[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: RE: [xri] GCS Characters
|
This does not help me understand why there needs to be two
mechanisms. I think introducing a nuanced semantic difference such as this
leads to confusion. If there truly is a need for the semantics being
introduced here they can probably be expressed more explicitly at the meta data
layer. However, I will keep an open mind and read the “Semantic web for
the working ontologist” … maybe I can find reasons that escape me so far. From: Drummond Reed
[mailto:drummond.reed@cordance.net] The GCS Delimiter proposal (http://wiki.oasis-open.org/xri/XriThree/GcsDelimiter)
goes into great depth about why XDI needs the level of precision provided by
both GCS delimiters and cross-references. Cross-reference syntax (syntactically
encapsulating identifiers by enclosing them in parentheses) is essential for
being able to put any identifier (a URI or an XRI) in another context. For
example, in my last message I showed how it could be used to indicate –
anywhere within an XRI – that a URI represented a resource in either a personal
or an organizational context:
...=(http://example.com/data/uri)...
...@(http://example.com/data/uri)... This isn’t something we want to give up. At the same time, the extreme semantic precision of XDI RDF (which
is really to say the extreme semantic precision of any RDF vocabulary compared
to natural language vocabularies like English) also needs to be able to express
that a resource in one XDI global context can be referred to directly within
another XDI global context. That means the ability to express any combination
of the following XRIs:
=example
@example
+example
$example E.g.:
@example+example
+example$example
@example+example$example
@example=example
=example@example In XDI RDF, all of these represent very precise RDF statements
about the relationship between two resources that can be independently
identified in a global context. Adding parens, stars, or bangs would change
those XDI RDF statements as explained at http://wiki.oasis-open.org/xri/XriThree/GcsDelimiter.
In conclusion, Les, I don’t think there is any satisfactory answer
to your question when you are looking at XRI syntax from a natural language
standpoint. To a human being, =drummond@microsoft.com and
=drummond*(@microsoft.com) don’t look that different. However to a machine,
they are different identifiers, and when you need the precision of a semantic
language like XDI RDF, this difference becomes critically important. On that score, for TC members who are not intimately familiar with
RDF, I did a blog post about a new book called Semantic Web for the Working
Ontologist: http://www.equalsdrummond.name/?p=164 I recommend it very highly because it does such a good job at
explaining to reasonably web-savvy technologists how RDF really works and what
kinds of problems in machine-understandable semantics it can solve. =Drummond From: Chasen, Les
[mailto:les.chasen@neustar.biz] I
continue to struggle with why we need two ways to put a global xri in the
context of another xri. =drummond@microsoft.com and =drummond*(@microsoft.com)
seem to do the same thing. If the later is less than desirable let's drop ()'s
in xri. From: Drummond Reed First, just to address some clarification questions in this thread,
the proposal under discussion, called GCS Delimiter, is posted at: http://wiki.oasis-open.org/xri/XriThree/GcsDelimiter The accompanying ABNF that implements this proposal is at: http://wiki.oasis-open.org/xri/XriThree/SyntaxAbnf
As described there in more detail, the proposal is that in XRI 3.0,
all GCS characters (=, @, +, $) are treated in XRI syntax as delimiters just
like * and ! are in XRI 2.0. Per the ABNF, both =drummond@microsoft.com and
@microsoft.com=drummond would parse into two subsegments.
=drummond@microsoft.com would parse into: 1) =drummond 2) @microsoft.com @microsoft.com=drummond would parse into: 1) @microsoft.com 2) =drummond =drummond+phone+home would parse into: 1) =drummond 2) +phone 3) +home In XRI resolution, each of these would produce its own XRD. I don’t
know why John thinks this is strange – an XRD can describe any resource, and certainly
my phone collection is a resource, and my home phone is a resource. =Drummond From: John Bradley
[mailto:jbradley@mac.com] Well thats a can of worms:) I think in Drummonds proposal + and $ also get to have XRD.
In the first segment the only place those
symbols formerly known as GCS would have
there conventional meaning is if they are attached to the
first sub segment. If they are the leading character of any other subsegment
they would be treated as * and the =, +, $ are only inferences to the
global concept. Remember I am the one opposed to the change unless there is
a good reason. So take any pro things I say with a grain of salt. The thing is that under that they will be treated as sub
segments by the authority server, so what gets passed? For =drummond@microsoft.com
the first subsegment is =drummond what is the second that get passed to
=drummonds's authority service? @microsoft.com *(@microsoft.com) microsoft.com So would =drummond*microsoft.com produce the same XRD as =drummond@microsoft.com? Could go ether way depending on how we define resolution. Yes having =drummond+phone have its own XRD seems sort of
funky to me as well. John B. On 24-Nov-08, at 10:23 AM, Victor Grey wrote: The confusion with email
addresses, social, technical or otherwise, is not the only problematic aspect
of the @ GCS character. |
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]