lisp/language/tml-util.el

   1 ;;; tml-util.el --- support for composing tamil characters  -*-coding: iso-2022-7bit;-*-
   2
   3 ;; Copyright (C) 2001 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: KAWABATA, Taichi <kawabata@m17n.org>
   6 ;; Keywords: multilingual, Indian, Tamil
   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 2, 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., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;; Created: Nov. 08. 2002
  26
  27 ;;; Commentary:
  28
  29 ;; This file provides character(Unicode) to glyph(CDAC) conversion and
  30 ;; composition of Tamil script characters.
  31
  32 ;;; Code:
  33
  34 ;; Tamil Composable Pattern
  35 ;;    C .. Consonants
  36 ;;    V .. Vowel
  37 ;;    H .. Pulli
  38 ;;    M .. Matra
  39 ;;    V .. Vowel
  40 ;;    A .. Anuswar
  41 ;;    D .. Chandrabindu
  42 ;; 1. vowel
  43 ;;  V
  44 ;; 2. syllable : only ligature-formed pattern forms composition.
  45 ;;  (CkHCs|C)(H|M)?
  46 ;; 3. sri special
  47 ;;  (CsHCrVi)
  48
  49 ;;  oririnal
  50 ;;  ((CH)?(CH)?(CH)?CH)?C(H|M?(A|D)?)?
  51
  52 (defconst tamil-consonant
  53   "[\e$,1<5\e(B-\e$,1<Y\e(B]")
  54
  55 (defconst tamil-composable-pattern
  56   (concat
  57    "\\([\e$,1<%\e(B-\e$,1<4\e(B]\\)\\|"
  58    "[\e$,1<"<#\e(B]\\|" ;; vowel modifier considered independent
  59    "\\(\\(?:\\(?:\e$,1<5<m<W\e(B\\)\\|[\e$,1<5\e(B-\e$,1<Y\e(B]\\)[\e$,1<m<^\e(B-\e$,1<l\e(B]?\\)\\|"
  60    "\\(\e$,1<W<m<P<`\e(B\\)")
  61   "Regexp matching a composable sequence of Tamil characters.")
  62
  63 ;;;###autoload
  64 (defun tamil-compose-region (from to)
  65   (interactive "r")
  66   (save-excursion
  67     (save-restriction
  68       (narrow-to-region from to)
  69       (goto-char (point-min))
  70       (while (re-search-forward tamil-composable-pattern nil t)
  71         (tamil-compose-syllable-region (match-beginning 0)
  72                                             (match-end 0))))))
  73 (defun tamil-compose-string (string)
  74   (with-temp-buffer
  75     (insert (decompose-string string))
  76     (tamil-compose-region (point-min) (point-max))
  77     (buffer-string)))
  78
  79 ;;;###autoload
  80 (defun tamil-post-read-conversion (len)
  81   (save-excursion
  82     (save-restriction
  83       (let ((buffer-modified-p (buffer-modified-p)))
  84         (narrow-to-region (point) (+ (point) len))
  85         (tamil-compose-region (point-min) (point-max))
  86         (set-buffer-modified-p buffer-modified-p)
  87         (- (point-max) (point-min))))))
  88
  89 (defun tamil-range (from to)
  90   "Make the list of the integers of range FROM to TO."
  91   (let (result)
  92     (while (<= from to) (setq result (cons to result) to (1- to))) result))
  93
  94 (defun tamil-regexp-of-hashtbl-keys (hashtbl)
  95   "Return a regular expression that matches all keys in hashtable HASHTBL."
  96   (let ((max-specpdl-size 1000))
  97     (regexp-opt
  98      (sort
  99       (let (dummy)
 100         (maphash (function (lambda (key val) (setq dummy (cons key dummy)))) hashtbl)
 101         dummy)
 102       (function (lambda (x y) (> (length x) (length y))))))))
 103
 104
 105 ;;;###autoload
 106 (defun tamil-composition-function (from to pattern  &optional string)
 107   "Compose Tamil characters in REGION, or STRING if specified.
 108 Assume that the REGION or STRING must fully match the composable
 109 PATTERN regexp."
 110   (if string (tamil-compose-syllable-string string)
 111     (tamil-compose-syllable-region from to))
 112   (- to from))
 113
 114 ;; Register a function to compose Tamil characters.
 115 (mapc
 116  (function (lambda (ucs)
 117    (aset composition-function-table (decode-char 'ucs ucs)
 118          (list (cons tamil-composable-pattern
 119                      'tamil-composition-function)))))
 120  (nconc '(#x0b82 #x0b83) (tamil-range #x0b85 #x0bb9)))
 121
 122 ;; Notes on conversion steps.
 123
 124 ;; 1. chars to glyphs
 125 ;; Simple replacement of characters to glyphs is done.
 126
 127 ;; 2. glyphs reordering.
 128 ;; following "\e$,4)j\e(B", "\e$,4)k\e(B", "\e$,4)l\e(B" goes to the front.
 129
 130 ;; 3. glyphs to glyphs
 131 ;; reordered vowels are ligatured to consonants.
 132
 133 ;; 4. Composition.
 134 ;; left modifiers will be attached at the left.
 135 ;; others will be attached right.
 136
 137 (defvar tml-char-glyph
 138   '(;; various signs
 139     ;;("\e$,1<"\e(B" . "")
 140     ("\e$,1<#\e(B" . "\e$,4*G\e(B")
 141     ;; Independent Vowels
 142     ("\e$,1<%\e(B" . "\e$,4*<\e(B")
 143     ("\e$,1<&\e(B" . "\e$,4*=\e(B")
 144     ("\e$,1<'\e(B" . "\e$,4*>\e(B")
 145     ("\e$,1<(\e(B" . "\e$,4*?\e(B")
 146     ("\e$,1<)\e(B" . "\e$,4*@\e(B")
 147     ("\e$,1<*\e(B" . "\e$,4*A\e(B")
 148     ("\e$,1<.\e(B" . "\e$,4*B\e(B")
 149     ("\e$,1</\e(B" . "\e$,4*C\e(B")
 150     ("\e$,1<0\e(B" . "\e$,4*D\e(B")
 151     ("\e$,1<2\e(B" . "\e$,4*E\e(B")
 152     ("\e$,1<3\e(B" . "\e$,4*F\e(B")
 153     ("\e$,1<4\e(B" . "\e$,4*E*W\e(B")
 154     ;; Consonants
 155     ("\e$,1<5<m<W<m\e(B" . "\e$,4):\e(B")   ; ks.
 156     ("\e$,1<5<m<W\e(B" . "\e$,4*^\e(B")     ; ks
 157     ("\e$,1<5\e(B" . "\e$,4*H\e(B")
 158
 159     ("\e$,1<9\e(B" . "\e$,4*I\e(B")
 160     ("\e$,1<:\e(B" . "\e$,4*J\e(B")
 161     ("\e$,1<<\e(B" . "\e$,4*\\e(B")
 162     ("\e$,1<<<m\e(B" . "\e$,4)8\e(B")
 163     ("\e$,1<>\e(B" . "\e$,4*K\e(B")
 164     ("\e$,1<?\e(B" . "\e$,4*L\e(B")
 165     ("\e$,1<C\e(B" . "\e$,4*M\e(B")
 166     ("\e$,1<D\e(B" . "\e$,4*N\e(B")
 167     ("\e$,1<H\e(B" . "\e$,4*O\e(B")
 168     ("\e$,1<I\e(B" . "\e$,4*Y\e(B")
 169     ("\e$,1<I<m\e(B" . "\e$,4)a\e(B")
 170     ("\e$,1<J\e(B" . "\e$,4*P\e(B")
 171     ("\e$,1<N\e(B" . "\e$,4*Q\e(B")
 172     ("\e$,1<O\e(B" . "\e$,4*R\e(B")
 173     ("\e$,1<P\e(B" . "\e$,4*S\e(B")
 174     ("\e$,1<Q\e(B" . "\e$,4*X\e(B")
 175     ("\e$,1<R\e(B" . "\e$,4*T\e(B")
 176     ("\e$,1<S\e(B" . "\e$,4*W\e(B")
 177     ("\e$,1<T\e(B" . "\e$,4*V\e(B")
 178     ("\e$,1<U\e(B" . "\e$,4*U\e(B")
 179     ("\e$,1<W\e(B" . "\e$,4*[\e(B")
 180     ("\e$,1<W<m\e(B" . "\e$,4)7\e(B")
 181     ("\e$,1<W<m<P<`\e(B" . "\e$,4*_\e(B")
 182     ("\e$,1<X\e(B" . "\e$,4*Z\e(B")
 183     ("\e$,1<X<m\e(B" . "\e$,4)6\e(B")
 184     ("\e$,1<Y\e(B" . "\e$,4*]\e(B")
 185     ("\e$,1<Y<m\e(B" . "\e$,4)9\e(B")
 186
 187     ;; Dependent vowel signs
 188     ("\e$,1<^\e(B" . "\e$,4)c\e(B")
 189     ("\e$,1<_\e(B" . "\e$,4)d\e(B")
 190     ("\e$,1<`\e(B" . "\e$,4)f\e(B")
 191     ("\e$,1<a\e(B" . "\e$,4)g\e(B")
 192     ("\e$,1<b\e(B" . "\e$,4)h\e(B")
 193     ("\e$,1<f\e(B" . "\e$,4)j\e(B")
 194     ("\e$,1<g\e(B" . "\e$,4)k\e(B")
 195     ("\e$,1<h\e(B" . "\e$,4)l\e(B")
 196     ("\e$,1<j\e(B" . "\e$,4)j)c\e(B")
 197     ("\e$,1<k\e(B" . "\e$,4)k)c\e(B")
 198     ("\e$,1<l\e(B" . "\e$,4)j*W\e(B")
 199
 200     ;; Various signs
 201     ("\e$,1<m\e(B" . "\e$,4)b\e(B")
 202     ("\e$,1<w\e(B" . "nil") ;; not supported?
 203     ))
 204
 205 (defvar tml-char-glyph-hash
 206   (let* ((hash (make-hash-table :test 'equal)))
 207     (mapc (function (lambda (x) (puthash (car x) (cdr x) hash)))
 208           tml-char-glyph)
 209     hash))
 210
 211 (defvar tml-char-glyph-regexp
 212   (tamil-regexp-of-hashtbl-keys tml-char-glyph-hash))
 213
 214 ;; Tamil languages needed to be reordered.
 215
 216 (defvar tml-consonants-regexp
 217   "[\e$,4*H*^*I*J*\*K*L*M*N*O*Y*P*Q*R*S*X*T*W*V*U*[*Z*]\e(B]")
 218
 219 (defvar tml-glyph-reorder-key-glyphs "[\e$,4)j)k)l\e(B]")
 220
 221 (defvar tml-glyph-reordering-regexp-list
 222   (cons
 223    (concat "\\(" tml-consonants-regexp "\\)\\([\e$,4)j)k)l\e(B]\\)") "\\2\\1"))
 224
 225 ;; Tamil vowel modifiers to be ligatured.
 226 (defvar tml-glyph-glyph
 227   '(
 228     ("\e$,4*H)d\e(B" . "\e$,4(a\e(B")       ; ki
 229     ("\e$,4*^)d\e(B" . "\e$,4(v\e(B")       ; ksi
 230     ("\e$,4*^)f\e(B" . "\e$,4)2\e(B")       ; ksi~
 231     ("\e$,4*I)d\e(B" . "\e$,4(b\e(B")       ; n^i
 232     ("\e$,4*J)d\e(B" . "\e$,4(c\e(B")       ; ci
 233     ("\e$,4*K)d\e(B" . "\e$,4(d\e(B")       ; n~i
 234     ("\e$,4*L)d\e(B" . "\e$,4)n\e(B")       ; t.i
 235     ("\e$,4*M)d\e(B" . "\e$,4(e\e(B")       ; n.i
 236     ("\e$,4*N)d\e(B" . "\e$,4(f\e(B")       ; ti
 237     ("\e$,4*O)d\e(B" . "\e$,4(g\e(B")       ; ni
 238     ("\e$,4*P)d\e(B" . "\e$,4(h\e(B")       ; pi
 239     ("\e$,4*Q)d\e(B" . "\e$,4(i\e(B")       ; mi
 240     ("\e$,4*R)d\e(B" . "\e$,4(j\e(B")       ; yi
 241     ("\e$,4*S)d\e(B" . "\e$,4(k\e(B")       ; ri
 242     ("\e$,4*T)d\e(B" . "\e$,4(l\e(B")       ; li
 243     ("\e$,4*U)d\e(B" . "\e$,4(m\e(B")       ; vi
 244     ("\e$,4*V)d\e(B" . "\e$,4(n\e(B")       ; l_i
 245     ("\e$,4*W)d\e(B" . "\e$,4(o\e(B")       ; l.i
 246     ("\e$,4*X)d\e(B" . "\e$,4(p\e(B")       ; r_i
 247     ("\e$,4*Y)d\e(B" . "\e$,4(q\e(B")       ; n_i
 248     ("\e$,4*Z)d\e(B" . "\e$,4(r\e(B")       ; si
 249     ("\e$,4*[)d\e(B" . "\e$,4(s\e(B")       ; s'i
 250     ("\e$,4*\)d\e(B" . "\e$,4(t\e(B")       ; ji
 251     ("\e$,4*])d\e(B" . "\e$,4(u\e(B")       ; hi
 252
 253     ("\e$,4*H)f\e(B" . "\e$,4(w\e(B")       ; ki~
 254     ("\e$,4*I)f\e(B" . "\e$,4(x\e(B")       ; n^i~
 255     ("\e$,4*J)f\e(B" . "\e$,4(y\e(B")       ; ci~
 256     ("\e$,4*K)f\e(B" . "\e$,4(z\e(B")       ; n~i~
 257     ("\e$,4*L)f\e(B" . "\e$,4)o\e(B")       ; t.i~
 258     ("\e$,4*M)f\e(B" . "\e$,4)!\e(B")       ; n.i~
 259     ("\e$,4*N)f\e(B" . "\e$,4)"\e(B")       ; ti~
 260     ("\e$,4*O)f\e(B" . "\e$,4)#\e(B")       ; ni~
 261     ("\e$,4*P)f\e(B" . "\e$,4)$\e(B")       ; pi~
 262     ("\e$,4*Q)f\e(B" . "\e$,4)%\e(B")       ; mi~
 263     ("\e$,4*R)f\e(B" . "\e$,4)&\e(B")       ; yi~
 264     ("\e$,4*S)f\e(B" . "\e$,4)'\e(B")       ; ri~
 265     ("\e$,4*T)f\e(B" . "\e$,4)(\e(B")       ; li~
 266     ("\e$,4*U)f\e(B" . "\e$,4))\e(B")       ; vi~
 267     ("\e$,4*V)f\e(B" . "\e$,4)*\e(B")       ; l_i~
 268     ("\e$,4*W)f\e(B" . "\e$,4)+\e(B")       ; l.i~
 269     ("\e$,4*X)f\e(B" . "\e$,4),\e(B")       ; r_i~
 270     ("\e$,4*Y)f\e(B" . "\e$,4)-\e(B")       ; n_i~
 271     ("\e$,4*Z)f\e(B" . "\e$,4).\e(B")       ; si~
 272     ("\e$,4*[)f\e(B" . "\e$,4)/\e(B")       ; s'i~
 273     ("\e$,4*\)f\e(B" . "\e$,4)0\e(B")       ; ji~
 274     ("\e$,4*])f\e(B" . "\e$,4)1\e(B")       ; hi~
 275
 276     ("\e$,4*H)g\e(B" . "\e$,4)p\e(B")       ; ku
 277     ("\e$,4*I)g\e(B" . "\e$,4)q\e(B")       ; n^u
 278     ("\e$,4*J)g\e(B" . "\e$,4)r\e(B")       ; cu
 279     ("\e$,4*K)g\e(B" . "\e$,4)s\e(B")       ; n~u
 280     ("\e$,4*L)g\e(B" . "\e$,4)t\e(B")       ; t.u
 281     ("\e$,4*M)g\e(B" . "\e$,4)u\e(B")       ; n.u
 282     ("\e$,4*N)g\e(B" . "\e$,4)v\e(B")       ; tu
 283     ("\e$,4*O)g\e(B" . "\e$,4)x\e(B")       ; nu
 284     ("\e$,4*P)g\e(B" . "\e$,4)y\e(B")       ; pu
 285     ("\e$,4*Q)g\e(B" . "\e$,4)z\e(B")       ; mu
 286     ("\e$,4*R)g\e(B" . "\e$,4){\e(B")       ; yu
 287     ("\e$,4*S)g\e(B" . "\e$,4)|\e(B")       ; ru
 288     ("\e$,4*T)g\e(B" . "\e$,4)}\e(B")       ; lu
 289     ("\e$,4*U)g\e(B" . "\e$,4)~\e(B")       ; vu
 290     ("\e$,4*V)g\e(B" . "\e$,4)\x7f\e(B")       ; l_u
 291     ("\e$,4*W)g\e(B" . "\e$,4* \e(B")       ; l.u
 292     ("\e$,4*X)g\e(B" . "\e$,4*!\e(B")       ; r_u
 293     ("\e$,4*Y)g\e(B" . "\e$,4*"\e(B")       ; n_u
 294
 295     ("\e$,4*H)h\e(B" . "\e$,4*#\e(B")       ; ku~
 296     ("\e$,4*I)h\e(B" . "\e$,4*$\e(B")       ; n^u~
 297     ("\e$,4*J)h\e(B" . "\e$,4*%\e(B")       ; cu~
 298     ("\e$,4*K)h\e(B" . "\e$,4*&\e(B")       ; n~u~
 299     ("\e$,4*L)h\e(B" . "\e$,4*'\e(B")       ; t.u~
 300     ("\e$,4*M)h\e(B" . "\e$,4*(\e(B")       ; n.u~
 301     ("\e$,4*N)h\e(B" . "\e$,4*)\e(B")       ; tu~
 302     ("\e$,4*O)h\e(B" . "\e$,4*+\e(B")       ; nu~
 303     ("\e$,4*P)h\e(B" . "\e$,4*,\e(B")       ; pu~
 304     ("\e$,4*Q)h\e(B" . "\e$,4*-\e(B")       ; mu~
 305     ("\e$,4*R)h\e(B" . "\e$,4*.\e(B")       ; yu~
 306     ("\e$,4*S)h\e(B" . "\e$,4*/\e(B")       ; ru~
 307     ("\e$,4*T)h\e(B" . "\e$,4*6\e(B")       ; lu~
 308     ("\e$,4*U)h\e(B" . "\e$,4*7\e(B")       ; vu~
 309     ("\e$,4*V)h\e(B" . "\e$,4*8\e(B")       ; l_u~
 310     ("\e$,4*W)h\e(B" . "\e$,4*9\e(B")       ; l.u~
 311     ("\e$,4*X)h\e(B" . "\e$,4*:\e(B")       ; r_u~
 312     ("\e$,4*Y)h\e(B" . "\e$,4*;\e(B")       ; n_u~
 313     ))
 314
 315 (defvar tml-glyph-glyph-hash
 316   (let* ((hash (make-hash-table :test 'equal)))
 317     (mapc (function (lambda (x) (puthash (car x) (cdr x) hash)))
 318           tml-glyph-glyph)
 319     hash))
 320
 321 (defvar tml-glyph-glyph-regexp
 322   (tamil-regexp-of-hashtbl-keys tml-glyph-glyph-hash))
 323
 324 (defun tamil-compose-syllable-string (string)
 325   (with-temp-buffer
 326     (insert (decompose-string string))
 327     (tamil-compose-syllable-region (point-min) (point-max))
 328     (buffer-string)))
 329
 330 (defun tamil-compose-syllable-region (from to)
 331   "Compose tamil syllable in region FROM to TO."
 332   (let (glyph-str match-str glyph-reorder-regexps)
 333     (save-excursion
 334       (save-restriction
 335         (narrow-to-region from to)
 336         (goto-char (point-min))
 337         ;; char-glyph-conversion
 338         (while (re-search-forward tml-char-glyph-regexp nil t)
 339           (setq match-str (match-string 0))
 340           (setq glyph-str
 341                 (concat glyph-str (gethash match-str tml-char-glyph-hash))))
 342         ;; glyph reordering
 343         (when (string-match tml-glyph-reorder-key-glyphs glyph-str)
 344           (if (string-match (car tml-glyph-reordering-regexp-list)
 345                             glyph-str)
 346               (setq glyph-str
 347                     (replace-match (cdr tml-glyph-reordering-regexp-list)
 348                                    nil nil glyph-str))))
 349         ;; glyph-glyph-conversion
 350         (when (string-match tml-glyph-glyph-regexp glyph-str)
 351           (setq match-str (match-string 0 glyph-str))
 352           (setq glyph-str
 353                 (replace-match (gethash match-str tml-glyph-glyph-hash)
 354                                nil nil glyph-str)))
 355         ;; concatenate and attach reference-points.
 356         (setq glyph-str
 357               (cdr
 358                (apply
 359                 'nconc
 360                 (mapcar
 361                  (function
 362                   (lambda (x) (list '(5 . 3) x))) ;; default ref. point.
 363                  glyph-str))))
 364         (compose-region from to glyph-str)))))
 365
 366 (provide 'tml-util)
 367
 368 ;;; arch-tag: 4d1c9737-e7b1-44cf-a040-4f64c50e773e
 369 ;;; tml-util.el ends here