lisp/language/tibet-util.el

   1 ;;; tibet-util.el --- utilities for Tibetan   -*- coding: iso-2022-7bit; -*-
   2
   3 ;; Copyright (C) 1997, 2002  Free Software Foundation, Inc.
   4 ;; Copyright (C) 1995, 1997, 1998, 2000
   5 ;;   National Institute of Advanced Industrial Science and Technology (AIST)
   6 ;;   Registration Number H14PRO021
   7
   8 ;; Keywords: multilingual, Tibetan
   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 ;; Author: Toru TOMABECHI, <Toru.Tomabechi@orient.unil.ch>
  28
  29 ;; Created: Feb. 17. 1997
  30
  31 ;;; History:
  32 ;; 1997.03.13 Modification in treatment of text properties;
  33 ;;            Support for some special signs and punctuations.
  34 ;; 1999.10.25 Modification for a new composition way by K.Handa.
  35
  36 ;;; Commentary:
  37
  38 ;;; Code:
  39
  40 (defconst tibetan-obsolete-glyphs
  41   `(("\e$(7!=\e(B" . "\e$(8!=\e(B")                 ; 2 col <-> 1 col
  42     ("\e$(7!?\e(B" . "\e$(8!?\e(B")
  43     ("\e$(7!@\e(B" . "\e$(8!@\e(B")
  44     ("\e$(7!A\e(B" . "\e$(8!A\e(B")
  45     ("\e$(7"`\e(B" . "\e$(8"`\e(B")
  46     ("\e$(7!;\e(B" . "\e$(8!;\e(B")
  47     ("\e$(7!D\e(B" . "\e$(8!D\e(B")
  48     ;; Yes these are dirty. But ...
  49     ("\e$(7!>\e(B \e$(7!>\e(B" . ,(compose-string "\e$(7!>\e(B \e$(7!>\e(B" 0 3 [?\e$(7!>\e(B (Br . Bl) ?  (Br . Bl) ?\e$(7!>\e(B]))
  50     ("\e$(7!4!5!5\e(B" . ,(compose-string
  51                   "\e$(7#R#S#S#S\e(B" 0 4
  52                   [?\e$(7#R\e(B (Br . Bl) ?\e$(7#S\e(B (Br . Bl) ?\e$(7#S\e(B (Br . Bl) ?\e$(7#S\e(B]))
  53     ("\e$(7!4!5\e(B" . ,(compose-string "\e$(7#R#S#S\e(B" 0 3 [?\e$(7#R\e(B (Br . Bl) ?\e$(7#S\e(B (Br . Bl) ?\e$(7#S\e(B]))
  54     ("\e$(7!6\e(B" . ,(compose-string "\e$(7#R#S!I\e(B" 0 3 [?\e$(7#R\e(B (Br . Bl) ?\e$(7#S\e(B (br . tr) ?\e$(7!I\e(B]))
  55     ("\e$(7!4\e(B"   . ,(compose-string "\e$(7#R#S\e(B" 0 2 [?\e$(7#R\e(B (Br . Bl) ?\e$(7#S\e(B]))))
  56
  57 ;;;###autoload
  58 (defun tibetan-char-p (ch)
  59   "Check if char CH is Tibetan character.
  60 Returns non-nil if CH is Tibetan. Otherwise, returns nil."
  61   (memq (char-charset ch) '(tibetan tibetan-1-column)))
  62
  63 ;;; Functions for Tibetan <-> Tibetan-transcription.
  64
  65 ;;;###autoload
  66 (defun tibetan-tibetan-to-transcription (str)
  67   "Transcribe Tibetan string STR and return the corresponding Roman string."
  68   (let (;; Accumulate transcriptions here in reverse order.
  69         (trans nil)
  70         (len (length str))
  71         (i 0)
  72         ch this-trans)
  73     (while (< i len)
  74       (let ((idx (string-match tibetan-precomposition-rule-regexp str i)))
  75         (if (eq idx i)
  76             ;; Ith character and the followings matches precomposable
  77             ;; Tibetan sequence.
  78             (setq i (match-end 0)
  79                   this-trans
  80                   (car (rassoc
  81                         (cdr (assoc (match-string 0 str)
  82                                     tibetan-precomposition-rule-alist))
  83                         tibetan-precomposed-transcription-alist)))
  84           (setq ch (substring str i (1+ i))
  85                 i (1+ i)
  86                 this-trans
  87                 (car (or (rassoc ch tibetan-consonant-transcription-alist)
  88                          (rassoc ch tibetan-vowel-transcription-alist)
  89                          (rassoc ch tibetan-subjoined-transcription-alist)))))
  90         (setq trans (cons this-trans trans))))
  91     (apply 'concat (nreverse trans))))
  92
  93 ;;;###autoload
  94 (defun tibetan-transcription-to-tibetan (str)
  95   "Convert Tibetan Roman string STR to Tibetan character string.
  96 The returned string has no composition information."
  97   (let (;; Case is significant.
  98         (case-fold-search nil)
  99         (idx 0)
 100         ;; Accumulate Tibetan strings here in reverse order.
 101         (t-str-list nil)
 102         i subtrans)
 103     (while (setq i (string-match tibetan-regexp str idx))
 104       (if (< idx i)
 105           ;; STR contains a pattern that doesn't match Tibetan
 106           ;; transcription.  Include the pattern as is.
 107           (setq t-str-list (cons (substring str idx i) t-str-list)))
 108       (setq subtrans (match-string 0 str)
 109             idx (match-end 0))
 110       (let ((t-char (cdr (assoc subtrans
 111                                 tibetan-precomposed-transcription-alist))))
 112         (if t-char
 113             ;; SUBTRANS corresponds to a transcription for
 114             ;; precomposable Tibetan sequence.
 115             (setq t-char (car (rassoc t-char
 116                                       tibetan-precomposition-rule-alist)))
 117           (setq t-char
 118                 (cdr
 119                  (or (assoc subtrans tibetan-consonant-transcription-alist)
 120                      (assoc subtrans tibetan-vowel-transcription-alist)
 121                      (assoc subtrans tibetan-modifier-transcription-alist)
 122                      (assoc subtrans tibetan-subjoined-transcription-alist)))))
 123         (setq t-str-list (cons t-char t-str-list))))
 124     (if (< idx (length str))
 125         (setq t-str-list (cons (substring str idx) t-str-list)))
 126     (apply 'concat (nreverse t-str-list))))
 127
 128 ;;;
 129 ;;; Functions for composing/decomposing Tibetan sequence.
 130 ;;;
 131 ;;; A Tibetan syllable is typically structured as follows:
 132 ;;;
 133 ;;;      [Prefix] C [C+] V [M] [Suffix [Post suffix]]
 134 ;;;
 135 ;;; where C's are all vertically stacked, V appears below or above
 136 ;;; consonant cluster and M is always put above the C[C+]V combination.
 137 ;;; (Sanskrit visarga, though it is a vowel modifier, is considered
 138 ;;;  to be a punctuation.)
 139 ;;;
 140 ;;; Here are examples of the words "bsgrubs" and "hfauM"
 141 ;;;
 142 ;;;            \e4\e$(7"7\e0"7\e1\e4%qx!"U\e0"G###C"U\e1\e4"7\e0"7\e1\e4"G\e0"G\e1\e(B            \e4\e$(7"Hx!"Rx!"Ur'"_\e0"H"R"U"_\e1\e(B
 143 ;;;
 144 ;;;                             M
 145 ;;;             b s b s         h
 146 ;;;               g             fa
 147 ;;;               r             u
 148 ;;;               u
 149 ;;;
 150 ;;; Consonants `'' (\e$(7"A\e(B), `w' (\e$(7">\e(B), `y' (\e$(7"B\e(B), `r' (\e$(7"C\e(B) take special
 151 ;;; forms when they are used as subjoined consonant.  Consonant `r'
 152 ;;; takes another special form when used as superjoined in such a case
 153 ;;; as "rka", while it does not change its form when conjoined with
 154 ;;; subjoined `'', `w' or `y' as in "rwa", "rya".
 155
 156 ;; Append a proper composition rule and glyph to COMPONENTS to compose
 157 ;; CHAR with a composition that has COMPONENTS.
 158
 159 (defun tibetan-add-components (components char)
 160   (let ((last (last components))
 161         (stack-upper '(tc . bc))
 162         (stack-under '(bc . tc))
 163         rule comp-vowel tmp)
 164     ;; Special treatment for 'a chung.
 165     ;; If 'a follows a consonant, turn it into the subjoined form.
 166     ;; * Disabled by Tomabechi 2000/06/09 *
 167     ;; Because in Unicode, \e$(7"A\e(B may follow directly a consonant without
 168     ;; any intervening vowel, as in \e4\e$(7"9\e0"9\e1\e4""\e0"""Q\e1\e4"A\e0"A\e1!;\e(B=\e4\e$(7"9\e0"9\e1\e(B \e4\e$(7""\e0""\e1\e(B \e4\e$(7"A\e0"A\e1\e(B not \e4\e$(7"9\e0"9\e1\e(B \e4\e$(7""\e0""\e1\e(B \e$(7"Q\e(B \e4\e$(7"A\e0"A\e1\e(B
 169     ;;(if (and (= char ?\e$(7"A\e(B)
 170     ;;       (aref (char-category-set (car last)) ?0))
 171     ;;  (setq char ?\e$(7"R\e(B)) ;; modified for new font by Tomabechi 1999/12/10
 172
 173     ;; Composite vowel signs are decomposed before being added
 174     ;; Added by Tomabechi 2000/06/08
 175     (if (memq char '(?\e$(7"T\e(B ?\e$(7"V\e(B ?\e$(7"W\e(B ?\e$(7"X\e(B ?\e$(7"Y\e(B ?\e$(7"Z\e(B ?\e$(7"b\e(B))
 176         (setq comp-vowel
 177               (copy-sequence
 178                (cddr (assoc (char-to-string char)
 179                             tibetan-composite-vowel-alist)))
 180               char
 181               (cadr (assoc (char-to-string char)
 182                            tibetan-composite-vowel-alist))))
 183     (cond
 184      ;; Compose upper vowel sign vertically over.
 185      ((aref (char-category-set char) ?2)
 186       (setq rule stack-upper))
 187
 188      ;; Compose lower vowel sign vertically under.
 189      ((aref (char-category-set char) ?3)
 190       (if (eq char ?\e$(7"Q\e(B)          ;; `\e$(7"Q\e(B' should not visible when composed.
 191           (setq rule nil)
 192         (setq rule stack-under)))
 193      ;; Transform ra-mgo (superscribed r) if followed by a subjoined
 194      ;; consonant other than w, ', y, r.
 195      ((and (= (car last) ?\e$(7"C\e(B)
 196            (not (memq char '(?\e$(7#>\e(B ?\e$(7"R\e(B ?\e$(7#B\e(B ?\e$(7#C\e(B))))
 197       (setcar last ?\e$(7!"\e(B) ;; modified for newfont by Tomabechi 1999/12/10
 198       (setq rule stack-under))
 199      ;; Transform initial base consonant if followed by a subjoined
 200      ;; consonant but 'a.
 201      (t
 202       (let ((laststr (char-to-string (car last))))
 203         (if (and (/= char ?\e$(7"R\e(B) ;; modified for new font by Tomabechi
 204                  (string-match "[\e$(7"!\e(B-\e$(7"="?"@"D\e(B-\e$(7"J"K\e(B]" laststr))
 205             (setcar last (string-to-char
 206                           (cdr (assoc (char-to-string (car last))
 207                                       tibetan-base-to-subjoined-alist)))))
 208         (setq rule stack-under))))
 209
 210     (if rule
 211         (setcdr last (list rule char)))
 212     ;; Added by Tomabechi 2000/06/08
 213     (if comp-vowel
 214         (nconc last comp-vowel))
 215     ))
 216
 217 ;;;###autoload
 218 (defun tibetan-compose-string (str)
 219   "Compose Tibetan string STR."
 220   (let ((idx 0))
 221     ;; `\e$(7"A\e(B' is included in the pattern for subjoined consonants
 222     ;; because we treat it specially in tibetan-add-components.
 223     ;; (This feature is removed by Tomabechi 2000/06/08)
 224     (while (setq idx (string-match tibetan-composable-pattern str idx))
 225       (let ((from idx)
 226             (to (match-end 0))
 227             components)
 228         (if (eq (string-match tibetan-precomposition-rule-regexp str idx) idx)
 229             (setq idx (match-end 0)
 230                   components
 231                   (list (string-to-char
 232                          (cdr
 233                           (assoc (match-string 0 str)
 234                                  tibetan-precomposition-rule-alist)))))
 235           (setq components (list (aref str idx))
 236                 idx (1+ idx)))
 237         (while (< idx to)
 238           (tibetan-add-components components (aref str idx))
 239           (setq idx (1+ idx)))
 240         (compose-string str from to components))))
 241   str)
 242
 243 ;;;###autoload
 244 (defun tibetan-compose-region (beg end)
 245   "Compose Tibetan text the region BEG and END."
 246   (interactive "r")
 247   (let (str result chars)
 248     (save-excursion
 249       (save-restriction
 250         (narrow-to-region beg end)
 251         (goto-char (point-min))
 252         ;; `\e$(7"A\e(B' is included in the pattern for subjoined consonants
 253         ;; because we treat it specially in tibetan-add-components.
 254         ;; (This feature is removed by Tomabechi 2000/06/08)
 255         (while (re-search-forward tibetan-composable-pattern nil t)
 256           (let ((from (match-beginning 0))
 257                 (to (match-end 0))
 258                 components)
 259             (goto-char from)
 260             (if (looking-at tibetan-precomposition-rule-regexp)
 261                 (progn
 262                   (setq components
 263                         (list (string-to-char
 264                                (cdr
 265                                 (assoc (match-string 0)
 266                                        tibetan-precomposition-rule-alist)))))
 267                   (goto-char (match-end 0)))
 268               (setq components (list (char-after from)))
 269               (forward-char 1))
 270             (while (< (point) to)
 271               (tibetan-add-components components (following-char))
 272               (forward-char 1))
 273             (compose-region from to components)))))))
 274
 275 (defvar tibetan-decompose-precomposition-alist
 276   (mapcar (function (lambda (x) (cons (string-to-char (cdr x)) (car x))))
 277           tibetan-precomposition-rule-alist))
 278
 279 ;;;###autoload
 280 (defun tibetan-decompose-region (from to)
 281   "Decompose Tibetan text in the region FROM and TO.
 282 This is different from decompose-region because precomposed Tibetan characters
 283 are decomposed into normal Tibetan character sequences."
 284   (interactive "r")
 285   (save-restriction
 286     (narrow-to-region from to)
 287     (decompose-region from to)
 288     (goto-char from)
 289     (while (not (eobp))
 290       (let* ((char (following-char))
 291              (slot (assq char tibetan-decompose-precomposition-alist)))
 292         (if slot
 293             (progn
 294               (delete-char 1)
 295               (insert (cdr slot)))
 296           (forward-char 1))))))
 297
 298
 299 ;;;###autoload
 300 (defun tibetan-decompose-string (str)
 301   "Decompose Tibetan string STR.
 302 This is different from decompose-string because precomposed Tibetan characters
 303 are decomposed into normal Tibetan character sequences."
 304   (let ((new "")
 305         (len (length str))
 306         (idx 0)
 307         char slot)
 308     (while (< idx len)
 309       (setq char (aref str idx)
 310             slot (assq (aref str idx) tibetan-decompose-precomposition-alist)
 311             new (concat new (if slot (cdr slot) (char-to-string char)))
 312             idx (1+ idx)))
 313     new))
 314
 315 ;;;###autoload
 316 (defun tibetan-composition-function (from to pattern &optional string)
 317   (if string
 318       (tibetan-compose-string string)
 319     (tibetan-compose-region from to))
 320   (- to from))
 321
 322 ;;;
 323 ;;; This variable is used to avoid repeated decomposition.
 324 ;;;
 325 (setq-default tibetan-decomposed nil)
 326
 327 ;;;###autoload
 328 (defun tibetan-decompose-buffer ()
 329   "Decomposes Tibetan characters in the buffer into their components.
 330 See also the documentation of the function `tibetan-decompose-region'."
 331   (interactive)
 332   (make-local-variable 'tibetan-decomposed)
 333   (cond ((not tibetan-decomposed)
 334          (tibetan-decompose-region (point-min) (point-max))
 335          (setq tibetan-decomposed t))))
 336
 337 ;;;###autoload
 338 (defun tibetan-compose-buffer ()
 339   "Composes Tibetan character components in the buffer.
 340 See also docstring of the function tibetan-compose-region."
 341   (interactive)
 342   (make-local-variable 'tibetan-decomposed)
 343   (tibetan-compose-region (point-min) (point-max))
 344   (setq tibetan-decomposed nil))
 345
 346 ;;;###autoload
 347 (defun tibetan-post-read-conversion (len)
 348   (save-excursion
 349     (save-restriction
 350       (let ((buffer-modified-p (buffer-modified-p)))
 351         (narrow-to-region (point) (+ (point) len))
 352         (tibetan-compose-region (point-min) (point-max))
 353         (set-buffer-modified-p buffer-modified-p)
 354         (make-local-variable 'tibetan-decomposed)
 355         (setq tibetan-decomposed nil)
 356         (- (point-max) (point-min))))))
 357
 358
 359 ;;;###autoload
 360 (defun tibetan-pre-write-conversion (from to)
 361   (setq tibetan-decomposed-temp tibetan-decomposed)
 362   (let ((old-buf (current-buffer)))
 363     (set-buffer (generate-new-buffer " *temp*"))
 364     (if (stringp from)
 365         (insert from)
 366       (insert-buffer-substring old-buf from to))
 367     (if (not tibetan-decomposed-temp)
 368         (tibetan-decompose-region (point-min) (point-max)))
 369     ;; Should return nil as annotations.
 370     nil))
 371
 372 \f
 373 ;;;
 374 ;;; Unicode-related definitions.
 375 ;;;
 376
 377 (defvar tibetan-canonicalize-for-unicode-alist
 378   '(("\e$(7"Q\e(B" . "")  ;; remove vowel a
 379     ("\e$(7"T\e(B" . "\e$(7"R"S\e(B") ;; decompose vowels whose use is ``discouraged'' in Unicode 3.0
 380     ("\e$(7"V\e(B" . "\e$(7"R"U\e(B")
 381     ("\e$(7"W\e(B" . "\e$(7#C"a\e(B")
 382     ("\e$(7"X\e(B" . "\e$(7#C"R"a\e(B")
 383     ("\e$(7"Y\e(B" . "\e$(7#D"a\e(B")
 384     ("\e$(7"Z\e(B" . "\e$(7#D"R"a\e(B")
 385     ("\e$(7"b\e(B" . "\e$(7"R"a\e(B"))
 386   "Rules for canonicalizing Tibetan vowels for Unicode.")
 387
 388 (defvar tibetan-canonicalize-for-unicode-regexp
 389   "[\e$(7"Q"T"V"W"X"Y"Z"b\e(B]"
 390   "Regexp for Tibetan vowels to be canonicalized in Unicode.")
 391
 392 (defun tibetan-canonicalize-for-unicode-region (from to)
 393   (save-restriction
 394     (narrow-to-region from to)
 395     (goto-char from)
 396     (while (re-search-forward tibetan-canonicalize-for-unicode-regexp nil t)
 397       (let (
 398             ;;(from (match-beginning 0))
 399             ;;(to (match-end 0))
 400             (canonical-form
 401              (cdr (assoc (match-string 0)
 402                          tibetan-canonicalize-for-unicode-alist))))
 403         ;;(goto-char from)
 404         ;;(delete-region from to)
 405         ;;(insert canonical-form)
 406         (replace-match canonical-form)
 407         ))))
 408
 409 (defvar tibetan-strict-unicode t
 410   "*Flag to control Tibetan canonicalizing for Unicode.
 411
 412 If non-nil, the vowel a is removed and composite vowels are decomposed
 413 before writing buffer in Unicode.  See also
 414 `tibetan-canonicalize-for-unicode-regexp' and
 415 `tibetan-canonicalize-for-unicode-alist'.")
 416
 417 ;;;###autoload
 418 (defun tibetan-pre-write-canonicalize-for-unicode (from to)
 419   (let ((old-buf (current-buffer))
 420         (strict-unicode tibetan-strict-unicode))
 421     (set-buffer (generate-new-buffer " *temp*"))
 422     (if (stringp from)
 423         (insert from)
 424       (insert-buffer-substring old-buf from to))
 425     (if strict-unicode
 426         (tibetan-canonicalize-for-unicode-region (point-min) (point-max)))
 427     ;; Should return nil as annotations.
 428     nil))
 429
 430 (provide 'tibet-util)
 431
 432 ;;; arch-tag: 7a7333e8-1584-446c-b39c-a02b9def265d
 433 ;;; tibet-util.el ends here