RE: [External] [xdi] Multiplicity questions

If you are talking ordinal #s then taking this…

=markus$*(+email)$!1/!/(data:,aaa)

=markus$*(+email)$!2/!/(data:,bbb)

=markus$*(+email)$!3/!/(data:,ccc)

Deleting the second one would give you:

=markus$*(+email)$!1/!/(data:,aaa)

=markus$*(+email)$!2/!/(data:,ccc)

Then adding a new one would give you:

=markus$*(+email)$!1/!/(data:,aaa)

=markus$*(+email)$!2/!/(data:,ccc)

=markus$*(+email)$!3/!/(data:,ddd)

From: xdi@lists.oasis-open.org [mailto:xdi@lists.oasis-open.org] On Behalf Of Markus Sabadello
Sent: Monday, July 02, 2012 1:21 PM
To: OASIS - XDI TC
Subject: [External] [xdi] Multiplicity questions

Example:

=markus$*(+email)$!1/!/(data:,aaa)

=markus$*(+email)$!2/!/(data:,bbb)

=markus$*(+email)$!3/!/(data:,ccc)

I was wondering.. If you first delete let's say the $!2 value, and then add a new value, does the $!2 get recycled?

Or does the counter always keep going up, i.e. $!4 would be issued, even if $!2 is unused?

I think I-Numbers should not be recycled for new values, and new ones should always be issued.

So, I think an extra statement should be introduced to remember the I-Number of the last value:

=markus$*(+email)/$!/$!3 <-- last I-Number

With this statement it gets much easier and more efficient for the server to add a new value of +email.

Or perhaps it would be even better to used GUID-style I-Numbers, then the question of increasing the counter becomes obsolete.

Or perhaps the spec should not specify this, i.e. you could either use sequential I-Numbers, or GUID-style ones, whatever you prefer.

At XDI2 we need this for implementing link contracts and the policy context nodes, which use the multiplicity format.

If this looks right, I'll create a Proposal page.

Markus

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