lisp/language/tibet-util.el

   1 ;;; tibet-util.el --- utilities for Tibetan   -*- coding: iso-2022-7bit; -*-
   2
   3 ;; Copyright (C) 1997, 2001, 2002, 2003, 2004, 2005, 2006
   4 ;;   Free Software Foundation, Inc.
   5 ;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   6 ;;   2005, 2006
   7 ;;   National Institute of Advanced Industrial Science and Technology (AIST)
   8 ;;   Registration Number H14PRO021
   9
  10 ;; Keywords: multilingual, Tibetan
  11
  12 ;; This file is part of GNU Emacs.
  13
  14 ;; GNU Emacs is free software; you can redistribute it and/or modify
  15 ;; it under the terms of the GNU General Public License as published by
  16 ;; the Free Software Foundation; either version 2, or (at your option)
  17 ;; any later version.
  18
  19 ;; GNU Emacs is distributed in the hope that it will be useful,
  20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 ;; GNU General Public License for more details.
  23
  24 ;; You should have received a copy of the GNU General Public License
  25 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  26 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  27 ;; Boston, MA 02110-1301, USA.
  28
  29 ;; Author: Toru TOMABECHI, <Toru.Tomabechi@orient.unil.ch>
  30
  31 ;; Created: Feb. 17. 1997
  32
  33 ;;; History:
  34 ;; 1997.03.13 Modification in treatment of text properties;
  35 ;;            Support for some special signs and punctuations.
  36 ;; 1999.10.25 Modification for a new composition way by K.Handa.
  37
  38 ;;; Commentary:
  39
  40 ;;; Code:
  41
  42 (defconst tibetan-obsolete-glyphs
  43   `(("\e$(7!=\e(B" . "\e$(8!=\e(B")                 ; 2 col <-> 1 col
  44     ("\e$(7!?\e(B" . "\e$(8!?\e(B")
  45     ("\e$(7!@\e(B" . "\e$(8!@\e(B")
  46     ("\e$(7!A\e(B" . "\e$(8!A\e(B")
  47     ("\e$(7"`\e(B" . "\e$(8"`\e(B")
  48     ("\e$(7!;\e(B" . "\e$(8!;\e(B")
  49     ("\e$(7!D\e(B" . "\e$(8!D\e(B")
  50     ;; Yes these are dirty. But ...
  51     ("\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]))
  52     ("\e$(7!4!5!5\e(B" . ,(compose-string
  53                   "\e$(7#R#S#S#S\e(B" 0 4
  54                   [?\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]))
  55     ("\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$(7#S\e(B]))
  56     ("\e$(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]))
  57     ("\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]))))
  58
  59 ;;;###autoload
  60 (defun tibetan-char-p (ch)
  61   "Check if char CH is Tibetan character.
  62 Returns non-nil if CH is Tibetan. Otherwise, returns nil."
  63   (memq (char-charset ch) '(tibetan tibetan-1-column)))
  64
  65 ;;; Functions for Tibetan <-> Tibetan-transcription.
  66
  67 ;;;###autoload
  68 (defun tibetan-tibetan-to-transcription (str)
  69   "Transcribe Tibetan string STR and return the corresponding Roman string."
  70   (let (;; Accumulate transcriptions here in reverse order.
  71         (trans nil)
  72         (len (length str))
  73         (i 0)
  74         ch this-trans)
  75     (while (< i len)
  76       (let ((idx (string-match tibetan-precomposition-rule-regexp str i)))
  77         (if (eq idx i)
  78             ;; Ith character and the followings matches precomposable
  79             ;; Tibetan sequence.
  80             (setq i (match-end 0)
  81                   this-trans
  82                   (car (rassoc
  83                         (cdr (assoc (match-string 0 str)
  84                                     tibetan-precomposition-rule-alist))
  85                         tibetan-precomposed-transcription-alist)))
  86           (setq ch (substring str i (1+ i))
  87                 i (1+ i)
  88                 this-trans
  89                 (car (or (rassoc ch tibetan-consonant-transcription-alist)
  90                          (rassoc ch tibetan-vowel-transcription-alist)
  91                          (rassoc ch tibetan-subjoined-transcription-alist)))))
  92         (setq trans (cons this-trans trans))))
  93     (apply 'concat (nreverse trans))))
  94
  95 ;;;###autoload
  96 (defun tibetan-transcription-to-tibetan (str)
  97   "Convert Tibetan Roman string STR to Tibetan character string.
  98 The returned string has no composition information."
  99   (let (;; Case is significant.
 100         (case-fold-search nil)
 101         (idx 0)
 102         ;; Accumulate Tibetan strings here in reverse order.
 103         (t-str-list nil)
 104         i subtrans)
 105     (while (setq i (string-match tibetan-regexp str idx))
 106       (if (< idx i)
 107           ;; STR contains a pattern that doesn't match Tibetan
 108           ;; transcription.  Include the pattern as is.
 109           (setq t-str-list (cons (substring str idx i) t-str-list)))
 110       (setq subtrans (match-string 0 str)
 111             idx (match-end 0))
 112       (let ((t-char (cdr (assoc subtrans
 113                                 tibetan-precomposed-transcription-alist))))
 114         (if t-char
 115             ;; SUBTRANS corresponds to a transcription for
 116             ;; precomposable Tibetan sequence.
 117             (setq t-char (car (rassoc t-char
 118                                       tibetan-precomposition-rule-alist)))
 119           (setq t-char
 120                 (cdr
 121                  (or (assoc subtrans tibetan-consonant-transcription-alist)
 122                      (assoc subtrans tibetan-vowel-transcription-alist)
 123                      (assoc subtrans tibetan-modifier-transcription-alist)
 124                      (assoc subtrans tibetan-subjoined-transcription-alist)))))
 125         (setq t-str-list (cons t-char t-str-list))))
 126     (if (< idx (length str))
 127         (setq t-str-list (cons (substring str idx) t-str-list)))
 128     (apply 'concat (nreverse t-str-list))))
 129
 130 ;;;
 131 ;;; Functions for composing/decomposing Tibetan sequence.
 132 ;;;
 133 ;;; A Tibetan syllable is typically structured as follows:
 134 ;;;
 135 ;;;      [Prefix] C [C+] V [M] [Suffix [Post suffix]]
 136 ;;;
 137 ;;; where C's are all vertically stacked, V appears below or above
 138 ;;; consonant cluster and M is always put above the C[C+]V combination.
 139 ;;; (Sanskrit visarga, though it is a vowel modifier, is considered
 140 ;;;  to be a punctuation.)
 141 ;;;
 142 ;;; Here are examples of the words "bsgrubs" and "hfauM"
 143 ;;;
 144 ;;;            \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
 145 ;;;
 146 ;;;                             M
 147 ;;;             b s b s         h
 148 ;;;               g             fa
 149 ;;;               r             u
 150 ;;;               u
 151 ;;;
 152 ;;; 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
 153 ;;; forms when they are used as subjoined consonant.  Consonant `r'
 154 ;;; takes another special form when used as superjoined in such a case
 155 ;;; as "rka", while it does not change its form when conjoined with
 156 ;;; subjoined `'', `w' or `y' as in "rwa", "rya".
 157
 158 ;; Append a proper composition rule and glyph to COMPONENTS to compose
 159 ;; CHAR with a composition that has COMPONENTS.
 160
 161 (defun tibetan-add-components (components char)
 162   (let ((last (last components))
 163         (stack-upper '(tc . bc))
 164         (stack-under '(bc . tc))
 165         rule comp-vowel tmp)
 166     ;; Special treatment for 'a chung.
 167     ;; If 'a follows a consonant, turn it into the subjoined form.
 168     ;; * Disabled by Tomabechi 2000/06/09 *
 169     ;; Because in Unicode, \e$(7"A\e(B may follow directly a consonant without
 170     ;; any intervening vowel, as in \e4\e$(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$(7"A\e0"A\e1\e(B
 171     ;;(if (and (= char ?\e$(7"A\e(B)
 172     ;;       (aref (char-category-set (car last)) ?0))
 173     ;;  (setq char ?\e$(7"R\e(B)) ;; modified for new font by Tomabechi 1999/12/10
 174
 175     ;; Composite vowel signs are decomposed before being added
 176     ;; Added by Tomabechi 2000/06/08
 177     (if (memq char '(?\e$(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))
 178         (setq comp-vowel
 179               (copy-sequence
 180                (cddr (assoc (char-to-string char)
 181                             tibetan-composite-vowel-alist)))
 182               char
 183               (cadr (assoc (char-to-string char)
 184                            tibetan-composite-vowel-alist))))
 185     (cond
 186      ;; Compose upper vowel sign vertically over.
 187      ((aref (char-category-set char) ?2)
 188       (setq rule stack-upper))
 189
 190      ;; Compose lower vowel sign vertically under.
 191      ((aref (char-category-set char) ?3)
 192       (if (eq char ?\e$(7"Q\e(B)          ;; `\e$(7"Q\e(B' should not visible when composed.
 193           (setq rule nil)
 194         (setq rule stack-under)))
 195      ;; Transform ra-mgo (superscribed r) if followed by a subjoined
 196      ;; consonant other than w, ', y, r.
 197      ((and (= (car last) ?\e$(7"C\e(B)
 198            (not (memq char '(?\e$(7#>\e(B ?\e$(7"R\e(B ?\e$(7#B\e(B ?\e$(7#C\e(B))))
 199       (setcar last ?\e$(7!"\e(B) ;; modified for newfont by Tomabechi 1999/12/10
 200       (setq rule stack-under))
 201      ;; Transform initial base consonant if followed by a subjoined
 202      ;; consonant but 'a.
 203      (t
 204       (let ((laststr (char-to-string (car last))))
 205         (if (and (/= char ?\e$(7"R\e(B) ;; modified for new font by Tomabechi
 206                  (string-match "[\e$(7"!\e(B-\e$(7"="?"@"D\e(B-\e$(7"J"K\e(B]" laststr))
 207             (setcar last (string-to-char
 208                           (cdr (assoc (char-to-string (car last))
 209                                       tibetan-base-to-subjoined-alist)))))
 210         (setq rule stack-under))))
 211
 212     (if rule
 213         (setcdr last (list rule char)))
 214     ;; Added by Tomabechi 2000/06/08
 215     (if comp-vowel
 216         (nconc last comp-vowel))
 217     ))
 218
 219 ;;;###autoload
 220 (defun tibetan-compose-string (str)
 221   "Compose Tibetan string STR."
 222   (let ((idx 0))
 223     ;; `\e$(7"A\e(B' is included in the pattern for subjoined consonants
 224     ;; because we treat it specially in tibetan-add-components.
 225     ;; (This feature is removed by Tomabechi 2000/06/08)
 226     (while (setq idx (string-match tibetan-composable-pattern str idx))
 227       (let ((from idx)
 228             (to (match-end 0))
 229             components)
 230         (if (eq (string-match tibetan-precomposition-rule-regexp str idx) idx)
 231             (setq idx (match-end 0)
 232                   components
 233                   (list (string-to-char
 234                          (cdr
 235                           (assoc (match-string 0 str)
 236                                  tibetan-precomposition-rule-alist)))))
 237           (setq components (list (aref str idx))
 238                 idx (1+ idx)))
 239         (while (< idx to)
 240           (tibetan-add-components components (aref str idx))
 241           (setq idx (1+ idx)))
 242         (compose-string str from to components))))
 243   str)
 244
 245 ;;;###autoload
 246 (defun tibetan-compose-region (beg end)
 247   "Compose Tibetan text the region BEG and END."
 248   (interactive "r")
 249   (let (str result chars)
 250     (save-excursion
 251       (save-restriction
 252         (narrow-to-region beg end)
 253         (goto-char (point-min))
 254         ;; `\e$(7"A\e(B' is included in the pattern for subjoined consonants
 255         ;; because we treat it specially in tibetan-add-components.
 256         ;; (This feature is removed by Tomabechi 2000/06/08)
 257         (while (re-search-forward tibetan-composable-pattern nil t)
 258           (let ((from (match-beginning 0))
 259                 (to (match-end 0))
 260                 components)
 261             (goto-char from)
 262             (if (looking-at tibetan-precomposition-rule-regexp)
 263                 (progn
 264                   (setq components
 265                         (list (string-to-char
 266                                (cdr
 267                                 (assoc (match-string 0)
 268                                        tibetan-precomposition-rule-alist)))))
 269                   (goto-char (match-end 0)))
 270               (setq components (list (char-after from)))
 271               (forward-char 1))
 272             (while (< (point) to)
 273               (tibetan-add-components components (following-char))
 274               (forward-char 1))
 275             (compose-region from to components)))))))
 276
 277 (defvar tibetan-decompose-precomposition-alist
 278   (mapcar (function (lambda (x) (cons (string-to-char (cdr x)) (car x))))
 279           tibetan-precomposition-rule-alist))
 280
 281 ;;;###autoload
 282 (defun tibetan-decompose-region (from to)
 283   "Decompose Tibetan text in the region FROM and TO.
 284 This is different from decompose-region because precomposed Tibetan characters
 285 are decomposed into normal Tibetan character sequences."
 286   (interactive "r")
 287   (save-restriction
 288     (narrow-to-region from to)
 289     (decompose-region from to)
 290     (goto-char from)
 291     (while (not (eobp))
 292       (let* ((char (following-char))
 293              (slot (assq char tibetan-decompose-precomposition-alist)))
 294         (if slot
 295             (progn
 296               (delete-char 1)
 297               (insert (cdr slot)))
 298           (forward-char 1))))))
 299
 300
 301 ;;;###autoload
 302 (defun tibetan-decompose-string (str)
 303   "Decompose Tibetan string STR.
 304 This is different from decompose-string because precomposed Tibetan characters
 305 are decomposed into normal Tibetan character sequences."
 306   (let ((new "")
 307         (len (length str))
 308         (idx 0)
 309         char slot)
 310     (while (< idx len)
 311       (setq char (aref str idx)
 312             slot (assq (aref str idx) tibetan-decompose-precomposition-alist)
 313             new (concat new (if slot (cdr slot) (char-to-string char)))
 314             idx (1+ idx)))
 315     new))
 316
 317 ;;;###autoload
 318 (defun tibetan-composition-function (from to pattern &optional string)
 319   (if string
 320       (tibetan-compose-string string)
 321     (tibetan-compose-region from to))
 322   (- to from))
 323
 324 ;;;
 325 ;;; This variable is used to avoid repeated decomposition.
 326 ;;;
 327 (setq-default tibetan-decomposed nil)
 328
 329 ;;;###autoload
 330 (defun tibetan-decompose-buffer ()
 331   "Decomposes Tibetan characters in the buffer into their components.
 332 See also the documentation of the function `tibetan-decompose-region'."
 333   (interactive)
 334   (make-local-variable 'tibetan-decomposed)
 335   (cond ((not tibetan-decomposed)
 336          (tibetan-decompose-region (point-min) (point-max))
 337          (setq tibetan-decomposed t))))
 338
 339 ;;;###autoload
 340 (defun tibetan-compose-buffer ()
 341   "Composes Tibetan character components in the buffer.
 342 See also docstring of the function tibetan-compose-region."
 343   (interactive)
 344   (make-local-variable 'tibetan-decomposed)
 345   (tibetan-compose-region (point-min) (point-max))
 346   (setq tibetan-decomposed nil))
 347
 348 ;;;###autoload
 349 (defun tibetan-post-read-conversion (len)
 350   (save-excursion
 351     (save-restriction
 352       (let ((buffer-modified-p (buffer-modified-p)))
 353         (narrow-to-region (point) (+ (point) len))
 354         (tibetan-compose-region (point-min) (point-max))
 355         (set-buffer-modified-p buffer-modified-p)
 356         (make-local-variable 'tibetan-decomposed)
 357         (setq tibetan-decomposed nil)
 358         (- (point-max) (point-min))))))
 359
 360
 361 ;;;###autoload
 362 (defun tibetan-pre-write-conversion (from to)
 363   (setq tibetan-decomposed-temp tibetan-decomposed)
 364   (let ((old-buf (current-buffer)))
 365     (set-buffer (generate-new-buffer " *temp*"))
 366     (if (stringp from)
 367         (insert from)
 368       (insert-buffer-substring old-buf from to))
 369     (if (not tibetan-decomposed-temp)
 370         (tibetan-decompose-region (point-min) (point-max)))
 371     ;; Should return nil as annotations.
 372     nil))
 373
 374 \f
 375 ;;;
 376 ;;; Unicode-related definitions.
 377 ;;;
 378
 379 (defvar tibetan-canonicalize-for-unicode-alist
 380   '(("\e$(7"Q\e(B" . "")  ;; remove vowel a
 381     ("\e$(7"T\e(B" . "\e$(7"R"S\e(B") ;; decompose vowels whose use is ``discouraged'' in Unicode 3.0
 382     ("\e$(7"V\e(B" . "\e$(7"R"U\e(B")
 383     ("\e$(7"W\e(B" . "\e$(7#C"a\e(B")
 384     ("\e$(7"X\e(B" . "\e$(7#C"R"a\e(B")
 385     ("\e$(7"Y\e(B" . "\e$(7#D"a\e(B")
 386     ("\e$(7"Z\e(B" . "\e$(7#D"R"a\e(B")
 387     ("\e$(7"b\e(B" . "\e$(7"R"a\e(B"))
 388   "Rules for canonicalizing Tibetan vowels for Unicode.")
 389
 390 (defvar tibetan-canonicalize-for-unicode-regexp
 391   "[\e$(7"Q"T"V"W"X"Y"Z"b\e(B]"
 392   "Regexp for Tibetan vowels to be canonicalized in Unicode.")
 393
 394 (defun tibetan-canonicalize-for-unicode-region (from to)
 395   (save-restriction
 396     (narrow-to-region from to)
 397     (goto-char from)
 398     (while (re-search-forward tibetan-canonicalize-for-unicode-regexp nil t)
 399       (let (
 400             ;;(from (match-beginning 0))
 401             ;;(to (match-end 0))
 402             (canonical-form
 403              (cdr (assoc (match-string 0)
 404                          tibetan-canonicalize-for-unicode-alist))))
 405         ;;(goto-char from)
 406         ;;(delete-region from to)
 407         ;;(insert canonical-form)
 408         (replace-match canonical-form)
 409         ))))
 410
 411 (defvar tibetan-strict-unicode t
 412   "*Flag to control Tibetan canonicalizing for Unicode.
 413
 414 If non-nil, the vowel a is removed and composite vowels are decomposed
 415 before writing buffer in Unicode.  See also
 416 `tibetan-canonicalize-for-unicode-regexp' and
 417 `tibetan-canonicalize-for-unicode-alist'.")
 418
 419 ;;;###autoload
 420 (defun tibetan-pre-write-canonicalize-for-unicode (from to)
 421   (let ((old-buf (current-buffer))
 422         (strict-unicode tibetan-strict-unicode))
 423     (set-buffer (generate-new-buffer " *temp*"))
 424     (if (stringp from)
 425         (insert from)
 426       (insert-buffer-substring old-buf from to))
 427     (if strict-unicode
 428         (tibetan-canonicalize-for-unicode-region (point-min) (point-max)))
 429     ;; Should return nil as annotations.
 430     nil))
 431
 432 (provide 'tibet-util)
 433
 434 ;;; arch-tag: 7a7333e8-1584-446c-b39c-a02b9def265d
 435 ;;; tibet-util.el ends here