lisp/language/thai-util.el

   1 ;;; thai-util.el --- utilities for Thai -*- coding: iso-2022-7bit; -*-
   2
   3 ;; Copyright (C) 1995, 1997, 1998, 1999, 2000, 2001, 2005
   4 ;;   National Institute of Advanced Industrial Science and Technology (AIST)
   5 ;;   Registration Number H14PRO021
   6 ;; Copyright (C) 2000, 2001 Free Software Foundation, Inc.
   7
   8 ;; Keywords: mule, multilingual, thai
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 2, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25 ;; Boston, MA 02111-1307, USA.
  26
  27 ;;; Commentary:
  28
  29 ;;; Code:
  30
  31 ;; Setting information of Thai characters.
  32
  33 (defconst thai-category-table (make-category-table))
  34 (define-category ?c "Thai consonant" thai-category-table)
  35 (define-category ?v "Thai upper/lower vowel" thai-category-table)
  36 (define-category ?t "Thai tone mark" thai-category-table)
  37 (define-category ?u "Thai tone mark and upper sign" thai-category-table)
  38 (define-category ?I "THAI CHARACTER SARA I" thai-category-table)
  39 (define-category ?U "THAI CHARACTER THANTHAKHAT" thai-category-table)
  40
  41 ;; The general composing rules are as follows:
  42 ;;
  43 ;;                          T
  44 ;;       V        U         V                  U
  45 ;; CV -> C, CU -> C, CVT -> C, Cv -> C, CvU -> C
  46 ;;                                   v         v
  47 ;;
  48 ;; where C: consonant, V: vowel upper, v: vowel lower,
  49 ;;       T: tone mark, U: tone mark and upper sign.
  50 ;; Special rule: The sign `\e,Tl\e(B' can be put on the vowel `\e,TT\e(B'.
  51
  52
  53 (defvar thai-composition-pattern
  54   "\\cc\\(\\cu\\|\\cI\\cU\\|\\cv\\ct?\\)\\|\\cv\\ct\\|\\cI\\cU"
  55   "Regular expression matching a Thai composite sequence.")
  56
  57 (defun thai-self-insert-command (&optional n)
  58   "Insert the Thai character you type.
  59 The character will be composed with the surrounding Thai character
  60 if necessary."
  61   (interactive "*p")
  62   (let ((pos (point))
  63         category-set ch)
  64     (self-insert-command n)
  65     (or thai-auto-composition-mode
  66         (thai-auto-composition (1- (point)) (point) 0))))
  67
  68 (let ((l '((?\e,T!\e(B consonant "LETTER KO KAI")                         ; 0xA1
  69            (?\e,T"\e(B consonant "LETTER KHO KHAI")                               ; 0xA2
  70            (?\e,T#\e(B consonant "LETTER KHO KHUAT")                              ; 0xA3
  71            (?\e,T$\e(B consonant "LETTER KHO KHWAI")                              ; 0xA4
  72            (?\e,T%\e(B consonant "LETTER KHO KHON")                               ; 0xA5
  73            (?\e,T&\e(B consonant "LETTER KHO RAKHANG")                            ; 0xA6
  74            (?\e,T'\e(B consonant "LETTER NGO NGU")                                ; 0xA7
  75            (?\e,T(\e(B consonant "LETTER CHO CHAN")                               ; 0xA8
  76            (?\e,T)\e(B consonant "LETTER CHO CHING")                              ; 0xA9
  77            (?\e,T*\e(B consonant "LETTER CHO CHANG")                              ; 0xAA
  78            (?\e,T+\e(B consonant "LETTER SO SO")                          ; 0xAB
  79            (?\e,T,\e(B consonant "LETTER CHO CHOE")                               ; 0xAC
  80            (?\e,T-\e(B consonant "LETTER YO YING")                                ; 0xAD
  81            (?\e,T.\e(B consonant "LETTER DO CHADA")                               ; 0xAE
  82            (?\e,T/\e(B consonant "LETTER TO PATAK")                               ; 0xAF
  83            (?\e,T0\e(B consonant "LETTER THO THAN")                               ; 0xB0
  84            (?\e,T1\e(B consonant "LETTER THO NANGMONTHO")                 ; 0xB1
  85            (?\e,T2\e(B consonant "LETTER THO PHUTHAO")                            ; 0xB2
  86            (?\e,T3\e(B consonant "LETTER NO NEN")                         ; 0xB3
  87            (?\e,T4\e(B consonant "LETTER DO DEK")                         ; 0xB4
  88            (?\e,T5\e(B consonant "LETTER TO TAO")                         ; 0xB5
  89            (?\e,T6\e(B consonant "LETTER THO THUNG")                              ; 0xB6
  90            (?\e,T7\e(B consonant "LETTER THO THAHAN")                             ; 0xB7
  91            (?\e,T8\e(B consonant "LETTER THO THONG")                              ; 0xB8
  92            (?\e,T9\e(B consonant "LETTER NO NU")                          ; 0xB9
  93            (?\e,T:\e(B consonant "LETTER BO BAIMAI")                              ; 0xBA
  94            (?\e,T;\e(B consonant "LETTER PO PLA")                         ; 0xBB
  95            (?\e,T<\e(B consonant "LETTER PHO PHUNG")                              ; 0xBC
  96            (?\e,T=\e(B consonant "LETTER FO FA")                          ; 0xBD
  97            (?\e,T>\e(B consonant "LETTER PHO PHAN")                               ; 0xBE
  98            (?\e,T?\e(B consonant "LETTER FO FAN")                         ; 0xBF
  99            (?\e,T@\e(B consonant "LETTER PHO SAMPHAO")                            ; 0xC0
 100            (?\e,TA\e(B consonant "LETTER MO MA")                          ; 0xC1
 101            (?\e,TB\e(B consonant "LETTER YO YAK")                         ; 0xC2
 102            (?\e,TC\e(B consonant "LETTER RO RUA")                         ; 0xC3
 103            (?\e,TD\e(B vowel-base "LETTER RU (Pali vowel letter)")                ; 0xC4
 104            (?\e,TE\e(B consonant "LETTER LO LING")                                ; 0xC5
 105            (?\e,TF\e(B vowel-base "LETTER LU (Pali vowel letter)")                ; 0xC6
 106            (?\e,TG\e(B consonant "LETTER WO WAEN")                                ; 0xC7
 107            (?\e,TH\e(B consonant "LETTER SO SALA")                                ; 0xC8
 108            (?\e,TI\e(B consonant "LETTER SO RUSI")                                ; 0xC9
 109            (?\e,TJ\e(B consonant "LETTER SO SUA")                         ; 0xCA
 110            (?\e,TK\e(B consonant "LETTER HO HIP")                         ; 0xCB
 111            (?\e,TL\e(B consonant "LETTER LO CHULA")                               ; 0xCC
 112            (?\e,TM\e(B consonant "LETTER O ANG")                          ; 0xCD
 113            (?\e,TN\e(B consonant "LETTER HO NOK HUK")                             ; 0xCE
 114            (?\e,TO\e(B special "PAI YAN NOI (abbreviation)")                      ; 0xCF
 115            (?\e,TP\e(B vowel-base "VOWEL SIGN SARA A")                            ; 0xD0
 116            (?\e,TQ\e(B vowel-upper "VOWEL SIGN MAI HAN-AKAT N/S-T")               ; 0xD1
 117            (?\e,TR\e(B vowel-base "VOWEL SIGN SARA AA")                           ; 0xD2
 118            (?\e,TS\e(B vowel-base "VOWEL SIGN SARA AM")                           ; 0xD3
 119            (?\e,TT\e(B vowel-upper "VOWEL SIGN SARA I N/S-T")                     ; 0xD4
 120            (?\e,TU\e(B vowel-upper "VOWEL SIGN SARA II N/S-T")                    ; 0xD5
 121            (?\e,TV\e(B vowel-upper "VOWEL SIGN SARA UE N/S-T")                    ; 0xD6
 122            (?\e,TW\e(B vowel-upper "VOWEL SIGN SARA UEE N/S-T")                   ; 0xD7
 123            (?\e,TX\e(B vowel-lower "VOWEL SIGN SARA U N/S-B")                     ; 0xD8
 124            (?\e,TY\e(B vowel-lower "VOWEL SIGN SARA UU N/S-B")                    ; 0xD9
 125            (?\e,TZ\e(B vowel-lower "VOWEL SIGN PHINTHU N/S-B (Pali virama)")      ; 0xDA
 126            (?\e,T[\e(B invalid nil)                                               ; 0xDA
 127            (?\e,T\\e(B invalid nil)                                               ; 0xDC
 128            (?\e,T]\e(B invalid nil)                                               ; 0xDC
 129            (?\e,T^\e(B invalid nil)                                               ; 0xDC
 130            (?\e,T_\e(B special "BAHT SIGN (currency symbol)")                     ; 0xDF
 131            (?\e,T`\e(B vowel-base "VOWEL SIGN SARA E")                            ; 0xE0
 132            (?\e,Ta\e(B vowel-base "VOWEL SIGN SARA AE")                           ; 0xE1
 133            (?\e,Tb\e(B vowel-base "VOWEL SIGN SARA O")                            ; 0xE2
 134            (?\e,Tc\e(B vowel-base "VOWEL SIGN SARA MAI MUAN")                     ; 0xE3
 135            (?\e,Td\e(B vowel-base "VOWEL SIGN SARA MAI MALAI")                    ; 0xE4
 136            (?\e,Te\e(B vowel-base "LAK KHANG YAO")                                ; 0xE5
 137            (?\e,Tf\e(B special "MAI YAMOK (repetion)")                            ; 0xE6
 138            (?\e,Tg\e(B sign-upper "VOWEL SIGN MAI TAI KHU N/S-T")         ; 0xE7
 139            (?\e,Th\e(B tone "TONE MAI EK N/S-T")                          ; 0xE8
 140            (?\e,Ti\e(B tone "TONE MAI THO N/S-T")                         ; 0xE9
 141            (?\e,Tj\e(B tone "TONE MAI TRI N/S-T")                         ; 0xEA
 142            (?\e,Tk\e(B tone "TONE MAI CHATTAWA N/S-T")                            ; 0xEB
 143            (?\e,Tl\e(B sign-upper "THANTHAKHAT N/S-T (cancellation mark)")        ; 0xEC
 144            (?\e,Tm\e(B sign-upper "NIKKHAHIT N/S-T (final nasal)")                ; 0xED
 145            (?\e,Tn\e(B sign-upper "YAMAKKAN N/S-T")                               ; 0xEE
 146            (?\e,To\e(B special "FONRMAN")                                 ; 0xEF
 147            (?\e,Tp\e(B special "DIGIT ZERO")                                      ; 0xF0
 148            (?\e,Tq\e(B special "DIGIT ONE")                                       ; 0xF1
 149            (?\e,Tr\e(B special "DIGIT TWO")                                       ; 0xF2
 150            (?\e,Ts\e(B special "DIGIT THREE")                                     ; 0xF3
 151            (?\e,Tt\e(B special "DIGIT FOUR")                                      ; 0xF4
 152            (?\e,Tu\e(B special "DIGIT FIVE")                                      ; 0xF5
 153            (?\e,Tv\e(B special "DIGIT SIX")                                       ; 0xF6
 154            (?\e,Tw\e(B special "DIGIT SEVEN")                                     ; 0xF7
 155            (?\e,Tx\e(B special "DIGIT EIGHT")                                     ; 0xF8
 156            (?\e,Ty\e(B special "DIGIT NINE")                                      ; 0xF9
 157            (?\e,Tz\e(B special "ANGKHANKHU (ellipsis)")                           ; 0xFA
 158            (?\e,T{\e(B special "KHOMUT (beginning of religious texts)")           ; 0xFB
 159            (?\e,T|\e(B invalid nil)                                               ; 0xFC
 160            (?\e,T}\e(B invalid nil)                                               ; 0xFD
 161            (?\e,T~\e(B invalid nil)                                               ; 0xFE
 162
 163            ;; Unicode equivalents
 164            (?\e$,1Ba\e(B consonant "LETTER KO KAI")
 165            (?\e$,1Bb\e(B consonant "LETTER KHO KHAI")
 166            (?\e$,1Bc\e(B consonant "LETTER KHO KHUAT")
 167            (?\e$,1Bd\e(B consonant "LETTER KHO KHWAI")
 168            (?\e$,1Be\e(B consonant "LETTER KHO KHON")
 169            (?\e$,1Bf\e(B consonant "LETTER KHO RAKHANG")
 170            (?\e$,1Bg\e(B consonant "LETTER NGO NGU")
 171            (?\e$,1Bh\e(B consonant "LETTER CHO CHAN")
 172            (?\e$,1Bi\e(B consonant "LETTER CHO CHING")
 173            (?\e$,1Bj\e(B consonant "LETTER CHO CHANG")
 174            (?\e$,1Bk\e(B consonant "LETTER SO SO")
 175            (?\e$,1Bl\e(B consonant "LETTER CHO CHOE")
 176            (?\e$,1Bm\e(B consonant "LETTER YO YING")
 177            (?\e$,1Bn\e(B consonant "LETTER DO CHADA")
 178            (?\e$,1Bo\e(B consonant "LETTER TO PATAK")
 179            (?\e$,1Bp\e(B consonant "LETTER THO THAN")
 180            (?\e$,1Bq\e(B consonant "LETTER THO NANGMONTHO")
 181            (?\e$,1Br\e(B consonant "LETTER THO PHUTHAO")
 182            (?\e$,1Bs\e(B consonant "LETTER NO NEN")
 183            (?\e$,1Bt\e(B consonant "LETTER DO DEK")
 184            (?\e$,1Bu\e(B consonant "LETTER TO TAO")
 185            (?\e$,1Bv\e(B consonant "LETTER THO THUNG")
 186            (?\e$,1Bw\e(B consonant "LETTER THO THAHAN")
 187            (?\e$,1Bx\e(B consonant "LETTER THO THONG")
 188            (?\e$,1By\e(B consonant "LETTER NO NU")
 189            (?\e$,1Bz\e(B consonant "LETTER BO BAIMAI")
 190            (?\e$,1B{\e(B consonant "LETTER PO PLA")
 191            (?\e$,1B|\e(B consonant "LETTER PHO PHUNG")
 192            (?\e$,1B}\e(B consonant "LETTER FO FA")
 193            (?\e$,1B~\e(B consonant "LETTER PHO PHAN")
 194            (?\e$,1B\x7f\e(B consonant "LETTER FO FAN")
 195            (?\e$,1C \e(B consonant "LETTER PHO SAMPHAO")
 196            (?\e$,1C!\e(B consonant "LETTER MO MA")
 197            (?\e$,1C"\e(B consonant "LETTER YO YAK")
 198            (?\e$,1C#\e(B consonant "LETTER RO RUA")
 199            (?\e$,1C$\e(B vowel-base "LETTER RU (Pali vowel letter)")
 200            (?\e$,1C%\e(B consonant "LETTER LO LING")
 201            (?\e$,1C&\e(B vowel-base "LETTER LU (Pali vowel letter)")
 202            (?\e$,1C'\e(B consonant "LETTER WO WAEN")
 203            (?\e$,1C(\e(B consonant "LETTER SO SALA")
 204            (?\e$,1C)\e(B consonant "LETTER SO RUSI")
 205            (?\e$,1C*\e(B consonant "LETTER SO SUA")
 206            (?\e$,1C+\e(B consonant "LETTER HO HIP")
 207            (?\e$,1C,\e(B consonant "LETTER LO CHULA")
 208            (?\e$,1C-\e(B consonant "LETTER O ANG")
 209            (?\e$,1C.\e(B consonant "LETTER HO NOK HUK")
 210            (?\e$,1C/\e(B special "PAI YAN NOI (abbreviation)")
 211            (?\e$,1C0\e(B vowel-base "VOWEL SIGN SARA A")
 212            (?\e$,1C1\e(B vowel-upper "VOWEL SIGN MAI HAN-AKAT N/S-T")
 213            (?\e$,1C2\e(B vowel-base "VOWEL SIGN SARA AA")
 214            (?\e$,1C3\e(B vowel-base "VOWEL SIGN SARA AM")
 215            (?\e$,1C4\e(B vowel-upper "VOWEL SIGN SARA I N/S-T")
 216            (?\e$,1C5\e(B vowel-upper "VOWEL SIGN SARA II N/S-T")
 217            (?\e$,1C6\e(B vowel-upper "VOWEL SIGN SARA UE N/S-T")
 218            (?\e$,1C7\e(B vowel-upper "VOWEL SIGN SARA UEE N/S-T")
 219            (?\e$,1C8\e(B vowel-lower "VOWEL SIGN SARA U N/S-B")
 220            (?\e$,1C9\e(B vowel-lower "VOWEL SIGN SARA UU N/S-B")
 221            (?\e$,1C:\e(B vowel-lower "VOWEL SIGN PHINTHU N/S-B (Pali virama)")
 222            (?\e$,1C?\e(B special "BAHT SIGN (currency symbol)")
 223            (?\e$,1C@\e(B vowel-base "VOWEL SIGN SARA E")
 224            (?\e$,1CA\e(B vowel-base "VOWEL SIGN SARA AE")
 225            (?\e$,1CB\e(B vowel-base "VOWEL SIGN SARA O")
 226            (?\e$,1CC\e(B vowel-base "VOWEL SIGN SARA MAI MUAN")
 227            (?\e$,1CD\e(B vowel-base "VOWEL SIGN SARA MAI MALAI")
 228            (?\e$,1CE\e(B vowel-base "LAK KHANG YAO")
 229            (?\e$,1CF\e(B special "MAI YAMOK (repetion)")
 230            (?\e$,1CG\e(B sign-upper "VOWEL SIGN MAI TAI KHU N/S-T")
 231            (?\e$,1CH\e(B tone "TONE MAI EK N/S-T")
 232            (?\e$,1CI\e(B tone "TONE MAI THO N/S-T")
 233            (?\e$,1CJ\e(B tone "TONE MAI TRI N/S-T")
 234            (?\e$,1CK\e(B tone "TONE MAI CHATTAWA N/S-T")
 235            (?\e$,1CL\e(B sign-upper "THANTHAKHAT N/S-T (cancellation mark)")
 236            (?\e$,1CM\e(B sign-upper "NIKKHAHIT N/S-T (final nasal)")
 237            (?\e$,1CN\e(B sign-upper "YAMAKKAN N/S-T")
 238            (?\e$,1CO\e(B special "FONRMAN")
 239            (?\e$,1CP\e(B special "DIGIT ZERO")
 240            (?\e$,1CQ\e(B special "DIGIT ONE")
 241            (?\e$,1CR\e(B special "DIGIT TWO")
 242            (?\e$,1CS\e(B special "DIGIT THREE")
 243            (?\e$,1CT\e(B special "DIGIT FOUR")
 244            (?\e$,1CU\e(B special "DIGIT FIVE")
 245            (?\e$,1CV\e(B special "DIGIT SIX")
 246            (?\e$,1CW\e(B special "DIGIT SEVEN")
 247            (?\e$,1CX\e(B special "DIGIT EIGHT")
 248            (?\e$,1CY\e(B special "DIGIT NINE")
 249            (?\e$,1CZ\e(B special "ANGKHANKHU (ellipsis)")
 250            (?\e$,1C[\e(B special "KHOMUT (beginning of religious texts)")
 251            ))
 252       elm)
 253   (while l
 254     (setq elm (car l) l (cdr l))
 255     (let ((char (car elm))
 256           (ptype (nth 1 elm)))
 257       (put-char-code-property char 'phonetic-type ptype)
 258       (cond ((eq ptype 'consonant)
 259              (modify-category-entry char ?c thai-category-table)
 260              (global-set-key (vector char) 'thai-self-insert-command))
 261             ((memq ptype '(vowel-upper vowel-lower))
 262              (modify-category-entry char ?v thai-category-table)
 263              (if (or (= char ?\e,TT\e(B) (= char ?\e$,1C4\e(B))
 264                  ;; Give category `I' to "SARA I".
 265                  (modify-category-entry char ?I thai-category-table))
 266              (global-set-key (vector char) 'thai-self-insert-command))
 267             ((eq ptype 'tone)
 268              (modify-category-entry char ?t thai-category-table)
 269              (modify-category-entry char ?u thai-category-table)
 270              (global-set-key (vector char) 'thai-self-insert-command))
 271             ((eq ptype 'sign-upper)
 272              (modify-category-entry char ?u thai-category-table)
 273              (if (or (= char ?\e,Tl\e(B) (= char ?\e$,1CL\e(B))
 274                  ;; Give category `U' to "THANTHAKHAT".
 275                  (modify-category-entry char ?U thai-category-table))
 276              (global-set-key (vector char) 'thai-self-insert-command)))
 277       (put-char-code-property char 'name (nth 2 elm)))))
 278
 279 (defun thai-compose-syllable (beg end &optional category-set string)
 280   (or category-set
 281       (setq category-set
 282             (char-category-set (if string (aref string beg) (char-after beg)))))
 283   (if (aref category-set ?c)
 284       ;; Starting with a consonant.  We do relative composition.
 285       (if string
 286           (compose-string string beg end)
 287         (compose-region beg end))
 288     ;; Vowel tone sequence.
 289     (if string
 290         (compose-string string beg end (list (aref string beg) '(Bc . Bc)
 291                                              (aref string (1+ beg))))
 292       (compose-region beg end (list (char-after beg) '(Bc . Bc)
 293                                     (char-after (1+ beg))))))
 294   (- end beg))
 295
 296 ;;;###autoload
 297 (defun thai-compose-region (beg end)
 298   "Compose Thai characters in the region.
 299 When called from a program, expects two arguments,
 300 positions (integers or markers) specifying the region."
 301   (interactive "r")
 302   (let ((pos (point)))
 303     (save-restriction
 304       (narrow-to-region beg end)
 305       (goto-char (point-min))
 306       (with-category-table thai-category-table
 307         (while (re-search-forward thai-composition-pattern nil t)
 308           (setq beg (match-beginning 0) end (match-end 0))
 309           (if (and (> pos beg) (< pos end))
 310               (setq pos end))
 311           (thai-compose-syllable beg end
 312                                  (char-category-set (char-after beg))))))
 313     (goto-char pos)))
 314
 315 ;;;###autoload
 316 (defun thai-compose-string (string)
 317   "Compose Thai characters in STRING and return the resulting string."
 318   (with-category-table thai-category-table
 319     (let ((idx 0))
 320       (while (setq idx (string-match thai-composition-pattern string idx))
 321         (thai-compose-syllable idx (match-end 0) nil string)
 322         (setq idx (match-end 0)))))
 323   string)
 324
 325 ;;;###autoload
 326 (defun thai-compose-buffer ()
 327   "Compose Thai characters in the current buffer."
 328   (interactive)
 329   (thai-compose-region (point-min) (point-max)))
 330
 331 ;;;###autoload
 332 (defun thai-post-read-conversion (len)
 333   (thai-compose-region (point) (+ (point) len))
 334   len)
 335
 336 ;;;###autoload
 337 (defun thai-composition-function (from to pattern &optional string)
 338   "Compose Thai text in the region FROM and TO.
 339 The text matches the regular expression PATTERN.
 340 Optional 4th argument STRING, if non-nil, is a string containing text
 341 to compose.
 342
 343 The return value is number of composed characters."
 344   (when (and (not thai-auto-composition-mode)
 345              (< (1+ from) to))
 346     (with-category-table thai-category-table
 347       (if string
 348           (if (eq (string-match thai-composition-pattern string from) from)
 349               (thai-compose-syllable from (match-end 0) nil string))
 350         (if (save-excursion
 351               (goto-char from)
 352               (and (looking-at thai-composition-pattern)
 353                    (setq to (match-end 0))))
 354             (thai-compose-syllable from to))))))
 355
 356 (defun thai-auto-composition (beg end len)
 357   (with-category-table thai-category-table
 358     (let (category-set)
 359       (while (and (> beg (point-min))
 360                   (setq category-set (char-category-set (char-after (1- beg))))
 361                   (or (aref category-set ?v) (aref category-set ?u)))
 362           (setq beg (1- beg)))
 363       (if (and (> beg (point-min))
 364                (aref (char-category-set (char-after (1- beg))) ?c))
 365           (setq beg (1- beg)))
 366       (while (and (< end (point-max))
 367                   (setq category-set (char-category-set (char-after end)))
 368                   (or (aref category-set ?v) (aref category-set ?u)))
 369         (setq end (1+ end)))
 370       (if (< beg end)
 371           (thai-compose-region beg end)))))
 372
 373 (put 'thai-auto-composition-mode 'permanent-local t)
 374
 375 ;;;###autoload
 376 (define-minor-mode thai-auto-composition-mode
 377   "Minor mode for automatically correct Thai character composition."
 378   :group 'mule
 379   (cond ((null thai-auto-composition-mode)
 380          (remove-hook 'after-change-functions 'thai-auto-composition))
 381         (t
 382          (add-hook 'after-change-functions 'thai-auto-composition))))
 383
 384 ;; Thai-word-mode requires functions in the feature `thai-word'.
 385 (require 'thai-word)
 386
 387 (defvar thai-word-mode-map
 388   (let ((map (make-sparse-keymap)))
 389     (define-key map [remap forward-word] 'thai-forward-word)
 390     (define-key map [remap backward-word] 'thai-backward-word)
 391     (define-key map [remap kill-word] 'thai-kill-word)
 392     (define-key map [remap backward-kill-word] 'thai-backward-kill-word)
 393     (define-key map [remap transpose-words] 'thai-transpose-words)
 394     map)
 395   "Keymap for `thai-word-mode'.")
 396
 397 (define-minor-mode thai-word-mode
 398   "Minor mode to make word-oriented commands aware of Thai words.
 399 The commands affected are \\[forward-word], \\[backward-word], \\[kill-word], \\[backward-kill-word], \\[transpose-words], and \\[fill-paragraph]."
 400   :global t :group 'mule
 401   (cond (thai-word-mode
 402          ;; This enables linebreak between Thai characters.
 403          (modify-category-entry (make-char 'thai-tis620) ?|)
 404          ;; This enables linebreak at a Thai word boundary.
 405          (put-charset-property 'thai-tis620 'fill-find-break-point-function
 406                                'thai-fill-find-break-point))
 407         (t
 408          (modify-category-entry (make-char 'thai-tis620) ?| nil t)
 409          (put-charset-property 'thai-tis620 'fill-find-break-point-function
 410                                nil))))
 411
 412 ;; Function to call on entering the Thai language environment.
 413 (defun setup-thai-language-environment-internal ()
 414   (thai-word-mode 1))
 415
 416 ;; Function to call on exiting the Thai language environment.
 417 (defun exit-thai-language-environment-internal ()
 418   (thai-word-mode -1))
 419
 420 ;;
 421 (provide 'thai-util)
 422
 423 ;;; arch-tag: 59425d6a-8cf9-4e06-a6ab-8ab7dc7a7a97
 424 ;;; thai-util.el ends here