See below for some specific responses. Overall I am still
just not getting the need for this capability. This proposal has been out
there, under various names, for years. OMG, I cannot believe it has been
years L.
The problem, IMHO, is that a solution was discovered before a requirement
or need came to light. Almost by mistake this solution, originally called
concatenated syntax, was discovered while explaining XRIs to others. This
syntax seemed easier to convey the message. Once we had this solution a
requirement was sought out. That is a bit backwards. Usually one
comes up with a requirement before figuring out a solution. As a result
we have been trying to fit a requirement into the solution and none of them
seem to have been articulated very well. I just do not
understand why we need to introduce global subsegements.
From: John Bradley
[mailto:]
Sent: Wednesday, November 26, 2008 1:30 PM
To: Chasen, Les
Cc: ;
Subject: Re: [xdi] on global cross references and the link contract use
case
We need to remember that @cordance is not asked.
If @cordance has an authority service that service is asked
for a XRD.
[Chasen, Les] Right, the authority resolution service for
@cordance is providing the responses.
The Authority service for @cordance can produce a XRD in any
way it sees fit. It may take it from a file or look it up in XDI or some
other database.
[Chasen, Les] Correct
I think the Parenthesis indicate that the thing it
is being handed to resolve is not a normal subsegment it must use some special
processing to produce a XRD for the identifier contained in the
cross reference.
[Chasen, Les] Interesting … Now the parenthetical cross
reference is being referred to as not normal. I am not sure I agree but
if it is special processing seems to make sense. However, special
processing has not been proposed.
Passing *(=Drummond) to a authority server is telling the
authority server to produce a XRD based on the input value of the global
=drummond. It could just go get =Drummond's XRD and return that though
that would brake CID verification.
[Chasen, Les] it could but again special processing has not been
proposed. It would seem that if there really is a significant difference
between GCS subsegments and cross references that there should be. I am
trying to understand this.
I see the (=drummond ) , (+14165551212) or (http://yahoo.com) etc as inputs to some lookup
extension process on the authority server,
and =drummond as a subsegment a request
to retrieve that subsegment from @cordance's authority server.
[Chasen, Les] At this point I just do not see the justification
for this.
Cross references have always been about sending an
opaque string to a authority server to get back a XRD.
[Chasen, Les] an opaque string that represents another
authority.
I don't thingk @cordance+drummond is a
cross reference it is a two subsegment XRI
[Chasen, Les] I do not agree.
=jbradley
On 26-Nov-08, at 10:02 AM, Chasen, Les wrote:
I
need to stick with simple examples and in this case there is only one
authority, @cordance, in question. under the current proposal @cordance is
asked for both =drummond and *(=drummond) and it returns its own xrd if one
exists within @cordance. We have never discussed whether @cordance may go to
the = authorty server for drummond when it is contained within *(=drummond). I
think that maybe interesting behavior.
--------------------------
http://xri.net/=les.chasen
From: John Bradley
To: Chasen, Les
Cc:
;
Sent: Wed Nov 26 12:44:00 2008
Subject: Re: [xdi] on global cross references and the link contract use
case
Les,
I started off with that position. I now think
they are separate queries to the next authority server.
I think that the parenthesized statement may
contain multiple subsegments is the important thing.
Once we have a way to encapsulate multiple subsegments to be
handed to an authority server it is hard to stop someone from
only putting in a single subsegment. in the cross ref.
I think the simple principle is that things
in parenthesis are opaque to the resolver and handed to the next
authority server and things not in parenthesis are resolved left to
right one subsegment at a time.
I also don't think that in ether case @cordance is being
asked anything about the global =drummond if one exists.
In the first case the authority server for @cordance is
being asked for a XRD for the subsegment =drummond the = is treated as part of
the subsegment itself
In the second case the authority server for @cordance
is being asked for a XRD for the subsegment *(=drummond)
I think the latter could be taken that the authority server
may look someplace else to get the XRD for the cross reference.
I think in the former case =drummond is
a subsegment in its authority server.
The question is if it is just a regular subsegment is using
= as a separator going to confuse people.
=drummond is just a regular subsegment with
some inference by Cordance that its =drummond has something to do
with the global =drummond though XRI makes no such claim other things using XRI
like XDI may.
John B.
On 26-Nov-08, at 9:23 AM, Chasen, Les wrote:
Let's
not complicate this with +phone. My question is does @cordance return a
different xrd for =drummond and *(=drummond)? This proposal says yes. I
disagree with this behavior. I think @cordance is being asked for its
representation of =drummond in both cases.
--------------------------
http://xri.net/=les.chasen
From: John Bradley
To: Chasen, Les
Cc:
;
Sent: Wed Nov 26 12:11:59 2008
Subject: Re: [xdi] on global cross references and the link contract use
case
From a XRI resolution perspective I see
a difference in what @cordance's authority server is asked for.
@cordance=drummond , @cordance
is asked for the XRD for =drummond
@cordance=drummond+phone , @cordance is
asked for the XRD for =drummond , @cordance=drummond is
asked for the XRD for +phone
@cordance*(=drummond) , @cordance is
asked for the XRD for *(=drummond)
@cordance*(=drummond+phone) , @cordance is asked for the
XRD for *(=drummond+phone)
Parenthesis in the first segment tell the resolver to
treat the contents as an opaque string and pass it to the next authority
server.
The resolver Parenthesis in the path are
not significant to the resolver they would
be matched during service selection as they are now.
One thing we did start talking about at the F2F is what the
syntax to indicate special processing on a cross reference.
An example:
$XRD*(https://boing.com)*marty
Is $XRD a node that has as its authority service one that
performs XRD resolution on the next subsegment.
So is a $ word in XRI resolution a node that
points to a specialized authority service?
Certainly a resolver has the option
of shortcutting resolution through querying the $XRD
authority server if it understands the $XRD word.
Under Drummond's proposal we do have to have a theory about
what + and $ in the first subsegment resolve to.
John B.
On 26-Nov-08, at 6:51 AM, Chasen, Les wrote:
Hi
Giovanni -
A cross reference is putting the thing cross referenced inside the context of
the xri that contained the cross reference. Terminology in this proposal has
been changing but the thing that hasn't is that in both cases the outer
authority is returning its xrd for the reference. That is, in the example
below, cordance is returning its xrd for =drummond.
@cordance=drummond
@cordance*(=drummond)
So we only support the 'inside' (or better stated container) concept. Now it
may be interesting to consider a resolution process which rather than asking
@cordance for =drummond we ask = for drummond. Today that does not exist.
Have a happy thanksgiving.
Thanks
Les
--------------------------
http://xri.net/=les.chasen
From: Giovanni
Bartolomeo
To: Chasen, Les
Cc: XDI
Sent: Wed Nov 26 09:35:43 2008
Subject: RE: [xdi] on global cross references and the link contract use
case
Hello Les,
First, thank you for having read the contribution! Unfortunately I'm probably
not the best person which can answer your question, as I'm not an expert of
XRI2.0. I limited to develop my contribution in the scope of the current
proposal (
http://wiki.oasis-open.org/xri/XriThree/GcsDelimiter), which, I personally
support for one specific reason: http://lists.oasis-open.org/archives/xri/200811/msg00043.html.
I think Drummond's reply http://lists.oasis-open.org/archives/xdi/200811/msg00031.html
is a good technical explanation of this, expecially the last statement: in
an ordered set, you are not referencing across contexts. The context is the
ordered set itself. For example, in $sig$d, the context for $d is $sig. Which
I understand as follow: put an object inside a context is not exactly the same
as referencing it from that context).
The core of this issue - that's my guess and not a technical explanation
- is probably that XRI2.0 did not consider the need to "put an
instance of an object inside a context", but just to "cross
reference" it. That is instead a fundamental capability for XDI (and for
any human or machine understandable language).
I'll be happy to answer any further questions you might have on the contents of
the contribution itself.
Kind Regards,
Giovanni
At 13.36 25/11/2008, Chasen, Les wrote:
Hi Giovanni. I had a chance to read this. While
I like what you guys
are doing with link contracts I fail to understand why all of these
examples do not work with XRI 2.0 style cross references.
> -----Original Message-----
> From: Giovanni Bartolomeo [
mailto:]
> Sent: Wednesday, November 19, 2008 12:02 PM
> To: XDI
> Subject: [xdi] on global cross references and the link contract use
> case
>
> Hello,
>
> some weeks ago I mentioned that I was playing a bit with the
> semantics of link contracts. Better to say, with the global cross
> references applied to the link contract use case. After the issue of
> XDI RDF model v.11, I put my thoughts in a document which you can find
> below.
> Maybe just semantic nuances, but your comments will be welcome.
>
> Thanks,
> Giovanni
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