From: Kenichi Handa <handa@m17n.org>
To: Eli Zaretskii <eliz@gnu.org>
Cc: emacs-devel@gnu.org
Subject: Re: Emacs 23 character code space
Date: Fri, 07 Nov 2008 20:52:37 +0900 [thread overview]
Message-ID: <E1KyPtF-0005Qa-6p@etlken.m17n.org> (raw)
In-Reply-To: <uy6zvsufb.fsf@gnu.org> (message from Eli Zaretskii on Fri, 07 Nov 2008 12:27:04 +0200)
In article <uy6zvsufb.fsf@gnu.org>, Eli Zaretskii <eliz@gnu.org> writes:
> Thanks. But I'm still a bit in the dark, as for how to describe this
> correctly and concisely. Do we actually use the range of codes
> between 0x110000 and 0x3FFF7F? If so, for what characters? If we do
> not use them now, are there some plans for using them in the future?
I wrote about the usage of that area in the thread "size of
emacs executable after unicode merge" as below.
> (0) At first, Emacs assigns a unique linear character code
> space in upper Unicode area (#x110000-) to each big
> character set (e.g. GB, JIS, KSC) (*see the note at the
> tail). The decoding of a character of a specific
> charset into this area is quite fast (done just by a few
> steps of arithmetic calculation). Encoding is the same
> too.
[...]
> *Note:
>
> The reason Emacs assigns those linear area is because such
> big charsets tend to have their own private use area, and we
> must keep a unique characte code for them. Those private
> characters are decoded and encoded without being mapped to
> Unicode are.
For example, the charset `japanese-jisx0208' is defined as
below.
(define-charset 'japanese-jisx0208
"JISX0208.1983/1990 Japanese Kanji: ISO-IR-87"
:short-name "JISX0208"
:long-name "JISX0208.1983/1990 (Japanese): ISO-IR-87"
:iso-final-char ?B
:emacs-mule-id 146
:code-space [33 126 33 126]
:code-offset #x140000
:unify-map "JISX0208")
So, for that charset, the code space for 8836 (=94x94)
characters are preserved in that upper area linearly from
#x140000. Then, most of the characters are mapped into
Unicode area by the map "JISX0208". The remaining
characters stay in this upper area.
---
Kenichi Handa
handa@ni.aist.go.jp
prev parent reply other threads:[~2008-11-07 11:52 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-01 14:20 Emacs 23 character code space Eli Zaretskii
2008-11-01 16:46 ` Eli Zaretskii
2008-11-03 1:34 ` Kenichi Handa
2008-11-03 12:45 ` Kenichi Handa
2008-11-03 20:13 ` Eli Zaretskii
2008-11-04 7:35 ` Kenichi Handa
2008-11-04 20:19 ` Eli Zaretskii
2008-11-05 12:27 ` Kenichi Handa
2008-11-05 18:23 ` Eli Zaretskii
2008-11-22 18:25 ` Eli Zaretskii
2008-11-26 1:41 ` Kenichi Handa
2008-11-26 4:13 ` Eli Zaretskii
2008-11-26 4:24 ` Kenichi Handa
2008-11-26 4:58 ` Kenichi Handa
2008-11-26 20:26 ` Eli Zaretskii
2008-11-26 22:52 ` Juanma Barranquero
2008-11-27 1:10 ` Stephen J. Turnbull
2008-11-27 1:35 ` Kenichi Handa
2008-11-26 20:18 ` Eli Zaretskii
2008-11-27 1:29 ` Kenichi Handa
2008-11-29 17:12 ` Eli Zaretskii
2008-12-02 5:40 ` Kenichi Handa
2008-11-28 13:19 ` Eli Zaretskii
2008-12-02 5:44 ` Kenichi Handa
2008-12-02 19:40 ` Eli Zaretskii
2008-11-29 12:01 ` Eli Zaretskii
2008-11-22 16:28 ` Eli Zaretskii
2008-11-23 4:16 ` Stefan Monnier
2008-11-23 11:22 ` Eli Zaretskii
2008-11-26 1:51 ` Kenichi Handa
2008-11-23 8:29 ` Ulrich Mueller
2008-11-23 11:11 ` Eli Zaretskii
2008-11-23 11:55 ` Ulrich Mueller
2008-11-24 3:06 ` Stefan Monnier
2008-11-26 1:31 ` Kenichi Handa
2008-11-22 17:03 ` New function: what-file-line, used when writing gdb script richardeng
2008-11-07 7:21 ` Emacs 23 character code space Kenichi Handa
2008-11-07 10:27 ` Eli Zaretskii
2008-11-07 11:52 ` Kenichi Handa [this message]
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