[GHC] #14589: The isUpper function should return true for the '\9438' character

[GHC]

#14589: The isUpper function should return true for the '\9438' character
-------------------------------------+-------------------------------------
        Reporter:  mrkkrp            |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  libraries/base    |              Version:  8.2.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by nomeata):

 This is documented behavior. `isUpper` says:

 > Selects upper-case or title-case alphabetic Unicode characters
 (letters). Title case is used by a small number of letter ligatures like
 the single-character form of Lj.

 Note that is says “letter”, and the code in libraries/base/cbits/WCsubst.c
 explicitly selects only uppper-case and title-case letters.

 I see how this is a bit unfortunate, but I am sure we should not change
 the semantics of `isUpper` .

 Maybe we are missing a function? `isUpperAnything` or something?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14589#comment:2>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler