--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lisp/mule/china-util.el	Wed Mar 13 08:54:06 2002 +0000
@@ -0,0 +1,162 @@
+;;; china-util.el --- utilities for Chinese -*- coding: iso-2022-7bit; -*-
+
+;; Copyright (C) 1995 Electrotechnical Laboratory, JAPAN.
+;; Licensed to the Free Software Foundation.
+
+;; Keywords: mule, multilingual, Chinese
+
+;; This file is part of XEmacs.
+
+;; XEmacs is free software; you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; XEmacs is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;; General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with XEmacs; see the file COPYING.  If not, write to the Free
+;; Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+;; 02111-1307, USA.
+
+;;; Synched up with: Emacs 21.0.103 (language/china-util.el).
+
+;;; Code:
+
+;; Hz/ZW encoding stuffs
+
+;; HZ is an encoding method for Chinese character set GB2312 used
+;; widely in Internet.  It is very similar to 7-bit environment of
+;; ISO-2022.  The difference is that HZ uses the sequence "~{" and
+;; "~}" for designating GB2312 and ASCII respectively, hence, it
+;; doesn't uses ESC (0x1B) code.
+
+;; ZW is another encoding method for Chinese character set GB2312.  It
+;; encodes Chinese characters line by line by starting each line with
+;; the sequence "zW".  It also uses only 7-bit as HZ.
+
+;; ISO-2022 escape sequence to designate GB2312.
+(defvar iso2022-gb-designation "\e$A")
+;; HZ escape sequence to designate GB2312.
+(defvar hz-gb-designnation "~{")
+;; ISO-2022 escape sequence to designate ASCII.
+(defvar iso2022-ascii-designation "\e(B")
+;; HZ escape sequence to designate ASCII.
+(defvar hz-ascii-designnation "~}")
+;; Regexp of ZW sequence to start GB2312.
+(defvar zw-start-gb "^zW")
+;; Regexp for start of GB2312 in an encoding mixture of HZ and ZW.
+(defvar hz/zw-start-gb
+  (concat hz-gb-designnation "\\|" zw-start-gb "\\|[^\0-\177]"))
+
+(defvar decode-hz-line-continuation nil
+  "Flag to tell if we should care line continuation convention of Hz.")
+
+(defconst hz-set-msb-table
+  (let ((str (make-string 127 0))
+	(i 0))
+    (while (< i 33)
+      (aset str i i)
+      (setq i (1+ i)))
+    (while (< i 127)
+      (aset str i (+ i 128))
+      (setq i (1+ i)))
+    str))
+
+;;;###autoload
+(defun decode-hz-region (beg end)
+  "Decode HZ/ZW encoded text in the current region.
+Return the length of resulting text."
+  (interactive "r")
+  (save-excursion
+    (save-restriction
+      (let (pos ch)
+	(narrow-to-region beg end)
+
+	;; We, at first, convert HZ/ZW to `euc-china',
+	;; then decode it.
+
+	;; "~\n" -> "\n", "~~" -> "~"
+	(goto-char (point-min))
+	(while (search-forward "~" nil t)
+	  (setq ch (following-char))
+	  (if (or (= ch ?\n) (= ch ?~)) (delete-char -1)))
+
+	;; "^zW...\n" -> Chinese GB2312
+	;; "~{...~}"  -> Chinese GB2312
+	(goto-char (point-min))
+	(setq beg nil)
+	(while (re-search-forward hz/zw-start-gb nil t)
+	  (setq pos (match-beginning 0)
+		ch (char-after pos))
+	  ;; Record the first position to start conversion.
+	  (or beg (setq beg pos))
+	  (end-of-line)
+	  (setq end (point))
+	  (if (>= ch 128)		; 8bit GB2312
+	      nil
+	    (goto-char pos)
+	    (delete-char 2)
+	    (setq end (- end 2))
+	    (if (= ch ?z)			; ZW -> euc-china
+		(progn
+		  (translate-region (point) end hz-set-msb-table)
+		  (goto-char end))
+	      (if (search-forward hz-ascii-designnation
+				  (if decode-hz-line-continuation nil end)
+				  t)
+		  (delete-char -2))
+	      (setq end (point))
+	      (translate-region pos (point) hz-set-msb-table))))
+	(if beg
+	    (decode-coding-region beg end 'euc-china)))
+      (- (point-max) (point-min)))))
+
+;;;###autoload
+(defun decode-hz-buffer ()
+  "Decode HZ/ZW encoded text in the current buffer."
+  (interactive)
+  (decode-hz-region (point-min) (point-max)))
+
+;;;###autoload
+(defun encode-hz-region (beg end)
+  "Encode the text in the current region to HZ.
+Return the length of resulting text."
+  (interactive "r")
+  (save-excursion
+    (save-restriction
+      (narrow-to-region beg end)
+
+      ;; "~" -> "~~"
+      (goto-char (point-min))
+      (while (search-forward "~" nil t)	(insert ?~))
+
+      ;; Chinese GB2312 -> "~{...~}"
+      (goto-char (point-min))
+      (if (re-search-forward "\\cc" nil t)
+	  (let (pos)
+	    (goto-char (setq pos (match-beginning 0)))
+	    (encode-coding-region pos (point-max) 'iso-2022-7bit)
+	    (goto-char pos)
+	    (while (search-forward iso2022-gb-designation nil t)
+	      (delete-char -3)
+	      (insert hz-gb-designnation))
+	    (goto-char pos)
+	    (while (search-forward iso2022-ascii-designation nil t)
+	      (delete-char -3)
+	      (insert hz-ascii-designnation))))
+      (- (point-max) (point-min)))))
+
+;;;###autoload
+(defun encode-hz-buffer ()
+  "Encode the text in the current buffer to HZ."
+  (interactive)
+  (encode-hz-region (point-min) (point-max)))
+
+;;
+(provide 'china-util)
+
+;;; china-util.el ends here