lisp/language/mlm-util.el

   1 ;;; mlm-util.el --- support for composing malayalam characters  -*-coding: iso-2022-7bit;-*-
   2
   3 ;; Copyright (C) 2003, 2004, 2005, 2006, 2007  Free Software Foundation, Inc.
   4
   5 ;; Maintainer:  KAWABATA, Taichi <kawabata@m17n.org>
   6 ;; Keywords: multilingual, Malayalam
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 3, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  23 ;; Boston, MA 02110-1301, USA.
  24
  25 ;; Created: Feb. 11. 2003
  26
  27 ;;; Commentary:
  28
  29 ;; This file provides character(Unicode) to glyph(CDAC) conversion and
  30 ;; composition of Malayalam script characters.
  31
  32 ;;; Code:
  33
  34 ;; Malayalam Composable Pattern
  35 ;;    C .. Consonants
  36 ;;    V .. Vowel
  37 ;;    H .. Halant
  38 ;;    M .. Matra
  39 ;;    V .. Vowel
  40 ;;    A .. Anuswar
  41 ;;    D .. Chandrabindu
  42 ;;    (N .. Zerowidth Non Joiner)
  43 ;;    (J .. Zerowidth Joiner.  )
  44 ;; 1. vowel
  45 ;;  V(A|visargam)?
  46 ;; 2. syllable : maximum of 5 consecutive consonants.  (e.g. kartsnya)
  47 ;;  ((CH)?(CH)?(CH)?CH)?C(H|M?(A|D)?)?
  48
  49 (defconst malayalam-consonant
  50   "[\e$,1@5\e(B-\e$,1@Y\e(B]")
  51
  52 (defconst malayalam-composable-pattern
  53   (concat
  54    "\\([\e$,1@%\e(B-\e$,1@4\e(B][\e$,1@"\e(B]?\\)\\|\e$,1@#\e(B"
  55    "\\|\\("
  56    "\\(?:\\(?:[\e$,1@5\e(B-\e$,1@Y\e(B]\e$,1@m\e(B\\)?\\(?:[\e$,1@5\e(B-\e$,1@Y\e(B]\e$,1@m\e(B\\)?\\(?:[\e$,1@5\e(B-\e$,1@Y\e(B]\e$,1@m\e(B\\)?[\e$,1@5\e(B-\e$,1@Y\e(B]\e$,1@m\e(B\\)?"
  57    "[\e$,1@5\e(B-\e$,1@Y\e(B]\\(?:\e$,1@m\e(B\\|[\e$,1@^\e(B-\e$,1@c@f@g@h@j@j@k@l\e(B]?[\e$,1@"@m\e(B]?\\)?"
  58    "\\)")
  59   "Regexp matching a composable sequence of Malayalam characters.")
  60
  61 ;;;###autoload
  62 (defun malayalam-compose-region (from to)
  63   (interactive "r")
  64   (save-excursion
  65     (save-restriction
  66       (narrow-to-region from to)
  67       (goto-char (point-min))
  68       (while (re-search-forward malayalam-composable-pattern nil t)
  69         (malayalam-compose-syllable-region (match-beginning 0)
  70                                             (match-end 0))))))
  71 (defun malayalam-compose-string (string)
  72   (with-temp-buffer
  73     (insert (decompose-string string))
  74     (malayalam-compose-region (point-min) (point-max))
  75     (buffer-string)))
  76
  77 ;;;###autoload
  78 (defun malayalam-post-read-conversion (len)
  79   (save-excursion
  80     (save-restriction
  81       (let ((buffer-modified-p (buffer-modified-p)))
  82         (narrow-to-region (point) (+ (point) len))
  83         (malayalam-compose-region (point-min) (point-max))
  84         (set-buffer-modified-p buffer-modified-p)
  85         (- (point-max) (point-min))))))
  86
  87 (defun malayalam-range (from to)
  88   "Make the list of the integers of range FROM to TO."
  89   (let (result)
  90     (while (<= from to) (setq result (cons to result) to (1- to))) result))
  91
  92 (defun malayalam-regexp-of-hashtbl-keys (hashtbl)
  93   "Return a regular expression that matches all keys in hashtable HASHTBL."
  94   (let ((max-specpdl-size 1000))
  95     (regexp-opt
  96      (sort
  97       (let (dummy)
  98         (maphash (function (lambda (key val) (setq dummy (cons key dummy)))) hashtbl)
  99         dummy)
 100       (function (lambda (x y) (> (length x) (length y))))))))
 101
 102
 103 ;;;###autoload
 104 (defun malayalam-composition-function (from to pattern  &optional string)
 105   "Compose Malayalam characters in REGION, or STRING if specified.
 106 Assume that the REGION or STRING must fully match the composable
 107 PATTERN regexp."
 108   (if string (malayalam-compose-syllable-string string)
 109     (malayalam-compose-syllable-region from to))
 110   (- to from))
 111
 112 ;; Register a function to compose Malayalam characters.
 113 (mapc
 114  (function (lambda (ucs)
 115    (aset composition-function-table (decode-char 'ucs ucs)
 116          (list (cons malayalam-composable-pattern
 117                      'malayalam-composition-function)))))
 118  (nconc '(#x0d02 #x0d03) (malayalam-range #x0d05 #x0d39)))
 119
 120 ;; Notes on conversion steps.
 121
 122 ;; 1. chars to glyphs
 123 ;;
 124 ;; Simple replacement of characters to glyphs is done.
 125
 126 ;; 2. glyphs reordering.
 127 ;;
 128 ;; Two special reordering rule takes place.
 129 ;; a. following "\e$,46[\e(B" goes to the front.
 130 ;; b. following "\e$,46S6S\e(B", "\e$,46S\e(B" or "\e$,46T\e(B" goes to the front.
 131 ;; This reordering occurs only to the last cluster of consonants.
 132 ;; Preceding consonants with halant characters are not affected.
 133
 134 ;; 3. Composition.
 135 ;;
 136 ;; left modifiers will be attached at the left.
 137 ;; others will be attached right.
 138
 139 (defvar mlm-char-glyph
 140   '(;; various signs
 141     ("\e$,1@"\e(B" . "\e$,46W\e(B")
 142     ("\e$,1@#\e(B" . "\e$,46X\e(B")
 143     ;; Independent Vowels
 144     ("\e$,1@%\e(B" . "\e$,46!\e(B")
 145     ("\e$,1@&\e(B" . "\e$,46"\e(B")
 146     ("\e$,1@'\e(B" . "\e$,46#\e(B")
 147     ("\e$,1@(\e(B" . "\e$,46#6U\e(B")
 148     ("\e$,1@)\e(B" . "\e$,46$\e(B")
 149     ("\e$,1@*\e(B" . "\e$,46$6U\e(B")
 150     ("\e$,1@+\e(B" . "\e$,46%\e(B")
 151     ("\e$,1@,\e(B" . "nil") ;; not in present use, not supported.
 152     ("\e$,1@.\e(B" . "\e$,46&\e(B")
 153     ("\e$,1@/\e(B" . "\e$,46'\e(B")
 154     ("\e$,1@0\e(B" . "\e$,46S6&\e(B")
 155     ("\e$,1@2\e(B" . "\e$,46(\e(B")
 156     ("\e$,1@3\e(B" . "\e$,46(6M\e(B")
 157     ("\e$,1@4\e(B" . "\e$,46(6U\e(B")
 158     ;; Consonants
 159     ("\e$,1@5\e(B" . "\e$,46)\e(B")
 160     ("\e$,1@5@m@5\e(B" . "\e$,47!\e(B")
 161     ("\e$,1@5@m@S\e(B" . "\e$,47"\e(B")
 162     ("\e$,1@5@m@W\e(B" . "\e$,47#\e(B")
 163     ("\e$,1@5@m@?\e(B" . "\e$,47N\e(B")
 164     ("\e$,1@5@m@D\e(B" . "\e$,47`\e(B")
 165     ("\e$,1@5@a\e(B" . "\e$,47f\e(B")
 166     ("\e$,1@5@m@5@a\e(B" . "\e$,47g\e(B")
 167     ("\e$,1@5@a\e(B" . "\e$,47f\e(B")
 168     ("\e$,1@5@m@5@a\e(B" . "\e$,47g\e(B")
 169
 170     ("\e$,1@6\e(B" . "\e$,46*\e(B")
 171
 172     ("\e$,1@7\e(B" . "\e$,46+\e(B")
 173     ("\e$,1@7@m@7\e(B" . "\e$,47$\e(B")
 174     ("\e$,1@7@m@R\e(B" . "\e$,47%\e(B")
 175     ("\e$,1@7@m@N\e(B" . "\e$,47\\e(B")
 176     ("\e$,1@7@m@H\e(B" . "\e$,47a\e(B")
 177
 178     ("\e$,1@8\e(B" . "\e$,46,\e(B")
 179
 180     ("\e$,1@9\e(B" . "\e$,46-\e(B")
 181     ("\e$,1@9@m@5\e(B" . "\e$,47&\e(B")
 182     ("\e$,1@9@m@9\e(B" . "\e$,47'\e(B")
 183     ("\e$,1@9@m@5@a\e(B" . "\e$,47h\e(B")
 184
 185     ("\e$,1@:\e(B" . "\e$,46.\e(B")
 186     ("\e$,1@:@m@:\e(B" . "\e$,47(\e(B") ;; duplicate
 187     ("\e$,1@:@m@;\e(B" . "\e$,47Q\e(B")
 188
 189     ("\e$,1@;\e(B" . "\e$,46/\e(B")
 190
 191     ("\e$,1@<\e(B" . "\e$,460\e(B")
 192     ("\e$,1@<@m@<\e(B" . "\e$,47V\e(B")
 193     ("\e$,1@<@m@>\e(B" . "\e$,47Z\e(B")
 194
 195     ("\e$,1@=\e(B" . "\e$,461\e(B")
 196
 197     ("\e$,1@>\e(B" . "\e$,462\e(B")
 198     ("\e$,1@>@m@:\e(B" . "\e$,47)\e(B")
 199     ("\e$,1@>@m@>\e(B" . "\e$,47*\e(B")
 200
 201     ("\e$,1@?\e(B" . "\e$,463\e(B")
 202     ("\e$,1@?@m@?\e(B" . "\e$,47+\e(B")
 203
 204     ("\e$,1@@\e(B" . "\e$,464\e(B")
 205     ("\e$,1@A\e(B" . "\e$,465\e(B")
 206     ("\e$,1@A@m@A\e(B" . "\e$,47M\e(B")
 207     ("\e$,1@B\e(B" . "\e$,466\e(B")
 208
 209     ("\e$,1@C\e(B" . "\e$,467\e(B")
 210     ("\e$,1@C@a@m\e(B" . "\e$,47,\e(B") ;; half consonant
 211     ("\e$,1@C@m@?\e(B" . "\e$,47-\e(B")
 212     ("\e$,1@C@m@C\e(B" . "\e$,47.\e(B")
 213     ("\e$,1@C@m@N\e(B" . "\e$,47W\e(B")
 214     ("\e$,1@C@m@A\e(B" . "\e$,47^\e(B")
 215     ("\e$,1@C@a\e(B" . "\e$,47i\e(B")
 216
 217     ("\e$,1@D\e(B" . "\e$,468\e(B")
 218     ("\e$,1@D@m@D\e(B" . "\e$,47/\e(B")
 219     ("\e$,1@D@m@E\e(B" . "\e$,470\e(B")
 220     ("\e$,1@D@m@X\e(B" . "\e$,47U\e(B")
 221     ("\e$,1@D@m@M\e(B" . "\e$,47[\e(B")
 222     ("\e$,1@D@m@N\e(B" . "\e$,47_\e(B")
 223
 224     ("\e$,1@E\e(B" . "\e$,469\e(B")
 225
 226     ("\e$,1@F\e(B" . "\e$,46:\e(B")
 227     ("\e$,1@F@m@F\e(B" . "\e$,471\e(B")
 228     ("\e$,1@F@m@G\e(B" . "\e$,472\e(B")
 229
 230     ("\e$,1@G\e(B" . "\e$,46;\e(B")
 231
 232     ("\e$,1@H\e(B" . "\e$,46<\e(B")
 233     ("\e$,1@H@a@m\e(B" . "\e$,473\e(B") ;; half consonant
 234     ("\e$,1@H@m@D\e(B" . "\e$,474\e(B")
 235     ("\e$,1@H@m@F\e(B" . "\e$,475\e(B")
 236     ("\e$,1@H@m@H\e(B" . "\e$,476\e(B")
 237     ("\e$,1@H@m@N\e(B" . "\e$,477\e(B")
 238     ("\e$,1@H@m@G\e(B" . "\e$,47T\e(B")
 239     ("\e$,1@H@m@E\e(B" . "\e$,47Y\e(B")
 240     ("\e$,1@H@m@Q\e(B" . "\e$,47b\e(B")
 241     ("\e$,1@H@a\e(B" . "\e$,47k\e(B")
 242     ("\e$,1@H@m@H@a\e(B" . "\e$,47l\e(B")
 243
 244     ("\e$,1@J\e(B" . "\e$,46=\e(B")
 245     ("\e$,1@J@m@J\e(B" . "\e$,478\e(B") ;; duplicate
 246     ("\e$,1@J@m@R\e(B" . "\e$,479\e(B") ;; lakar
 247
 248     ("\e$,1@K\e(B" . "\e$,46>\e(B")
 249
 250     ("\e$,1@L\e(B" . "\e$,46?\e(B")
 251     ("\e$,1@L@m@L\e(B" . "\e$,47:\e(B") ;; duplicate
 252     ("\e$,1@L@m@R\e(B" . "\e$,47;\e(B") ;; lakar
 253     ("\e$,1@L@m@G\e(B" . "\e$,47O\e(B")
 254     ("\e$,1@L@m@F\e(B" . "\e$,47P\e(B")
 255
 256     ("\e$,1@M\e(B" . "\e$,46@\e(B")
 257
 258     ("\e$,1@N\e(B" . "\e$,46A\e(B")
 259     ("\e$,1@N@m@J\e(B" . "\e$,47<\e(B")
 260     ("\e$,1@N@m@N\e(B" . "\e$,47=\e(B")
 261     ("\e$,1@N@m@R\e(B" . "\e$,47>\e(B") ;; lakar
 262
 263     ("\e$,1@O\e(B" . "\e$,46B\e(B")
 264     ("\e$,1@O@m@O\e(B" . "\e$,47?\e(B") ;; duplicate
 265     ("\e$,1@O@m@5@m@5\e(B" . "\e$,47m\e(B")
 266
 267     ("\e$,1@P\e(B" . "\e$,46C\e(B")
 268     ("\e$,1@P@a@m\e(B" . "\e$,47@\e(B")
 269     ("\e$,1@P@a\e(B" . "\e$,47j\e(B")
 270
 271     ("\e$,1@Q\e(B" . "\e$,46D\e(B")
 272     ("\e$,1@Q@m\e(B" . "\e$,47@\e(B") ;; same glyph as "\e$,1@P@m\e(B"
 273     ("\e$,1@Q@a@m\e(B" . "\e$,47@\e(B") ;; same glyph as "\e$,1@P@m\e(B"
 274     ;;("\e$,1@Q@m@Q\e(B" . "\e$,47A\e(B")
 275     ("\e$,1@Q@m@Q\e(B" . "\e$,47d\e(B")
 276
 277     ("\e$,1@R\e(B" . "\e$,46E\e(B")
 278     ("\e$,1@R@a@m\e(B" . "\e$,47B\e(B")
 279     ("\e$,1@R@m@R\e(B" . "\e$,47C\e(B") ;; lakar
 280     ("\e$,1@R@m@J\e(B" . "\e$,47e\e(B")
 281
 282     ("\e$,1@S\e(B" . "\e$,46F\e(B")
 283     ("\e$,1@S@a@m\e(B" . "\e$,47D\e(B")
 284     ("\e$,1@S@m@S\e(B" . "\e$,47E\e(B")
 285
 286     ("\e$,1@T\e(B" . "\e$,46G\e(B")
 287
 288     ("\e$,1@U\e(B" . "\e$,46H\e(B")
 289     ("\e$,1@U@m@U\e(B" . "\e$,47F\e(B")
 290
 291     ("\e$,1@V\e(B" . "\e$,46I\e(B")
 292     ("\e$,1@V@m@R\e(B" . "\e$,47G\e(B")
 293     ("\e$,1@V@m@V\e(B" . "\e$,47H\e(B")
 294     ("\e$,1@V@m@:\e(B" . "\e$,47]\e(B")
 295
 296     ("\e$,1@W\e(B" . "\e$,46J\e(B")
 297     ("\e$,1@W@m@?\e(B" . "\e$,47c\e(B")
 298
 299     ("\e$,1@X\e(B" . "\e$,46K\e(B")
 300     ("\e$,1@X@m@R\e(B" . "\e$,47I\e(B")
 301     ("\e$,1@X@m@X\e(B" . "\e$,47J\e(B")
 302     ("\e$,1@X@m@Q@m@Q\e(B" . "\e$,47L\e(B")
 303     ("\e$,1@X@m@E\e(B" . "\e$,47X\e(B")
 304
 305     ("\e$,1@Y\e(B" . "\e$,46L\e(B")
 306     ("\e$,1@Y@m@R\e(B" . "\e$,47K\e(B")
 307     ("\e$,1@Y@m@N\e(B" . "\e$,47R\e(B")
 308     ("\e$,1@Y@m@H\e(B" . "\e$,47S\e(B")
 309
 310     ;; Dependent vowel signs
 311     ("\e$,1@^\e(B" . "\e$,46M\e(B")
 312     ("\e$,1@_\e(B" . "\e$,46N\e(B")
 313     ("\e$,1@`\e(B" . "\e$,46O\e(B")
 314     ("\e$,1@a\e(B" . "\e$,46P\e(B")
 315     ("\e$,1@b\e(B" . "\e$,46Q\e(B")
 316     ("\e$,1@c\e(B" . "\e$,46R\e(B")
 317     ("\e$,1@f\e(B" . "\e$,46S\e(B")
 318     ("\e$,1@g\e(B" . "\e$,46T\e(B")
 319     ("\e$,1@h\e(B" . "\e$,46S6S\e(B")
 320     ("\e$,1@j\e(B" . "\e$,46S6M\e(B")
 321     ("\e$,1@k\e(B" . "\e$,46T6M\e(B")
 322     ("\e$,1@l\e(B" . "\e$,46U\e(B")
 323     ;; Various signs
 324     ("\e$,1@m\e(B" . "\e$,46V\e(B")
 325     ("\e$,1@m@O\e(B" . "\e$,46Y\e(B") ;; yakar
 326     ("\e$,1@m@O@a\e(B" . "\e$,46\\e(B") ;; yakar + u
 327     ("\e$,1@m@O@b\e(B" . "\e$,46]\e(B") ;; yakar + uu
 328     ("\e$,1@m@U\e(B" . "\e$,46Z\e(B") ;; vakar modifier
 329     ("\e$,1@m@P\e(B" . "\e$,46[\e(B") ;; rakar modifier is the same to rra modifier.
 330     ("\e$,1@m@P@m\e(B" . "\e$,46R\e(B") ;; halant + rakar + halant
 331     ("\e$,1@m@Q\e(B" . "\e$,46[\e(B") ;; rrakar modifier
 332     ("\e$,1@m@Q@m\e(B" . "\e$,46R\e(B") ;; halant + rrakar + halant
 333     ("\e$,1@m@m\e(B" . "\e$,46V\e(B") ;; double omission sign to stop forming half consonant.
 334     ("\e$,1@w\e(B" . "\e$,46U\e(B") ;; not in present use, already at 0D4C.
 335     ))
 336
 337 (defvar mlm-char-glyph-hash
 338   (let* ((hash (make-hash-table :test 'equal)))
 339     (mapc (function (lambda (x) (puthash (car x) (cdr x) hash)))
 340           mlm-char-glyph)
 341     hash))
 342
 343 (defvar mlm-char-glyph-regexp
 344   (malayalam-regexp-of-hashtbl-keys mlm-char-glyph-hash))
 345
 346 ;; Malayalam languages needed to be reordered in a complex mannar.
 347
 348 (defvar mlm-consonants
 349   (concat
 350   "\e$,46)6*6+6,6-6.6/606162636465666768696:6;6<6=6>6?6@6A6B6C6D6E6F6G6H6I6J6K6L\e(B"
 351   "\e$,47!7"7#7$7%7&7'7(7)7*7+7,7-7.7/707172737475767778797:7;7<7=7>7?7@7A7B7C7D7E7F7G7H7I7J7K7L7M7N7O7P7Q7R7S7T7U7V7W7X7Y7Z7[7\7]7^7_7`7a7b7c7d7e\e(B"
 352   ))
 353
 354 (defvar mlm-consonants-regexp
 355   (concat "\\(\e$,46[\e(B?[" mlm-consonants "][\e$,46Y6Z\e(B]?\\)"))
 356
 357 (defvar mlm-glyph-reorder-key-glyphs "[\e$,46[6S6T\e(B]")
 358
 359 (defvar mlm-glyph-reordering-regexp-list
 360   `((,(concat "\\([" mlm-consonants "][\e$,46Y6Z\e(B]?\\)\e$,46[\e(B") . "\e$,46[\e(B\\1")
 361     (,(concat mlm-consonants-regexp "\e$,46S6S\e(B") . "\e$,46S6S\e(B\\1")
 362     (,(concat mlm-consonants-regexp "\e$,46S\e(B") . "\e$,46S\e(B\\1")
 363     (,(concat mlm-consonants-regexp "\e$,46T\e(B") . "\e$,46T\e(B\\1")))
 364
 365 (defun malayalam-compose-syllable-string (string)
 366   (with-temp-buffer
 367     (insert (decompose-string string))
 368     (malayalam-compose-syllable-region (point-min) (point-max))
 369     (buffer-string)))
 370
 371 (defun malayalam-compose-syllable-region (from to)
 372   "Compose malayalam syllable in region FROM to TO."
 373   (let (glyph-str
 374         match-str
 375         glyph-reorder-regexps
 376         glyph-reorder-replace
 377         glyph-reorder-regexp)
 378     (save-excursion
 379       (save-restriction
 380         (narrow-to-region from to)
 381         (goto-char (point-min))
 382         ;; char-glyph-conversion
 383         (while (re-search-forward mlm-char-glyph-regexp nil t)
 384           (setq match-str (match-string 0))
 385           (setq glyph-str
 386                 (concat glyph-str (gethash match-str mlm-char-glyph-hash))))
 387         (when (string-match mlm-glyph-reorder-key-glyphs glyph-str)
 388           ;; glyph reordering
 389           (setq glyph-reorder-regexps mlm-glyph-reordering-regexp-list)
 390           (while glyph-reorder-regexps
 391             (setq glyph-reorder-regexp (caar glyph-reorder-regexps))
 392             (setq glyph-reorder-replace (cdar glyph-reorder-regexps))
 393             (setq glyph-reorder-regexps (cdr glyph-reorder-regexps))
 394             (if (string-match glyph-reorder-regexp glyph-str)
 395                 (setq glyph-str
 396                       (replace-match glyph-reorder-replace nil nil
 397                                      glyph-str)))))
 398         ;; concatenate and attach reference-points.
 399         (setq glyph-str
 400               (cdr
 401                (apply
 402                 'nconc
 403                 (mapcar
 404                  (function
 405                   (lambda (x) (list '(5 . 3) x))) ;; default ref. point.
 406                  glyph-str))))
 407         (compose-region from to glyph-str)))))
 408
 409 (provide 'mlm-util)
 410
 411 ;;; arch-tag: 7f25ee67-8f9d-49f2-837b-35c412c00eba
 412 ;;; devan-util.el ends here