- From: Tim Berners-Lee <timbl@w3.org>
- Date: Thu, 25 May 2000 05:43:48 -0400
- 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