[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: RE: [xri] Normalization and Case Folding
|
Marty, I don't think it overlaps at all but it
definitely would *supplement* the
NAC XRI profile. In fact I think both the Introduction to XRI document and the
XRI Implementer's Guide document would be ideal companions to the NAC XRI
profile. So I much appreciate your help with these.
It may be good for us to schedule another whiteboard day as soon as there is
time so we can go over outlines or first drafts (thought right now that's
looking like early December for me). =Drummond From: Schleiff, Marty
[mailto:marty.schleiff@boeing.com] "Implementer's Guide" sounds
like it might have overlapping purposes with the NAC XRI Profile. So, I guess I
could be interested in helping. Marty.Schleiff@boeing.com;
CISSP From: Wil, Thanks for pointing this out. With the XRI
Syntax spec frozen, I think we have two options – publishing this
guidance as a best practices recommendation, or including it in the XRI
Implementer's Guide, the new deliverable we have in addition to the
Introduction to XRI document (because the new XRI Resolution draft will have
the non-normative material removed.) We need volunteers to work on the
Implementer's Guide. Do I see any hands up? If you're shy about responding on
the list, you can volunteer over the phone on this Friday's telecon (8:30AM PT
Friday, as usual). =Drummond From: Tan, William
[mailto:William.Tan@neustar.biz] One issue that recently came up during implementation is the
interaction between NFKC and case folding. For a small number of characters,
case folding is not closed under NFKC. Suppose Q(X) is a function defined by: Q(X) = NFKC(CaseFold(X)) The following property is NOT true for all strings: Q(Q(X)) == Q(X) Unicode standard recommends that additional mapping be
performed in order to guarantee the function to be closed [1]. These mappings
are well-defined and are given in the data file http://www.unicode.org/Public/3.2-Update/DerivedNormalizationProps-3.2.0.txt
under the FC_NFKC_Closure mapping. These mappings are also specified in
Stringprep (RFC3454) processing, and are in use by IDNA Nameprep. For XRI, it means that an application wishing to accurately
test for authority equivalence should apply the additional mapping when
performing case folding. If this is not followed, a pair of equivalent strings
that only differ in case may be falsely treated as different strings even
though case folding has been applied. Perhaps we should add an additional
recommendation to perform the additional mapping when doing case-less matching
of authority in section 2.5 of xri-syntax-V2.0-cd02 “Normalization and Comparison”. wil. [1]
http://www.unicode.org/versions/Unicode4.0.0/ch05.pdf#G21180 |
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]