[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: RE: [xdi] abbreviation mechanism for XRI's
Bill, The labelled cross-reference bit might
better be handled by a $ letter added to the XRI Metadata spec, since this
doesn't require extending XRI syntax. Perhaps "$." or something like
that. So your cross-reference would be… ($./mylabel*(XRI-Authority)) Just an idea (and still I think only
useful if there are a lot of repeated authority or type XRIs, but I may not yet
fully understand this proposal). As for your question about xri:(foo*bar)*baz/
equivalent to xri:foo*bar*baz/? Is xri:foo*(bar*baz)/ equivalent to
xri:foo*bar*baz/ ? The answer is both cases is no. The easy way to think of it
is that from the standpoint of resolution, cross-references are literals. Insert
one and the value being resolved changes. For example, even xri://foo and xri://(foo) are not equivalent. They
MAY resolve to the same resource and thus be proved to be equivalent otherwise,
but not by XRI equivalence rules alone. =Drummond From: Barnhill William
[mailto:barnhill_william@bah.com] Thanks Dave. I see how we can use xrefs
to reference a segment group within the XRI, though that also might be prone to
cycles. I don't immediately see how to use xrefs to delineate a segment
group within an XRI and preserve the semantic meaning of the XRI. You,
Drummond, et al. know XRIs way better than I do, any ideas? Also, is there a XRI 2.1 or 2.0a rev planned, and is there
any possibility of the ref production going from xref = "("
(XRI-reference / IRI) ")" to xref = "("
(XRI-reference / IRI / "(" (label
[":" XRI-Authority ) ")" ) ")" or perhaps the more easier to read version xref = "("
(XRI-reference / IRI / lref ) ")" lref =
"(" (label [":" XRI-Authority ) ")" I would need a yacc run to make sure this parses without ambiguity. If
anyone has a yacc or similar xri grammar and wants to try the change I'd
appreciate it, as I won't be able to set that up until later this
weekend. Which brings up another XRI question: is xri:(foo*bar)*baz/ equivalent to xri:foo*bar*baz/ ? How about xri:foo*(bar*baz)/ equivalent to xri:foo*bar*baz/ ? This kind of brings to mind the previous discussion on an algebra for
XRI/XDI, but that's for another day. Bill From: Dave
McAlpin [mailto:Dave.McAlpin@epok.net] I agree with your analysis, i.e. square
brackets and braces aren’t available and can’t be used. The only
legal characters are in the xri-sub-delims production, and none of those are
“balanced”, like parens or brackets. I think your only option is to
use some form of cross-reference. Dave From: Barnhill William
[mailto:barnhill_william@bah.com] I did a little digging into the XRI 2.0
and IRI specs. "[" and "]" Are
xri-gen-delims, which does mean they are currently reserved, so this would
require an XRI spec mod. However, XRI makes no use of these chars, they're marked as
xri-gen-delims as they are reserved in IRI. Their use within IRI is for IP literals (ie. for IPv6+).
With that in mind "[" are prob out. Perhaps "{"
"}", which are not covered under XRI or IRI. Of course then we have
the problem of readability between "{}" and "()". Brackets
would be ideal, but then XDI addresses would not be XRIs, or XRIs
would not be IRIs, neither of which are acceptable I'd think. Another option, though somewhat ugly is
((label:oneormoresegments)) which also makes the grouping looking like a
special kind of cross-reference, which in a very loose sense it would seem to
be. The following would reference the labelled segments ((label)). This may be
the most workable as ")" is a xri-sub-delim, and it may be in line
with our current use of "(", though I'm leary of making
"("'s meaning depend on the character that follows it. Bill Barnhill Senior Consultant (XML, Emerging
Technologies, Web Services, Java) Booz | Allen | phone:+1.315.330.7386 From:
ad@ootao.com [mailto:ad@ootao.com]
Cool idea. $type is already one of our "default
dollar words" by virtue of -- |
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]