W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > November 2001

Re: datatypes and MT

From: Pat Hayes <phayes@ai.uwf.edu>
Date: Thu, 8 Nov 2001 19:26:08 -0600
Message-Id: <p0510101db810dea82089@[65.212.118.147]>
To: Dan Connolly <connolly@w3.org>
Cc: w3c-rdfcore-wg@w3.org
>Pat Hayes wrote:
>[...]
>>  >>  >If we want to say "my shoe size is some
>>  >>  >integer whose decimal representation is '10'",
>>  >>
>>  >>  But I don't want to say that. I want to say that my shoe size is 10.
>>  >
>>  >Yes, but we're not here to design a syntax; we're here to
>>  >clarify the existing one. And the existing one doesn't have
>>  >that expressive power, I don't believe.
>>
>>  Is
>>
>>  Pat shoeSize "10" .
>>
>>  illegal RDF, in the current syntax? (Assuming that 'Pat' and
>>  'shoeSize' were urirefs, of course.)? Because I read that as saying
>>  that my shoe size is ten.
>
>That is legal RDF/xml syntax (or rather: it corresponds
>to RDF/xml syntax in a way that the WG has agreed on),
>but the way you read it is exactly
>the issue we're debating. I read it as saying that something
>denoted by the uriref Pat is related by a relation
>denoted by the uriref shoeSize to a two character string
>'1' '0'. i.e. it corresponds to
>	(shoeSize Pat "10")
>in KIF.
>
>The shoeSize relation might be defined in such a way
>that allows you to conlude that your shoesize is ten.
>
>[...]
>>  >The usual interpretation of "10" -- e.g. in KIF -- is
>>  >a string of two characters, no? I don't see what's unusal
>>  >about what I'm suggesting.
>>
>>  OK, Ive been assuming that the quote marks around literal labels are
>>  only a syntactic device for marking them as literals, not intended to
>>  be interpreted as actual quotation marks. They are an inheritance
>>  from XML, right?
>
>Not in any particular way; n-triples syntax is independent
>from XML.
>
>>  And XML is completely sloppy about use and mention,
>>  and uses quotation syntax to mean all kinds of things.  If we are
>>  obliged to interpret those as genuine quote marks,
>
>we are not obliged
>
>>  then I give up;
>>  there is nothing to debate: all literals are character strings, end
>>  of story. But then if I write
>>
>>  Pat shoeSize "10"
>>
>>  then I am saying that my shoe size is a character string, right?
>
>That's my suggestion.

But like I said in an earlier thread, that seems *obviously wrong*. 
And as you said, it *is* obviously wrong, but all these silly people 
insist on writing these obviously wrong things. Doesn't that suggest 
that they are not writing obviously wrong things, in fact, but rather 
interpreting those double quotes differently?

>  >  From here on I will omit the double quotes to avoid confusion.
>
>er... huh? You'll have to tell me how your new syntax
>relates to RDF/xml syntax, then.

I just meant to avoid the implication that they were to be 
interpreted as strings, since that interpretation begs the question. 
If we can agree that XML syntax in general should not be interpreted 
using logical canons of notational rigor, then we can leave the quote 
marks there and not call them quotes.

>[...]
>
>>  >I don't see the simplicity anywhere.
>>
>>  Well, I do. The motivating example for me was the use of range
>>  information to fix a datatype, as in
>>
>>  aaa shoeSize 10 .
>>  shoeSize rdfs:Range xsd:integer .
>>
>>  which seems to me to be eminently simple.
>
>That would be nifty if RDF/xml had such a syntax.
>I believe/suggest that it does not.
>
>So that example is irrelevant, from my perspective.

OK, OK, put the quote marks back in; but don't insist on thinking of 
them as quotes.

>
>[...]
>>  >Yes, as I said, the mapping is unambiguous. This doesn't seem
>>  >all that awkward to me.
>>
>>  But if leading zeros are optional, the lexical-to-value mapping is
>>  not invertible, so what is its inverse supposed to be?
>
>(a) as a relation, it *is* invertible; its inverse is
>not a function, but it's a well-defined relation.

Ah. So this would be OK, would it?

aa eg:prop _:x .
_:x xsd:integer "10"
_:x xsd:integer "0010"

That does make sense, I agree.

Pat
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Received on Thursday, 8 November 2001 20:26:01 EST

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