for g-snap, g-box and g-text

From: Sandro Hawke <sandro@w3.org>
Date: Thu, 21 Jul 2011 01:33:54 -0400
To: Ian Davis <ian.davis@talis.com>
Cc: RDF WG <public-rdf-wg@w3.org>
Message-ID: <1311226434.2599.154.camel@waldron>
On Thu, 2011-07-21 at 01:08 +0100, Ian Davis wrote:
> 
> I think it would be useful to talk about some of the characteristics
> of these concepts e.g. equivalence
> 
> Two TripleSets are equivalent if they conform to the bijection defined
> at
> http://www.w3.org/TR/2004/REC-rdf-concepts-20040210/#section-graph-equality
> (i.e. they differ only in the identity of their blank nodes).
> 
> Two TripleSet Containers are equivalent if their contained TripleSets
> are equivalent
> 
> Two TripleSet Serializations are equivalent if they parse to
> equivalent TripleSets 

I'm not sure what this does for us; what I think is important here is
identity/equality, not equivalence.

1.   Two g-snaps are identical (ie the same g-snap) if they contain
exactly the same triples.   It hasn't occurred to me in the past, when
I've said this, that b-nodes can in some theoretical sense be
distinguished.   Is the g-snap serialized by "<a> <b> _:c" the same as
the one serialized by "<a> <b> _:d"?   I guess turtle doesn't give us
enough information to know.  Is it the same as the one serialized by the
same bytes as the first time, "<a> <b> _:c", on a second reading?
Again, I guess we can't tell. Those two g-texts, read a total of three
times, sure seem to me to be serializing the same one g-snap -- but
maybe it's three different g-snaps which are all graph-equivalent.

2.   Two g-boxes are identical (ie the same g-box) if they must by
definition contain exactly the same g-snap as each other, at all points
in time.

3.   Two g-texts in a given syntax are identical (ie the same g-text) if
they are character-by-character or byte-by-byte (depending on whether
it's a character or byte syntax) the same.  That is, it's just string
compare.

    -- Sandro
Received on Thursday, 21 July 2011 05:34:03 GMT

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