RE: [xri] RE: Simplified 1.1 path syntax (was Another perspective on GCS star issue)

["Drummond Reed" <drummond.reed@cordance.net>]

Good points, Mike. I agree with your rationale.

In the course of reviewing its requirements, what XDI really discovered was
its need for what XPath calls "multiple axis" addressing, i.e., the ability
to include an optional prefix of one or more characters before an identifier
that indicates which of several potential addressing axis the identifier
following the prefix is intended to address.

Since the addition of persistent identifiers in XRI to the current default
of reassignable identifiers in URIs already introduces a second "axis" of
addressing -- and one that I think should continue to be a fundamental
feature of XRIs -- what I'm wondering is whether in XRI 1.1 we should't be
trying to evolve the XRI 1.0 concept of subsegments into the more
generalized concept of axis prefixes.

For example, a simple way to do this in the ABNF would be:

xri = xri-auth [local-path] [query] [fragment] 
local-part = "/" *( axis-delims / xref ) *lchar [local-part] 
lchar = all legal XRI characters except /()?#

Note that this would mean an xref can also be used as an axis delimiter,
which is a perfect use of xrefs.

A slightly more elaborate form, which would fully support the XRI 1.0
concept of subsegments, would be to make it recursive, i.e.:

local-part = "/" * ( *( axis-delims / xref ) *lchar ) [local-part]