Re: [xdi] Re: again on numbering..

[Peter Davis <peter.davis@neustar.biz>]

A general observation wrt the X3 graphs being proposed here:

I am seeing an increase in the discussions were predicate values are  
being explicitly declared in the XRI productions.  I think this  
approach can be wrought with peril...

My concern revolves around the exposure of communication endpoints in  
identifiers.  This was a property that made XRI's to me very  
compelling.  I can share some concrete identifier (and a path into,  
for example, to a predicate eg: xri://=peterd/+email) without  
exposing the email literal.  rather, a service endpoint which might  
handle XDI (for example) requests can apply some set of security  
policies before responding with some (if any) values. Out of  
curiosity, why would i want to express the value of a predicate in  
the identifier itself (rather than a pointer to it's value)?

Here i am seeing attributes of identity being regularly used in the  
identifiers, and thus the privacy properties of the communication  
endpoints are lost.

I realize that i have not been active on this list for some time, and  
so i may be taking the use of the identifiers being expressed here  
out of context, but if my interpretation of this discussion is  
correct, i see what i think is a misuse of XRI as an address into my  
attribute graph.

my .02

=peterd

On Jan 29, 2008, at 12:41 PM, Markus Sabadello wrote:

> Heya Giovanni,
>
> I think the idea of having a way to express ordered collections in  
> XDI would be very useful...
>
> We came across a similar problem a few days ago.. How do we express  
> multiple values for a predicate? For example, =markus could have  
> multiple e-mail addresses. We came up with the following idea:
>
> =markus/+email!1/"markus.sabadello@gmail.com"
> =markus/+email!2/"markus.sabadello@xdi.org"
>
> But your pattern would work too:
>
> =markus+email/$num$1/"markus.sabadello@gmail.com"
> =markus+email/$num$2/"markus.sabadello@xdi.org"
>
> A third idea Drummond had was to use inner graphs, like this:
>
> =markus
>     +email
>         /
>             $
>                 $1
>                     "markus.sabadello@gmail.com"
>                 $2
>                     "markus.sabadello@xdi.org"
>
> I like all three methods.. But we should probably decide on one of  
> them.. Or just experiment for a while and see what works best...
>
> Markus
>
> On 1/29/08, Giovanni Bartolomeo <giovanni.bartolomeo@uniroma2.it>  
> wrote: Hello,
>
> some new inputs about this issue:
>
> >* Markus asked if $num is always used in conjuntion with $has  
> predicate, or
> >if there would be other uses? Giovanni said it would also be useful
> >standalone.
>
> I think that $num could be useful also in accessing arrays, vectors
> and similar structures what we could call "ordered collections".
>
> Let's consider again this use case:
>
> =football.team/$has$num$11/+player
> @as.roma.calcio/$is$a/+football.team
>
> we could index each player using $num${x} as follow:
>
> @as.roma.calcio+player/$num$0/=curci
> ...
> @as.roma.calcio+player/$num$7/=derossi
> ...
> @as.roma.calcio+player/$num$10/=totti
>
> etc.
>
> Do you think this capability could be of help for XDI?
>
> BTW maybe we can avoid the prefix $num and leave only ${num}, e.g.
> $0, $5, $7 are valid XRIs which represent the number 0, 5, 7.
>
> What do you think?
>
> Bests,
> Giovanni
>
>
>
>