RE: URIS for Literals (was: Re: referendum on httpRange-14 (was RE: "information resource"))

Regarding a proposed URI such as:

        http://www.w3.org/2004/SchemaSimpleTypes/Integer/12

Patrick Stickler writes:

> Why would they be preferable to any other form of
> URI? Despite the fact that humans might recognize
> that they seem to pertain to literal values, the
> principle of URI opacity would preclude any agent
> (or human) from concluding that they actually do
> identify literal values, 

I think you miss the point.  The idea is that there is >some< URI for the 
member of the type xsd:Integer corresponding to the number 12.  That's 
clearly, IMO, a different resource than the string of characters "1","2". 
I believe Chris agrees that his proposed URI is most appropriate to the 
latter.

The http URI shown is just an example of one way of naming the resource.

> since the http: URI scheme says nothing 
> about such interpretations.

I disagree.  The http URI scheme spec very clearly says, as far as I know, 
that the URI quoted above is under the control of the w3c, insofar as w3c 
is the domain name holder for www.w3.org.   So, if the w3c says that the 
URI above stands for the member of the xsd:Integer type in question, then 
it does.  The conclusion is not licensed by micro-parsing the URI unless 
the W3C tells you to.  It's licensed by the URI telling you that this is 
their intended use of the URI.

Maybe or maybe not the w3c would want to host servers that would return 
representations of that resource, such as a nice looking PNG file showing 
a picture of the digits 1 and 2, or a RDDL document giving information 
about the resource, an HTTP page titled "Description page for xsd:Integer 
12", or a document with RDF statements, etc.  If such representations were 
provided, then one of the ways you could make the association between the 
URI and the resource would be by inferrence from the retrieved 
representations.

FWIW, the http scheme spec, drawing on RFC 2396,  futher says that the 
above URI is some sort of hierarchical name for a resouce.  That seems to 
suggest that having:

        http://www.w3.org/2004/SchemaSimpleTypes/Integer/12
        http://www.w3.org/2004/SchemaSimpleTypes/Integer/13

and

        http://www.w3.org/2004/SchemaSimpleTypes/boolean/true

as URI's is at least a plausible use of URI space. 

BTW:  I am not trying to signal a preference on the hash/slash question. 
Maybe


        http://www.w3.org/2004/SchemaSimpleTypes/Integer#12

is better.

The only point of the note was to suggest the possibility of well known 
stable URIs for schema simple type members, and maybe for values from 
other type systems as well.


--------------------------------------
Noah Mendelsohn 
IBM Corporation
One Rogers Street
Cambridge, MA 02142
1-617-693-4036
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Received on Monday, 1 November 2004 19:41:38 UTC