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Re: Input sought on datatyping tradeoff

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Mon, 15 Jul 2002 19:54:06 +0100
Message-Id: <5.1.0.14.0.20020715194955.02a00e80@0-imap-1.hpl.hp.com>
To: Drew McDermott <drew.mcdermott@yale.edu>, www-rdf-logic@w3.org

At 11:53 13/07/2002 -0400, Drew McDermott wrote:


>    [me]
>    >We've been assuming that for
>    >every property (here, dc:property in particular) there is a parser
>    >that unambiguously specifies how to interpret the strings that occur
>    >as its values, even if we don't know what that parser is.
>
>    [Brian McBride]
>    I wasn't aware I was making that assumption, but maybe I was.  I think I
>    was assuming that the model theory will say there must be something in 
> the
>    domain of discourse the _:l binds to.
>
>I think the assumption is inevitable if Idiom 2 is going to stick
>around, which it apparently is.

I wouldn't make that assumption yet.  Whilst we've been working on 
datatypes for a while, we haven't even got to first wd yet.


>  The alternative is to say that RDF
>triples *always* have an uninterpreted string as their third element,

That would be such a strange thing to do, I wonder if there is some 
fundamental miscommunication between us.

>which means that Idiom 1 is no longer correct.  Since Idiom 1 is
>obviously better than Idiom 2, that would be a big mistake.
>
>By the way, let me clarify what I am saying so that it doesn't come
>off as implying that XML must be junked, which I acknowledge is out of
>the question.  I am perfectly content to allow notations such as
>
>    <rdf:Description...>
>       <abc:ageInYears>10</abc:ageInYears>
>    </rdf:Description>
>
>just as now.  It's just that 10 would be parsed as a decimal integer.
>(Binary integers would have some other notation, such as "10b2" .)  If
>you wanted a string, you would put quotes in:
>
>    <rdf:Description...>
>       <abc:title>"10"</abc:title>
>    </rdf:Description>

In some ways, I think what you are saying is similar to Peter, that we need 
a syntactic way to distinguish these different things.


>Alas, we have to confront the fact that properties can be moved into the
>attribute list, when quotes reappear.  We could use single quotes for
>that purpose:
>
>       <abc:film .... abc:ageInYears='10' abc:title='"10"' />
>
>For N3, the issue doesn't come up, so we always dispense with
>superfluous quotes:
>
>      <abc:film> <abc:ageInYears> 10 ; <abc:title> "10" .
>
>We still have to have conventions to handle strings containing awkward
>characters such as angle brackets and quotes.

One way to do this might be to use the xml schema syntax:

   <abc:age xsi:type="xsd:decimal">10</abc:age>

Brian
Received on Monday, 15 July 2002 14:55:09 GMT

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