;;; viet-util.el --- utilities for Vietnamese -*- lexical-binding: t; -*-
;; Copyright (C) 1998, 2001-2021 Free Software Foundation, Inc.
;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
;; 2005, 2006, 2007, 2008, 2009, 2010, 2011
;; National Institute of Advanced Industrial Science and Technology (AIST)
;; Registration Number H14PRO021
;; Copyright (C) 2003
;; National Institute of Advanced Industrial Science and Technology (AIST)
;; Registration Number H13PRO009
;; 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 3 of the License, 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. If not, see <https://www.gnu.org/licenses/>.
;;; 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 5 different ways
;; for representing these characters: VISCII, TCVN-5712, VPS, VIQR,
;; and Unicode. VISCII, TCVN-5712 and VPS 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 mnemonic
;; encoding specification representing diacritical marks by following
;; ASCII characters.
;;; Code:
(defvar viet-viscii-nonascii-translation-table)
;;;###autoload
(defun viet-encode-viscii-char (char)
"Return VISCII character code of CHAR if appropriate."
(encode-char char 'viscii))
;; VIQR is a mnemonic encoding specification for Vietnamese.
;; It represents diacritical marks by ASCII characters as follows:
;; ------------+----------+--------
;; mark | mnemonic | example
;; ------------+----------+---------
;; breve | ( | a( -> ă
;; circumflex | ^ | a^ -> â
;; horn | + | o+ -> ơ
;; ------------+----------+---------
;; acute | ' | a' -> á
;; grave | ` | a` -> à
;; hook above | ? | a? -> ả
;; tilde | ~ | a~ -> ã
;; dot below | . | a. -> ạ
;; ------------+----------+---------
;; d bar | dd | dd -> đ
;; ------------+----------+---------
(defvar viet-viqr-alist
'(;; lowercase
(?ắ . "a('") ; 161
(?ằ . "a(`") ; 162
(?ặ . "a(.") ; 163
(?ấ . "a^'") ; 164
(?ầ . "a^`") ; 165
(?ẩ . "a^?") ; 166
(?ậ . "a^.") ; 167
(?ẽ . "e~") ; 168
(?ẹ . "e.") ; 169
(?ế . "e^'") ; 170
(?ề . "e^`") ; 171
(?ể . "e^?") ; 172
(?ễ . "e^~") ; 173
(?ệ . "e^.") ; 174
(?ố . "o^'") ; 175
(?ồ . "o^`") ; 176
(?ổ . "o^?") ; 177
(?ỗ . "o^~") ; 178
(?ộ . "o^.") ; 181
(?ờ . "o+`") ; 182
(?ở . "o+?") ; 183
(?ị . "i.") ; 184
(?ơ . "o+") ; 189
(?ớ . "o+'") ; 190
(?ẳ . "a(?") ; 198
(?ẵ . "a(~") ; 199
(?ỳ . "y`") ; 207
(?ứ . "u+'") ; 209
(?ạ . "a.") ; 213
(?ỷ . "y?") ; 214
(?ừ . "u+`") ; 215
(?ử . "u+?") ; 216
(?ỹ . "y~") ; 219
(?ỵ . "y.") ; 220
(?ỡ . "o+~") ; 222
(?ư . "u+") ; 223
(?à . "a`") ; 224
(?á . "a'") ; 225
(?â . "a^") ; 226
(?ã . "a~") ; 227
(?ả . "a?") ; 228
(?ă . "a(") ; 229
(?ữ . "u+~") ; 230
(?ẫ . "a^~") ; 231
(?è . "e`") ; 232
(?é . "e'") ; 233
(?ê . "e^") ; 234
(?ẻ . "e?") ; 235
(?ì . "i`") ; 236
(?í . "i'") ; 237
(?ĩ . "i~") ; 238
(?ỉ . "i?") ; 239
(?đ . "dd") ; 240
(?ự . "u+.") ; 241
(?ò . "o`") ; 242
(?ó . "o'") ; 243
(?ô . "o^") ; 244
(?õ . "o~") ; 245
(?ỏ . "o?") ; 246
(?ọ . "o.") ; 247
(?ụ . "u.") ; 248
(?ù . "u`") ; 249
(?ú . "u'") ; 250
(?ũ . "u~") ; 251
(?ủ . "u?") ; 252
(?ý . "y'") ; 253
(?ợ . "o+.") ; 254
;; upper case
(?Ắ . "A('") ; 161
(?Ằ . "A(`") ; 162
(?Ặ . "A(.") ; 163
(?Ấ . "A^'") ; 164
(?Ầ . "A^`") ; 165
(?Ẩ . "A^?") ; 166
(?Ậ . "A^.") ; 167
(?Ẽ . "E~") ; 168
(?Ẹ . "E.") ; 169
(?Ế . "E^'") ; 170
(?Ề . "E^`") ; 171
(?Ể . "E^?") ; 172
(?Ễ . "E^~") ; 173
(?Ệ . "E^.") ; 174
(?Ố . "O^'") ; 175
(?Ồ . "O^`") ; 176
(?Ổ . "O^?") ; 177
(?Ỗ . "O^~") ; 178
(?Ộ . "O^.") ; 181
(?Ờ . "O+`") ; 182
(?Ở . "O+?") ; 183
(?Ị . "I.") ; 184
(?Ơ . "O+") ; 189
(?Ớ . "O+'") ; 190
(?Ẳ . "A(?") ; 198
(?Ẵ . "A(~") ; 199
(?Ỳ . "Y`") ; 207
(?Ứ . "U+'") ; 209
(?Ạ . "A.") ; 213
(?Ỷ . "Y?") ; 214
(?Ừ . "U+`") ; 215
(?Ử . "U+?") ; 216
(?Ỹ . "Y~") ; 219
(?Ỵ . "Y.") ; 220
(?Ỡ . "O+~") ; 222
(?Ư . "U+") ; 223
(?À . "A`") ; 224
(?Á . "A'") ; 225
(? . "A^") ; 226
(?Ã . "A~") ; 227
(?Ả . "A?") ; 228
(?Ă . "A(") ; 229
(?Ữ . "U+~") ; 230
(?Ẫ . "A^~") ; 231
(?È . "E`") ; 232
(?É . "E'") ; 233
(?Ê . "E^") ; 234
(?Ẻ . "E?") ; 235
(?Ì . "I`") ; 236
(?Í . "I'") ; 237
(?Ĩ . "I~") ; 238
(?Ỉ . "I?") ; 239
(?Đ . "DD") ; 240
(?Đ . "dD") ; 240
(?Đ . "Dd") ; 240
(?Ự . "U+.") ; 241
(?Ò . "O`") ; 242
(?Ó . "O'") ; 243
(?Ô . "O^") ; 244
(?Õ . "O~") ; 245
(?Ỏ . "O?") ; 246
(?Ọ . "O.") ; 247
(?Ụ . "U.") ; 248
(?Ù . "U`") ; 249
(?Ú . "U'") ; 250
(?Ũ . "U~") ; 251
(?Ủ . "U?") ; 252
(?Ý . "Y'") ; 253
(?Ợ . "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 characters.
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 characters."
(interactive)
(viet-decode-viqr-region (point-min) (point-max)))
;;;###autoload
(defun viet-encode-viqr-region (from to)
"Convert Vietnamese characters 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 characters 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)))
(set-buffer (generate-new-buffer " *temp*"))
(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