Re: again on numbering..

["Markus Sabadello" <markus.sabadello@xdi.org>]

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