Re: Internal coding system - Need advice 22 v. 23

[Sebastian Rose <sebastian_rose@gmx.de>]

Kenichi Handa <handa@m17n.org> writes:
> In article <87pr7pzme8.fsf@gmx.de>, Sebastian Rose <sebastian_rose@gmx.de> writes:
>
>> To send unicode text to emacs via org-protocol, I wrote a function, that
>> decodes all those hex-encoded characters (e.g. `%C3%B6' is the German
>> Umlaut `ü'). That function `org-protocol-unhex-string' is defunned in
>> org/lisp/org-protocol.el. It works perfectly for emacs-23.
>
>> For emacs-22 this does _not_ work, however.
>
>> The problem occurs, if `char-to-string' is called with an unicode
>> character. E.g.
>
>>    (char-to-string 8211)
>
>> perfectly returns a dash in emacs-23. `org-protocol-unhex-string' works
>> like a charme for texts like those on http://www.welcome2japan.cn/ - in
>> emacs-23.
>
> Emacs-23's character code is a superset of Unicode, but
> Emacs-22's character code is not compatible with Unicode.
> To get Emacs-22's character code from Unicode character
> code, you must use decode-char function.  For instance, the
> above should be done by (string (decode-char 'ucs 8211)).


Ahh - OK. Seems to work perfect.



> And please note that Emacs-22 supports just a subset of
> Unicode (U+0000..U+33FF, U+E000..U+FFFF, and some of CJK
> characters contained in such legacy charsets as JISX0208,
> GB2312, KSC5601).


Well, there's nothing I could do about it except check for errors and
fail.


Thanks a lot for this explanation!



Best wishes


    Sebastian