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, 2007, 2008, 2009, 2010
   4 ;;   Free Software Foundation, Inc.
   5 ;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   6 ;;   2005, 2006, 2007, 2008, 2009, 2010
   7 ;;   National Institute of Advanced Industrial Science and Technology (AIST)
   8 ;;   Registration Number H14PRO021
   9
  10 ;; Author: Toru TOMABECHI <Toru.Tomabechi@orient.unil.ch>
  11 ;; Keywords: multilingual, Tibetan
  12 ;; Created: Feb. 17. 1997
  13
  14 ;; This file is part of GNU Emacs.
  15
  16 ;; GNU Emacs is free software: you can redistribute it and/or modify
  17 ;; it under the terms of the GNU General Public License as published by
  18 ;; the Free Software Foundation, either version 3 of the License, or
  19 ;; (at your option) any later version.
  20
  21 ;; GNU Emacs is distributed in the hope that it will be useful,
  22 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  23 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24 ;; GNU General Public License for more details.
  25
  26 ;; You should have received a copy of the GNU General Public License
  27 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  28
  29 ;;; History:
  30 ;; 1997.03.13 Modification in treatment of text properties;
  31 ;;            Support for some special signs and punctuations.
  32 ;; 1999.10.25 Modification for a new composition way by K.Handa.
  33
  34 ;;; Commentary:
  35
  36 ;;; Code:
  37
  38 (defconst tibetan-obsolete-glyphs
  39   `(("\e$(7!=\e(B" . "\e$(7!=\e(B")                 ; 2 col <-> 1 col
  40     ("\e$(7!?\e(B" . "\e$(7!?\e(B")
  41     ("\e$(7!@\e(B" . "\e$(7!@\e(B")
  42     ("\e$(7!A\e(B" . "\e$(7!A\e(B")
  43     ("\e$(7"`\e(B" . "\e$(7"`\e(B")
  44     ("\e$(7!;\e(B" . "\e$(7!;\e(B")
  45     ("\e$(7!D\e(B" . "\e$(7!D\e(B")
  46     ;; Yes these are dirty. But ...
  47     ("\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]))
  48     ("\e$(7!4!5!5\e(B" . ,(compose-string
  49                   "\e$(7#R#S#S#S\e(B" 0 4
  50                   [?\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]))
  51     ("\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$(7#S\e(B]))
  52     ("\e$(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]))
  53     ("\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]))))
  54
  55 ;;;###autoload
  56 (defun tibetan-char-p (ch)
  57   "Check if char CH is Tibetan character.
  58 Returns non-nil if CH is Tibetan. Otherwise, returns nil."
  59   (memq (char-charset ch) '(tibetan tibetan-1-column)))
  60
  61 ;;; Functions for Tibetan <-> Tibetan-transcription.
  62
  63 ;;;###autoload
  64 (defun tibetan-tibetan-to-transcription (str)
  65   "Transcribe Tibetan string STR and return the corresponding Roman string."
  66   (let (;; Accumulate transcriptions here in reverse order.
  67         (trans nil)
  68         (len (length str))
  69         (i 0)
  70         ch this-trans)
  71     (while (< i len)
  72       (let ((idx (string-match tibetan-precomposition-rule-regexp str i)))
  73         (if (eq idx i)
  74             ;; Ith character and the followings matches precomposable
  75             ;; Tibetan sequence.
  76             (setq i (match-end 0)
  77                   this-trans
  78                   (car (rassoc
  79                         (cdr (assoc (match-string 0 str)
  80                                     tibetan-precomposition-rule-alist))
  81                         tibetan-precomposed-transcription-alist)))
  82           (setq ch (substring str i (1+ i))
  83                 i (1+ i)
  84                 this-trans
  85                 (car (or (rassoc ch tibetan-consonant-transcription-alist)
  86                          (rassoc ch tibetan-vowel-transcription-alist)
  87                          (rassoc ch tibetan-subjoined-transcription-alist)))))
  88         (setq trans (cons this-trans trans))))
  89     (apply 'concat (nreverse trans))))
  90
  91 ;;;###autoload
  92 (defun tibetan-transcription-to-tibetan (str)
  93   "Convert Tibetan Roman string STR to Tibetan character string.
  94 The returned string has no composition information."
  95   (let (;; Case is significant.
  96         (case-fold-search nil)
  97         (idx 0)
  98         ;; Accumulate Tibetan strings here in reverse order.
  99         (t-str-list nil)
 100         i subtrans)
 101     (while (setq i (string-match tibetan-regexp str idx))
 102       (if (< idx i)
 103           ;; STR contains a pattern that doesn't match Tibetan
 104           ;; transcription.  Include the pattern as is.
 105           (setq t-str-list (cons (substring str idx i) t-str-list)))
 106       (setq subtrans (match-string 0 str)
 107             idx (match-end 0))
 108       (let ((t-char (cdr (assoc subtrans
 109                                 tibetan-precomposed-transcription-alist))))
 110         (if t-char
 111             ;; SUBTRANS corresponds to a transcription for
 112             ;; precomposable Tibetan sequence.
 113             (setq t-char (car (rassoc t-char
 114                                       tibetan-precomposition-rule-alist)))
 115           (setq t-char
 116                 (cdr
 117                  (or (assoc subtrans tibetan-consonant-transcription-alist)
 118                      (assoc subtrans tibetan-vowel-transcription-alist)
 119                      (assoc subtrans tibetan-modifier-transcription-alist)
 120                      (assoc subtrans tibetan-subjoined-transcription-alist)))))
 121         (setq t-str-list (cons t-char t-str-list))))
 122     (if (< idx (length str))
 123         (setq t-str-list (cons (substring str idx) t-str-list)))
 124     (apply 'concat (nreverse t-str-list))))
 125
 126 ;;;
 127 ;;; Functions for composing/decomposing Tibetan sequence.
 128 ;;;
 129 ;;; A Tibetan syllable is typically structured as follows:
 130 ;;;
 131 ;;;      [Prefix] C [C+] V [M] [Suffix [Post suffix]]
 132 ;;;
 133 ;;; where C's are all vertically stacked, V appears below or above
 134 ;;; consonant cluster and M is always put above the C[C+]V combination.
 135 ;;; (Sanskrit visarga, though it is a vowel modifier, is considered
 136 ;;;  to be a punctuation.)
 137 ;;;
 138 ;;; Here are examples of the words "bsgrubs" and "hfauM"
 139 ;;;
 140 ;;;            \e$(7"7"G###C"U"7"G\e(B            \e$(7"H"R"U"_\e(B
 141 ;;;
 142 ;;;                             M
 143 ;;;             b s b s         h
 144 ;;;               g             fa
 145 ;;;               r             u
 146 ;;;               u
 147 ;;;
 148 ;;; 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
 149 ;;; forms when they are used as subjoined consonant.  Consonant `r'
 150 ;;; takes another special form when used as superjoined in such a case
 151 ;;; as "rka", while it does not change its form when conjoined with
 152 ;;; subjoined `'', `w' or `y' as in "rwa", "rya".
 153
 154 ;; Append a proper composition rule and glyph to COMPONENTS to compose
 155 ;; CHAR with a composition that has COMPONENTS.
 156
 157 (defun tibetan-add-components (components char)
 158   (let ((last (last components))
 159         (stack-upper '(tc . bc))
 160         (stack-under '(bc . tc))
 161         rule comp-vowel tmp)
 162     ;; Special treatment for 'a chung.
 163     ;; If 'a follows a consonant, turn it into the subjoined form.
 164     ;; * Disabled by Tomabechi 2000/06/09 *
 165     ;; Because in Unicode, \e$(7"A\e(B may follow directly a consonant without
 166     ;; any intervening vowel, as in \e$(7"9"""Q"A!;\e(B=\e$(7"9\e(B \e$(7""\e(B \e$(7"A\e(B not \e$(7"9\e(B \e$(7""\e(B \e$(7"Q\e(B \e$(7"A\e(B
 167     ;;(if (and (= char ?\e$(7"A\e(B)
 168     ;;       (aref (char-category-set (car last)) ?0))
 169     ;;  (setq char ?\e$(7"R\e(B)) ;; modified for new font by Tomabechi 1999/12/10
 170
 171     ;; Composite vowel signs are decomposed before being added
 172     ;; Added by Tomabechi 2000/06/08
 173     (if (memq char '(?\e$(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))
 174         (setq comp-vowel
 175               (copy-sequence
 176                (cddr (assoc (char-to-string char)
 177                             tibetan-composite-vowel-alist)))
 178               char
 179               (cadr (assoc (char-to-string char)
 180                            tibetan-composite-vowel-alist))))
 181     (cond
 182      ;; Compose upper vowel sign vertically over.
 183      ((aref (char-category-set char) ?2)
 184       (setq rule stack-upper))
 185
 186      ;; Compose lower vowel sign vertically under.
 187      ((aref (char-category-set char) ?3)
 188       (if (or (eq char ?\e$(7"Q\e(B) ;; `\e$(7"Q\e(B' and `\e$,1FP\e(B' should not visible when composed.
 189               (eq char #xF70))
 190           (setq rule nil)
 191         (setq rule stack-under)))
 192      ;; Transform ra-mgo (superscribed r) if followed by a subjoined
 193      ;; consonant other than w, ', y, r.
 194      ((and (= (car last) ?\e$(7"C\e(B)
 195            (not (memq char '(?\e$(7#>\e(B ?\e$(7"R\e(B ?\e$(7#B\e(B ?\e$(7#C\e(B))))
 196       (setcar last ?\e$(7!"\e(B) ;; modified for newfont by Tomabechi 1999/12/10
 197       (setq rule stack-under))
 198      ;; Transform initial base consonant if followed by a subjoined
 199      ;; consonant but 'a.
 200      (t
 201       (let ((laststr (char-to-string (car last))))
 202         (if (and (/= char ?\e$(7"R\e(B) ;; modified for new font by Tomabechi
 203                  (string-match "[\e$(7"!\e(B-\e$(7"="?"@"D\e(B-\e$(7"J"K\e(B]" laststr))
 204             (setcar last (string-to-char
 205                           (cdr (assoc (char-to-string (car last))
 206                                       tibetan-base-to-subjoined-alist)))))
 207         (setq rule stack-under))))
 208
 209     (if rule
 210         (setcdr last (list rule char)))
 211     ;; Added by Tomabechi 2000/06/08
 212     (if comp-vowel
 213         (nconc last comp-vowel))
 214     ))
 215
 216 ;;;###autoload
 217 (defun tibetan-compose-string (str)
 218   "Compose Tibetan string STR."
 219   (let ((idx 0))
 220     ;; `\e$(7"A\e(B' is included in the pattern for subjoined consonants
 221     ;; because we treat it specially in tibetan-add-components.
 222     ;; (This feature is removed by Tomabechi 2000/06/08)
 223     (while (setq idx (string-match tibetan-composable-pattern str idx))
 224       (let ((from idx)
 225             (to (match-end 0))
 226             components)
 227         (if (eq (string-match tibetan-precomposition-rule-regexp str idx) idx)
 228             (setq idx (match-end 0)
 229                   components
 230                   (list (string-to-char
 231                          (cdr
 232                           (assoc (match-string 0 str)
 233                                  tibetan-precomposition-rule-alist)))))
 234           (setq components (list (aref str idx))
 235                 idx (1+ idx)))
 236         (while (< idx to)
 237           (tibetan-add-components components (aref str idx))
 238           (setq idx (1+ idx)))
 239         (compose-string str from to components))))
 240   str)
 241
 242 ;;;###autoload
 243 (defun tibetan-compose-region (beg end)
 244   "Compose Tibetan text the region BEG and END."
 245   (interactive "r")
 246   (let (str result chars)
 247     (save-excursion
 248       (save-restriction
 249         (narrow-to-region beg end)
 250         (goto-char (point-min))
 251         ;; `\e$(7"A\e(B' is included in the pattern for subjoined consonants
 252         ;; because we treat it specially in tibetan-add-components.
 253         ;; (This feature is removed by Tomabechi 2000/06/08)
 254         (while (re-search-forward tibetan-composable-pattern nil t)
 255           (let ((from (match-beginning 0))
 256                 (to (match-end 0))
 257                 components)
 258             (goto-char from)
 259             (if (looking-at tibetan-precomposition-rule-regexp)
 260                 (progn
 261                   (setq components
 262                         (list (string-to-char
 263                                (cdr
 264                                 (assoc (match-string 0)
 265                                        tibetan-precomposition-rule-alist)))))
 266                   (goto-char (match-end 0)))
 267               (setq components (list (char-after from)))
 268               (forward-char 1))
 269             (while (< (point) to)
 270               (tibetan-add-components components (following-char))
 271               (forward-char 1))
 272             (compose-region from to components)))))))
 273
 274 (defvar tibetan-decompose-precomposition-alist
 275   (mapcar (function (lambda (x) (cons (string-to-char (cdr x)) (car x))))
 276           tibetan-precomposition-rule-alist))
 277
 278 ;;;###autoload
 279 (defun tibetan-decompose-region (from to)
 280   "Decompose Tibetan text in the region FROM and TO.
 281 This is different from decompose-region because precomposed Tibetan characters
 282 are decomposed into normal Tibetan character sequences."
 283   (interactive "r")
 284   (save-restriction
 285     (narrow-to-region from to)
 286     (decompose-region from to)
 287     (goto-char from)
 288     (while (not (eobp))
 289       (let* ((char (following-char))
 290              (slot (assq char tibetan-decompose-precomposition-alist)))
 291         (if slot
 292             (progn
 293               (delete-char 1)
 294               (insert (cdr slot)))
 295           (forward-char 1))))))
 296
 297
 298 ;;;###autoload
 299 (defun tibetan-decompose-string (str)
 300   "Decompose Tibetan string STR.
 301 This is different from decompose-string because precomposed Tibetan characters
 302 are decomposed into normal Tibetan character sequences."
 303   (let ((new "")
 304         (len (length str))
 305         (idx 0)
 306         char slot)
 307     (while (< idx len)
 308       (setq char (aref str idx)
 309             slot (assq (aref str idx) tibetan-decompose-precomposition-alist)
 310             new (concat new (if slot (cdr slot) (char-to-string char)))
 311             idx (1+ idx)))
 312     new))
 313
 314 ;;;
 315 ;;; This variable is used to avoid repeated decomposition.
 316 ;;;
 317 (setq-default tibetan-decomposed nil)
 318
 319 ;;;###autoload
 320 (defun tibetan-decompose-buffer ()
 321   "Decomposes Tibetan characters in the buffer into their components.
 322 See also the documentation of the function `tibetan-decompose-region'."
 323   (interactive)
 324   (make-local-variable 'tibetan-decomposed)
 325   (cond ((not tibetan-decomposed)
 326          (tibetan-decompose-region (point-min) (point-max))
 327          (setq tibetan-decomposed t))))
 328
 329 ;;;###autoload
 330 (defun tibetan-compose-buffer ()
 331   "Composes Tibetan character components in the buffer.
 332 See also docstring of the function tibetan-compose-region."
 333   (interactive)
 334   (make-local-variable 'tibetan-decomposed)
 335   (tibetan-compose-region (point-min) (point-max))
 336   (setq tibetan-decomposed nil))
 337
 338 ;;;###autoload
 339 (defun tibetan-post-read-conversion (len)
 340   (save-excursion
 341     (save-restriction
 342       (let ((buffer-modified-p (buffer-modified-p)))
 343         (narrow-to-region (point) (+ (point) len))
 344         (tibetan-compose-region (point-min) (point-max))
 345         (set-buffer-modified-p buffer-modified-p)
 346         (make-local-variable 'tibetan-decomposed)
 347         (setq tibetan-decomposed nil)
 348         (- (point-max) (point-min))))))
 349
 350
 351 ;;;###autoload
 352 (defun tibetan-pre-write-conversion (from to)
 353   (setq tibetan-decomposed-temp tibetan-decomposed)
 354   (let ((old-buf (current-buffer)))
 355     (set-buffer (generate-new-buffer " *temp*"))
 356     (if (stringp from)
 357         (insert from)
 358       (insert-buffer-substring old-buf from to))
 359     (if (not tibetan-decomposed-temp)
 360         (tibetan-decompose-region (point-min) (point-max)))
 361     ;; Should return nil as annotations.
 362     nil))
 363
 364 \f
 365 ;;;
 366 ;;; Unicode-related definitions.
 367 ;;;
 368
 369 (defvar tibetan-canonicalize-for-unicode-alist
 370   '(("\e$(7"Q\e(B" . "")  ;; remove vowel a
 371     ("\e$(7"T\e(B" . "\e$(7"R"S\e(B") ;; decompose vowels whose use is ``discouraged'' in Unicode 3.0
 372     ("\e$(7"V\e(B" . "\e$(7"R"U\e(B")
 373     ("\e$(7"W\e(B" . "\e$(7#C"a\e(B")
 374     ("\e$(7"X\e(B" . "\e$(7#C"R"a\e(B")
 375     ("\e$(7"Y\e(B" . "\e$(7#D"a\e(B")
 376     ("\e$(7"Z\e(B" . "\e$(7#D"R"a\e(B")
 377     ("\e$(7"b\e(B" . "\e$(7"R"a\e(B"))
 378   "Rules for canonicalizing Tibetan vowels for Unicode.")
 379
 380 (defvar tibetan-canonicalize-for-unicode-regexp
 381   "[\e$(7"Q"T"V"W"X"Y"Z"b\e(B]"
 382   "Regexp for Tibetan vowels to be canonicalized in Unicode.")
 383
 384 (defun tibetan-canonicalize-for-unicode-region (from to)
 385   (save-restriction
 386     (narrow-to-region from to)
 387     (goto-char from)
 388     (while (re-search-forward tibetan-canonicalize-for-unicode-regexp nil t)
 389       (let (
 390             ;;(from (match-beginning 0))
 391             ;;(to (match-end 0))
 392             (canonical-form
 393              (cdr (assoc (match-string 0)
 394                          tibetan-canonicalize-for-unicode-alist))))
 395         ;;(goto-char from)
 396         ;;(delete-region from to)
 397         ;;(insert canonical-form)
 398         (replace-match canonical-form)
 399         ))))
 400
 401 (defvar tibetan-strict-unicode t
 402   "*Flag to control Tibetan canonicalizing for Unicode.
 403
 404 If non-nil, the vowel a is removed and composite vowels are decomposed
 405 before writing buffer in Unicode.  See also
 406 `tibetan-canonicalize-for-unicode-regexp' and
 407 `tibetan-canonicalize-for-unicode-alist'.")
 408
 409 ;;;###autoload
 410 (defun tibetan-pre-write-canonicalize-for-unicode (from to)
 411   (let ((old-buf (current-buffer))
 412         (strict-unicode tibetan-strict-unicode))
 413     (set-buffer (generate-new-buffer " *temp*"))
 414     (if (stringp from)
 415         (insert from)
 416       (insert-buffer-substring old-buf from to))
 417     (if strict-unicode
 418         (tibetan-canonicalize-for-unicode-region (point-min) (point-max)))
 419     ;; Should return nil as annotations.
 420     nil))
 421
 422 (provide 'tibet-util)
 423
 424 ;; arch-tag: 7a7333e8-1584-446c-b39c-a02b9def265d
 425 ;;; tibet-util.el ends here