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Re: DATATYPES: mental dump.

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Mon, 12 Nov 2001 10:17:20 -0500
To: phayes@ai.uwf.edu
Cc: w3c-rdfcore-wg@w3.org
Message-Id: <20011112101720H.pfps@research.bell-labs.com>
From: Pat Hayes <phayes@ai.uwf.edu>
Subject: DATATYPES: mental dump.
Date: Fri, 9 Nov 2001 12:49:48 -0600

[...]

> The S and CD proposals require that users conform to a given 'idiom', 
> and are often incompatible with current common usage in which 
> literals are used to refer to things other than strings; in contrast, 
> such usage is handled by P and P++.  Also, such idioms may be 
> incompatible with extensions to RDFS, in particular with DAML. (This 
> needs to be checked more carefully.)
> 
> The X proposal is incompatible with all current usage as it requires 
> all literals to be replaced with URVs. However, the translation from 
> current usage into the new form is straightforward and mechanical, 
> and does not require any change to the triples structure (eg does not 
> introduce any new bNodes).

[...]

>                                  X   S   DC  P   P++
> CONS
> requires literals as subjects                   x
> requires change to MT                       x   x
> requires DTs to be 'proper'                 x   x
> requires user conform to idiom (x)  x   x
> (requires literals to be typed) x   x              (pro or con?)
> cannot express 'clashing' types x       x  (x) (x)
> 
> PROS
> fully general                                   x
> conforms to current usage      (x)          x   x
> allows free type merging            x 
> compatible with DAML           (?)          x   ?

[...]


Regardless of the situation with respect to incompatibility with RDF, I
view incompatibility with XML as a fatal problem with both these proposals.
I think that a scheme that is not compatible with

        [possibly some some xml schema stuff that may or may not type the 7 below]
	<foo [possibly some xml schema stuff that may or may not type the 7 below]>
	  <bar [possibly some some xml schema stuff that may or may not
		type the 7 below]>
		7
	  </bar>
        </foo>

is a non-starter.


Peter F. Patel-Schneider
Received on Monday, 12 November 2001 10:18:24 EST

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