In article <E1Kgh9x-0001GF-5j / x61.netlab.jp>,
  Yukihiro Matsumoto <matz / ruby-lang.org> writes:

> UTF-16 and UTF-8 are easier set, since they are semantically same.
> But how should we treat ISO-2022-JP for example?

I defined stateless-ISO-20222-JP which is semantically same
to ISO-2022-JP.  (Actually, it is a subset of Emacs-Mule.)

% ruby -ve '
p Encoding::Converter.asciicompat_encoding("ISO-2022-JP")
p Encoding::Converter.asciicompat_encoding("UTF-16BE")
p Encoding::Converter.asciicompat_encoding("UTF-16LE")
'
ruby 1.9.0 (2008-09-15 revision 19356) [i686-linux]
#<Encoding:stateless-ISO-2022-JP>
#<Encoding:UTF-8>
#<Encoding:UTF-8>

They are required to insert a error notice for conversion,
for example.
-- 
Tanaka Akira