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Re: Closing ISSUE-13

From: Pat Hayes <phayes@ihmc.us>
Date: Thu, 10 May 2012 16:00:40 -0500
Cc: public-rdf-wg Group WG <public-rdf-wg@w3.org>
Message-Id: <9E8EAD27-F444-44B7-9D21-ABD05D00CE9E@ihmc.us>
To: David Wood <david@3roundstones.com>
Um. Can I raise the issue I was trying (but failing) to clarify through IRC yesterday? It concerns canonical lexical forms. I may be simply not understanding the issue, in which case please someone tell me so. 

Seems to me that if we define a canonical lexical form but also make it optional, then this is worse than just not mentioning it at all. Consider A who publishes some data and B who queries the data. No matter what A does, B does not know that the data is in canonical form, since conformity does not require this. So, B cannot rely on its being canonical, and must proceed cautiously, under the presumption that some data might be uncanonical, and process it (at his expense) to allow for this. And, to repeat, B must do this even if A has, in fact, taken the trouble to canonicalize all the data. Now, A can figure this out himself ahead of time, and so can conclude, correctly, that it is simply not worth the trouble to put his data into canonical form, since users of it will never know it is, and will have to treat it as potentially uncanonical anyway, so why bother? So, it seems to me, an optional caonicalization is simply pointless. It serves only to confuse things. 

One way out of this problem is to *require* canonical lexical forms, but this puts all the onus onto the publisher. Another possible way to proceed is to have two closely related datatypes, one of them just like the other but with its lexical form compulsory. So we might have rdf:CXMLLiteral whose specification is exactly like rdf:XMLLiteral except that the lexical form is *required* to be http://www.w3.org/TR/xml-exc-c14n/ . The point being that this enables A to, in effect, publish the fact that his data is nice and tidy, so that B can rely on it. AFAIKS, this idea is essentially zero cost to implementors and users, and has a very small cost to the WG.  

But as I say, I might be missing the whole point. 

Pat


On May 9, 2012, at 11:45 AM, David Wood wrote:

> Hi all,
> 
> Today, we resolved [1]:
> [[
> RESOLVED: in RDF 1.1: [a] XMLLiterals are optional; [b] lexical space consists of well-formed XML fragments; [c] the canonical lexical form is http://www.w3.org/TR/xml-exc-c14n/, as defined in RDF 2004; [d] the value space consists of (normalized) DOM trees.
> ]]
> 
> Richard's proposal [2], that evolved into this resolution, was meant to close ISSUE-13 [3].  So, I have changed the status of ISSUE-13 to "pending approval" and suggest that the implementation of this resolution be considered editorial in nature.
> 
> Any objections?
> 
> Regards,
> Dave
> 
> [1] http://www.w3.org/2011/rdf-wg/meeting/2012-05-09#resolution_1
> [2] http://lists.w3.org/Archives/Public/public-rdf-wg/2012May/0006.html
> [3] https://www.w3.org/2011/rdf-wg/track/issues/13
> 
> 
> 
> 

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Received on Thursday, 10 May 2012 21:01:13 GMT

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