Re: Intersection use case

David Hull wrote:
> I know from one source that a given server understands WS-Addressing and 
> can handle non-anonymous response endpoints.  Furthermore, this source 
> tells us that said endpoints must have either HTTP or Jabber 
> destinations.  (for concreteness, you might think of this as a default 
> behavior for a site)
> 
>  From another source, we learn that this same server's non-anonymous 
> response endpoints must have either Jabber or Mailto destinations. (and 
> this might be further description of the particular server)
> 
> Combining the information from these sources, we conclude that said 
> non-anonymous endpoints must have Mailto destinations.
> 

I assume you mean 'must have Jabber destinations.'

> How do we express all this in WSP?  In particular, can we use policy 
> intersection to combine the information from the two sources and get the 
> expected result.
> 

IIUC, that is exactly what policy intersection is meant to do.
Instead of getting information about the same server from two different 
sources, the more common example is intersection of policies at the 
service-side with that of the client-side.

> Variant:  Instead of "must have" the sources tell us that the EPRs "may 
> have" the given kind of destination.  The combined information is thus 
> that the destinations may be HTTP, Jabber /or/ mailto.
> 
> Further variants: It seems reasonable for sources of information to be 
> able to say things like "must not have ...", or for one source to say 
> "must have HTTP or Jabber" and another to say "must not have jabber".

Policy does not have a not operation, so I don't how this use case could 
be satisfied by the framework. Policy experts?

-Anish
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Received on Tuesday, 1 May 2007 05:20:38 UTC