From: Yukihiro Matsumoto <matz@...>
Date: 2007-10-15T18:28:19+09:00
Subject: Re: Unicode: Progress?

Hi,

In message "Re: Unicode: Progress?"
    on Mon, 15 Oct 2007 17:30:06 +0900, murphy <murphy@rubychan.de> writes:

|The methods that should change the letter case (upcase, downcase,
|capitalize, swapcase) - shouldn't they work with Unicode by now?

Unfortunately, String case conversion will only work for ASCII region,
at least in 1.9, since there's no canonical way to convert cases
without script information, which may not be available all the time.
RDoc says:

     str.upcase   => new_str
  
  Returns a copy of <i>str</i> with all lowercase letters replaced with their
  uppercase counterparts. The operation is locale insensitive---only
  characters ``a'' to ``z'' are affected.
  Note: case replacement is effective only in ASCII region.

Locale (or script information) sensitive case conversion should be
accomplished by external Unicode library.  Maybe someday in the
future, String#upcase would work on umlauts.  We need more experience
on Unicode.

							matz.