W3C home > Mailing lists > Public > xml-uri@w3.org > May 2000

Re: Are *relative* URIs as namespace nemes considered harmful?

From: Tim Berners-Lee <timbl@w3.org>
Date: Thu, 25 May 2000 05:43:48 -0400
Message-ID: <000201bfc6a1$ae3a64c0$a80a1712@ridge.w3.org>
To: "James Clark" <jjc@JCLARK.COM>, "David Carlisle" <davidc@nag.co.uk>
Cc: <xml-uri@w3.org>
Bravo!  James put it very well.

Tim BL

(Yes, I found an unread section of this list so my order of reading has been
discontinuous)


-----Original Message-----
From: James Clark <jjc@JCLARK.COM>
To: David Carlisle <davidc@nag.co.uk>
Cc: timbl@w3.org <timbl@w3.org>; xml-uri@w3.org <xml-uri@w3.org>
Date: Tuesday, May 23, 2000 8:50 AM
Subject: Re: Are *relative* URIs as namespace nemes considered harmful?


>David Carlisle wrote:
>>
>> > That's not the problematic case.  The problematic case is when you have
>> > two URI references that are identical when compared as strings but
refer
>> > to different resources (because they have different base URIs).
>>
>> I don't understand why this is a problem.
>> If I took the above quote out of this namespace thread and stuck it in a
>> thread about the merits of using the HTML <a> element. Then in what way
>> would it be diferent. The href="foo.html" is the same string but refers
>> to different resources (because they have different base URIs).
>
>If I have a low level layer that doesn't make a distinction between two
>namespace names even though the namespace names identify different
>resources, it will be difficult to build on top of this a higher level
>layer that uses the namespace name directly to access the resource,
>because it will be ambiguous what the resource associated with a
>namespace name is.
>
>The other way around isn't a problem.  If a low-level layer says
>"http://www.w3.org/" and "http://WWW.W3.ORG/" are distinct, then there's
>still a well-defined mapping from namespace names to resources that can
>be used by higher level layers.
>
>In general, a higher level layer can easily identify things that lower
>level layers distinguish, but it's awkward for a higher level layer to
>distinguish things that a lower level layer identifies.
>
>James
>
Received on Thursday, 25 May 2000 19:32:23 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 20:32:42 UTC