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Re: URI References and context of use

From: Mark Nottingham <mnot@mnot.net>
Date: Thu, 30 Jan 2003 11:30:04 -0800
Message-ID: <001301c2c896$feca5e00$940ba8c0@mnotlaptop>
To: <uri@w3.org>

I agree; context of use isn't a syntactic restriction, so this would suit
better as a schema extension, rather than a type.

(Doing it in Schema is arbitrary; it could also be done in RDF, etc. I
think it's interesting in Schema because it's the way that many formats
are normatively described.)

Cheers,

----- Original Message -----
From: "Martin Duerst" <duerst@w3.org>
To: "Mark Nottingham" <mnot@mnot.net>; <uri@w3.org>
Sent: Thursday, January 30, 2003 6:40 AM
Subject: Re: URI References and context of use


> What is useful is to have different operations on anyURI
> (to use the XML Schema name), so that people wanting to
> do different things with it can do what they want.
> But creating different types would be wrong. Context,
> especially in this case, is more often given by usage
> rather than by the type itself. Stretching things a bit,
> what you are proposing is similar to proposing different
> types for integers that need to be added and those
> that need to be multiplied.
>
> On the contrary, for the integer/string example below,
> and even more so for other cases (anyURI/string definitely
> being one), one can actually argue that creating (completely)
> types is a bad thing, that it would have been easier if e.g.
> anyURI would have been a subtype of string. That would make
> it much easier to use various string operations directly on
> anyURI. Of course, XML Schema doesn't care that much about
> operations, but others (e.g. XML Query) do.
>
> Regards,    Martin.
>
> At 23:32 03/01/25 -0800, Mark Nottingham wrote:
>
> >XML Schema is gathering requirements for 1.1.
> >
> >Question: should a new type be considered, in order to distinguish URIs
> >used as identifiers from those used as locators?
> >
> >In other words - these are very different elements:
> >    <foo type="xsd:integer">0123</foo>
> >    <foo type="xsd:string">0123</foo>
> >and it's clear what's going on. However, schema has no way to
distinguish
> >URIs that are used as identifiers (e.g., in namespaces) from those that
> >are to be used to locate (dereference).
> >
> >It strikes me that this would be useful*, because other specifications
> >could use this mechanism to clearly communicate what the context of the
> >URI is. It would also give guidelines to canonicalization, comparison,
> >etc.
> >
> >Regards,
>
Received on Thursday, 30 January 2003 14:37:58 GMT

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