[Bug 1850] New: [F&O] how do ranges work in case-insensitive mode?

http://www.w3.org/Bugs/Public/show_bug.cgi?id=1850

           Summary: [F&O] how do ranges work in case-insensitive mode?
           Product: XPath / XQuery / XSLT
           Version: Last Call drafts
          Platform: PC
        OS/Version: Windows 2000
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Functions and Operators
        AssignedTo: ashok.malhotra@oracle.com
        ReportedBy: fred.zemke@oracle.com
         QAContact: public-qt-comments@w3.org


Section 7.6.1.1 Flags describes a flag "i" which places F&O pattern searches
into case-insensitive mode.  Patterns are mostly described in XML Schema, and
include a capability to express a range in a bracket expression.  Since XML
Schema does not have case-insensitive matches, it does not define how a
case-insensitive range works.  This needs to be specified here.  

I can think of at least three possible definitions.  

1. The first algorithm is to form the case-insensitive range of 
the first and second operands, then add in anything that is a case-insensitive
version of something in this range.

2. In  the second algorithm, let f be the lowercase version of the first
operand, F be the uppercase equivalent of f, s be the lowercase version of
the second operand, and S the uppercase equivalent of s.  
Let m be the minimum of f and F, and let M be the maximum of s and S.  
The range is m-M, everything between m and M inclusive.

3. The third algorithm is the case-sensitive range f-s union with the 
case-sentitive range F-S.