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Re: Can properties have no value?

From: Perry A. Caro <caro@Adobe.COM>
Date: Thu, 30 Sep 1999 14:14:24 -0700
Message-ID: <37F3D2B0.2E6198F2@corp.adobe.com>
To: "Ralph R. Swick" <swick@w3.org>
CC: rdf-dev@mailbase.ac.uk, www-rdf-comments@w3.org
"Ralph R. Swick" wrote:
> I would define it to mean that the value of s:myProperty is an
> anonymous resource about which I know nothing else. 

Thanks for the comments.  I believe I understand the interpretation.  My
only lingering concern is that there appears to be no way to express a
distinguished *literal* which contains no characters, which is sometimes
useful in the real world.  Here, I mean literal in the sense of the data
model (a member of the set of Literals).

I hesitate to call this "anonymous resource about which I know nothing else"
equivalent to a literal with no characters, since it may not always be a
literal. Consider this expression:

<s:myProperty rdf:parseType='Resource'/>

Following the logic of the previous discussion, the value of this property
should be our old friend the anonymous no-statements resource, but the
expression clearly intends for the value to be a resource, not a literal.

To obtain a distinguished no characters literal, I may have to stoop to
something like this:

<s:myProperty rdf:parseType='Literal'><null/></s:myProperty>

Perry
Received on Thursday, 30 September 1999 17:14:29 GMT

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