--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lisp/language/viet-util.el	Mon Aug 13 10:00:02 2007 +0200
@@ -0,0 +1,296 @@
+;;; viet-util.el ---  utilities for Vietnamese
+
+;; Copyright (C) 1995 Electrotechnical Laboratory, JAPAN.
+;; Licensed to the Free Software Foundation.
+
+;; Keywords: mule, multilingual, Vietnamese
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs 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.
+
+;; GNU Emacs 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 GNU Emacs; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;; Commentary:
+
+;; Vietnamese uses ASCII characters and additional 134 unique
+;; characters (these are Latin alphabets with various diacritical and
+;; tone marks).  As far as I know, Vietnamese now has 4 different ways
+;; for representing these characters: VISCII, VSCII, VIQR, and
+;; Unicode.  VISCII and VSCII are simple 1-byte code which assigns 134
+;; unique characters in control-code area (0x00..0x1F) and right half
+;; area (0x80..0xFF).  VIQR is a menmonic encoding specification
+;; representing diacritical marks by following ASCII characters.
+
+;;; Code:
+
+;;;###autoload
+(defun setup-vietnamese-environment ()
+  "Setup multilingual environment (MULE) for Vietnamese VISCII users."
+  (interactive)
+  (setup-8-bit-environment "Vietnamese" nil 'vietnamese-viscii
+			   "vietnamese-viqr")
+  (setq coding-category-raw-text 'vietnamese-viscii))
+
+;; VIQR is a menmonic encoding specification for Vietnamese.
+;; It represents diacritical marks by ASCII characters as follows:
+;; ------------+----------+--------
+;;     mark    | mnemonic | example
+;; ------------+----------+---------
+;;    breve    |    (     | a( -> ,1e(B
+;;  circumflex |    ^     | a^ -> ,1b(B
+;;    horn     |    +     | o+ -> ,1=(B
+;; ------------+----------+---------
+;;    acute    |    '     | a' -> ,1a(B
+;;    grave    |    `     | a` -> ,1`(B
+;;  hook above |    ?     | a? -> ,1d(B
+;;    tilde    |    ~     | a~ -> ,1c(B
+;;   dot below |    .     | a. -> ,1U(B
+;; ------------+----------+---------
+;;    d bar    |   dd     | dd -> ,1p(B
+;; ------------+----------+---------
+
+(defvar viet-viqr-alist
+  '(;; lowercase
+    (?,1!(B . "a('")			; 161
+    (?,1"(B . "a(`")			; 162
+    (?,1#(B . "a(.")			; 163
+    (?,1$(B . "a^'")			; 164
+    (?,1%(B . "a^`")			; 165
+    (?,1&(B . "a^?")			; 166
+    (?,1'(B . "a^.")			; 167
+    (?,1((B . "e~")				; 168
+    (?,1)(B . "e.")				; 169
+    (?,1*(B . "e^'")			; 170
+    (?,1+(B . "e^`")			; 171
+    (?,1,(B . "e^?")			; 172
+    (?,1-(B . "e^~")			; 173
+    (?,1.(B . "e^.")			; 174
+    (?,1/(B . "o^'")			; 175
+    (?,10(B . "o^`")			; 176
+    (?,11(B . "o^?")			; 177
+    (?,12(B . "o^~")			; 178
+    (?,15(B . "o^.")			; 181
+    (?,16(B . "o+`")			; 182
+    (?,17(B . "o+?")			; 183
+    (?,18(B . "i.")				; 184
+    (?,1=(B . "o+")				; 189
+    (?,1>(B . "o+'")			; 190
+    (?,1F(B . "a(?")			; 198
+    (?,1G(B . "a(~")			; 199
+    (?,1O(B . "y`")				; 207
+    (?,1Q(B . "u+'")			; 209
+    (?,1U(B . "a.")				; 213
+    (?,1V(B . "y?")				; 214
+    (?,1W(B . "u+`")			; 215
+    (?,1X(B . "u+?")			; 216
+    (?,1[(B . "y~")				; 219
+    (?,1\(B . "y.")				; 220
+    (?,1^(B . "o+~")			; 222
+    (?,1_(B . "u+")				; 223
+    (?,1`(B . "a`")				; 224
+    (?,1a(B . "a'")				; 225
+    (?,1b(B . "a^")				; 226
+    (?,1c(B . "a~")				; 227
+    (?,1d(B . "a?")				; 228
+    (?,1e(B . "a(")				; 229
+    (?,1f(B . "u+~")			; 230
+    (?,1g(B . "a^~")			; 231
+    (?,1h(B . "e`")				; 232
+    (?,1i(B . "e'")				; 233
+    (?,1j(B . "e^")				; 234
+    (?,1k(B . "e?")				; 235
+    (?,1l(B . "i`")				; 236
+    (?,1m(B . "i'")				; 237
+    (?,1n(B . "i~")				; 238
+    (?,1o(B . "i?")				; 239
+    (?,1p(B . "dd")				; 240
+    (?,1q(B . "u+.")			; 241
+    (?,1r(B . "o`")				; 242
+    (?,1s(B . "o'")				; 243
+    (?,1t(B . "o^")				; 244
+    (?,1u(B . "o~")				; 245
+    (?,1v(B . "o?")				; 246
+    (?,1w(B . "o.")				; 247
+    (?,1x(B . "u.")				; 248
+    (?,1y(B . "u`")				; 249
+    (?,1z(B . "u'")				; 250
+    (?,1{(B . "u~")				; 251
+    (?,1|(B . "u?")				; 252
+    (?,1}(B . "y'")				; 253
+    (?,1~(B . "o+.")			; 254
+
+    ;; upper case
+    (?,2!(B . "A('")			; 161
+    (?,2"(B . "A(`")			; 162
+    (?,2#(B . "A(.")			; 163
+    (?,2$(B . "A^'")			; 164
+    (?,2%(B . "A^`")			; 165
+    (?,2&(B . "A^?")			; 166
+    (?,2'(B . "A^.")			; 167
+    (?,2((B . "E~")				; 168
+    (?,2)(B . "E.")				; 169
+    (?,2*(B . "E^'")			; 170
+    (?,2+(B . "E^`")			; 171
+    (?,2,(B . "E^?")			; 172
+    (?,2-(B . "E^~")			; 173
+    (?,2.(B . "E^.")			; 174
+    (?,2/(B . "O^'")			; 175
+    (?,20(B . "O^`")			; 176
+    (?,21(B . "O^?")			; 177
+    (?,22(B . "O^~")			; 178
+    (?,25(B . "O^.")			; 181
+    (?,26(B . "O+`")			; 182
+    (?,27(B . "O+?")			; 183
+    (?,28(B . "I.")				; 184
+    (?,2=(B . "O+")				; 189
+    (?,2>(B . "O+'")			; 190
+    (?,2F(B . "A(?")			; 198
+    (?,2G(B . "A(~")			; 199
+    (?,2O(B . "Y`")				; 207
+    (?,2Q(B . "U+'")			; 209
+    (?,2U(B . "A.")				; 213
+    (?,2V(B . "Y?")				; 214
+    (?,2W(B . "U+`")			; 215
+    (?,2X(B . "U+?")			; 216
+    (?,2[(B . "Y~")				; 219
+    (?,2\(B . "Y.")				; 220
+    (?,2^(B . "O+~")			; 222
+    (?,2_(B . "U+")				; 223
+    (?,2`(B . "A`")				; 224
+    (?,2a(B . "A'")				; 225
+    (?,2b(B . "A^")				; 226
+    (?,2c(B . "A~")				; 227
+    (?,2d(B . "A?")				; 228
+    (?,2e(B . "A(")				; 229
+    (?,2f(B . "U+~")			; 230
+    (?,2g(B . "A^~")			; 231
+    (?,2h(B . "E`")				; 232
+    (?,2i(B . "E'")				; 233
+    (?,2j(B . "E^")				; 234
+    (?,2k(B . "E?")				; 235
+    (?,2l(B . "I`")				; 236
+    (?,2m(B . "I'")				; 237
+    (?,2n(B . "I~")				; 238
+    (?,2o(B . "I?")				; 239
+    (?,2p(B . "DD")				; 240
+    (?,2p(B . "dD")				; 240
+    (?,2p(B . "Dd")				; 240
+    (?,2q(B . "U+.")			; 241
+    (?,2r(B . "O`")				; 242
+    (?,2s(B . "O'")				; 243
+    (?,2t(B . "O^")				; 244
+    (?,2u(B . "O~")				; 245
+    (?,2v(B . "O?")				; 246
+    (?,2w(B . "O.")				; 247
+    (?,2x(B . "U.")				; 248
+    (?,2y(B . "U`")				; 249
+    (?,2z(B . "U'")				; 250
+    (?,2{(B . "U~")				; 251
+    (?,2|(B . "U?")				; 252
+    (?,2}(B . "Y'")				; 253
+    (?,2~(B . "O+.")			; 254
+
+    ;; escape from composition
+    (?\( . "\\(")			; breve (left parenthesis)
+    (?^ . "\\^")			; circumflex (caret)
+    (?+ . "\\+")			; horn (plus sign)
+    (?' . "\\'")			; acute (apostrophe)
+    (?` . "\\`")			; grave (backquote)
+    (?? . "\\?")			; hook above (question mark)
+    (?~ . "\\~")			; tilde (tilde)
+    (?. . "\\.")			; dot below (period)
+    (?d . "\\d")			; d-bar (d)
+    (?\\ . "\\\\")			; literal backslash
+    )
+  "Alist of Vietnamese characters vs corresponding `VIQR' string.")
+
+;; Regular expression matching single Vietnamese character represented
+;; by VIQR.
+(defconst viqr-regexp
+  "[aeiouyAEIOUY]\\([(^+]?['`?~.]\\|[(^+]\\)\\|[Dd][Dd]")
+
+;;;###autoload
+(defun viet-decode-viqr-region (from to)
+  "Convert `VIQR' mnemonics of the current region to Vietnamese characaters.
+When called from a program, expects two arguments,
+positions (integers or markers) specifying the stretch of the region."
+  (interactive "r")
+  (save-restriction
+    (narrow-to-region from to)
+    (goto-char (point-min))
+    (while (re-search-forward viqr-regexp nil t)
+      (let* ((viqr (buffer-substring (match-beginning 0) (match-end 0)))
+	     (ch (car (rassoc viqr viet-viqr-alist))))
+	(if ch
+	    (progn
+	      (delete-region (match-beginning 0) (match-end 0))
+	      (insert ch)))))))
+
+;;;###autoload
+(defun viet-decode-viqr-buffer ()
+  "Convert `VIQR' mnemonics of the current buffer to Vietnamese characaters."
+  (interactive)
+  (viet-decode-viqr-region (point-min) (point-max)))
+
+;;;###autoload
+(defun viet-encode-viqr-region (from to)
+  "Convert Vietnamese characaters of the current region to `VIQR' mnemonics.
+When called from a program, expects two arguments,
+positions (integers or markers) specifying the stretch of the region."
+  (interactive "r")
+  (save-restriction
+    (narrow-to-region from to)
+    (goto-char (point-min))
+    (while (re-search-forward "\\cv" nil t)
+      (let* ((ch (preceding-char))
+	     (viqr (cdr (assq ch viet-viqr-alist))))
+	(if viqr
+	    (progn
+	      (delete-char -1)
+	      (insert viqr)))))))
+
+;;;###autoload
+(defun viet-encode-viqr-buffer ()
+  "Convert Vietnamese characaters of the current buffer to `VIQR' mnemonics."
+  (interactive)
+  (viet-encode-viqr-region (point-min) (point-max)))
+
+;;;###autoload
+(defun viqr-post-read-conversion (len)
+  (save-excursion
+    (save-restriction
+      (narrow-to-region (point) (+ (point) len))
+      (let ((buffer-modified-p (buffer-modified-p)))
+	(viet-decode-viqr-region (point-min) (point-max))
+	(set-buffer-modified-p buffer-modified-p)
+	(- (point-max) (point-min))))))
+
+;;;###autoload
+(defun viqr-pre-write-conversion (from to)
+  (let ((old-buf (current-buffer))
+	(work-buf (get-buffer-create " *viet-work*")))
+    (set-buffer work-buf)
+    (erase-buffer)
+    (if (stringp from)
+	(insert from)
+      (insert-buffer-substring old-buf from to))
+    (viet-encode-viqr-region (point-min) (point-max))
+    ;; Should return nil as annotations.
+    nil))
+
+;;;
+(provide 'viet-util)
+
+;;; viet-util.el ends here