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/+email!2/""
But your pattern would work too:
=markus+email/$num$1/""
=markus+email/$num$2/""
A third idea Drummond had was to use inner graphs, like this:
=markus
+email
/
$
$1
""
$2
""
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 <> 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
