Re: Proposal: 'tag' URIs

At 05:15 PM 5/7/01 -0400, Michael Mealling wrote:
>On Mon, May 07, 2001 at 05:13:48PM -0400, Simon St.Laurent wrote:
> > At 04:20 PM 5/7/01 -0400, Michael Mealling wrote:
> > >Nope. URNs have the requirement that once you assign a URN to its
> > >Resource you can never reassign that URN to some other Resource.
> > >Sure, you could assign a URN to whatever the http protocol gave you
> > >on port 80 at cnn.com and that would be a useful thing because then
> > >I could rely on the fact that, no matter what CNN did to cnn.com or
> > >whether or not CNN even existed anymore, whenever I used that
> > >URN I knew that someone hadn't changed the meaning out from under me.
> >
> > So does this mean that changing the Resource is effectively creating a new
> > Resource?
>
>Nope. URIs and URNs never define any concepts or operations that have
>to do with the Resource other than the act of binding a URI/URN to one (which
>is how a Resource comes into existence). The statement "changing
>the Resource" has no meaning outside of some specific application that defines
>what "change" means for that application space. Low level caching might
>consider 'change' to be moving it from one IP address to another while
>DAV might define it as a versioning event that doesn't care what IP
>address it is currently at.

I guess my concerns center on:
>someone hadn't changed the meaning out from under me.

I'm concerned about:
a) how you find that meaning
b) what "meaning" means in a resource context
c) how changing a resource avoids changing said meaning



Simon St.Laurent - Associate Editor, O'Reilly & Associates
XML Elements of Style / XML: A Primer, 2nd Ed.
XHTML: Migrating Toward XML
http://www.simonstl.com - XML essays and books

Received on Monday, 7 May 2001 17:24:22 UTC