lisp/language/china-util.el

   1 ;;; china-util.el --- utilities for Chinese  -*- coding: iso-2022-7bit -*-
   2
   3 ;; Copyright (C) 1995, 2001, 2002, 2003, 2004, 2005, 2006
   4 ;;   Free Software Foundation, Inc.
   5 ;; Copyright (C) 1995, 1997, 2001, 2002, 2003, 2004, 2005, 2006
   6 ;;   National Institute of Advanced Industrial Science and Technology (AIST)
   7 ;;   Registration Number H14PRO021
   8
   9 ;; Keywords: mule, multilingual, Chinese
  10
  11 ;; This file is part of GNU Emacs.
  12
  13 ;; GNU Emacs is free software; you can redistribute it and/or modify
  14 ;; it under the terms of the GNU General Public License as published by
  15 ;; the Free Software Foundation; either version 2, or (at your option)
  16 ;; any later version.
  17
  18 ;; GNU Emacs is distributed in the hope that it will be useful,
  19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ;; GNU General Public License for more details.
  22
  23 ;; You should have received a copy of the GNU General Public License
  24 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  25 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  26 ;; Boston, MA 02110-1301, USA.
  27
  28 ;;; Commentary:
  29
  30 ;;; Code:
  31
  32 ;; Hz/ZW/EUC-TW encoding stuff
  33
  34 ;; HZ is an encoding method for Chinese character set GB2312 used
  35 ;; widely in Internet.  It is very similar to 7-bit environment of
  36 ;; ISO-2022.  The difference is that HZ uses the sequence "~{" and
  37 ;; "~}" for designating GB2312 and ASCII respectively, hence, it
  38 ;; doesn't uses ESC (0x1B) code.
  39
  40 ;; ZW is another encoding method for Chinese character set GB2312.  It
  41 ;; encodes Chinese characters line by line by starting each line with
  42 ;; the sequence "zW".  It also uses only 7-bit as HZ.
  43
  44 ;; EUC-TW is similar to EUC-KS or EUC-JP.  Its main character set is
  45 ;; plane 1 of CNS 11643; characters of planes 2 to 7 are accessed with
  46 ;; a single shift escape followed by three bytes: the first gives the
  47 ;; plane, the second and third the character code.  Note that characters
  48 ;; of plane 1 are (redundantly) accessible with a single shift escape
  49 ;; also.
  50
  51 ;; ISO-2022 escape sequence to designate GB2312.
  52 (defvar iso2022-gb-designation "\e$A")
  53 ;; HZ escape sequence to designate GB2312.
  54 (defvar hz-gb-designnation "~{")
  55 ;; ISO-2022 escape sequence to designate ASCII.
  56 (defvar iso2022-ascii-designation "\e(B")
  57 ;; HZ escape sequence to designate ASCII.
  58 (defvar hz-ascii-designnation "~}")
  59 ;; Regexp of ZW sequence to start GB2312.
  60 (defvar zw-start-gb "^zW")
  61 ;; Regexp for start of GB2312 in an encoding mixture of HZ and ZW.
  62 (defvar hz/zw-start-gb
  63   (concat hz-gb-designnation "\\|" zw-start-gb "\\|[^\0-\177]"))
  64
  65 (defvar decode-hz-line-continuation nil
  66   "Flag to tell if we should care line continuation convention of Hz.")
  67
  68 (defconst hz-set-msb-table
  69   (eval-when-compile
  70     (let ((chars nil)
  71           (i 0))
  72       (while (< i 33)
  73         (push i chars)
  74         (setq i (1+ i)))
  75       (while (< i 127)
  76         (push (+ i 128) chars)
  77         (setq i (1+ i)))
  78       (apply 'string (nreverse chars)))))
  79
  80 ;;;###autoload
  81 (defun decode-hz-region (beg end)
  82   "Decode HZ/ZW encoded text in the current region.
  83 Return the length of resulting text."
  84   (interactive "r")
  85   (save-excursion
  86     (save-restriction
  87       (let (pos ch)
  88         (narrow-to-region beg end)
  89
  90         ;; We, at first, convert HZ/ZW to `euc-china',
  91         ;; then decode it.
  92
  93         ;; "~\n" -> "\n", "~~" -> "~"
  94         (goto-char (point-min))
  95         (while (search-forward "~" nil t)
  96           (setq ch (following-char))
  97           (if (or (= ch ?\n) (= ch ?~)) (delete-char -1)))
  98
  99         ;; "^zW...\n" -> Chinese GB2312
 100         ;; "~{...~}"  -> Chinese GB2312
 101         (goto-char (point-min))
 102         (setq beg nil)
 103         (while (re-search-forward hz/zw-start-gb nil t)
 104           (setq pos (match-beginning 0)
 105                 ch (char-after pos))
 106           ;; Record the first position to start conversion.
 107           (or beg (setq beg pos))
 108           (end-of-line)
 109           (setq end (point))
 110           (if (>= ch 128)               ; 8bit GB2312
 111               nil
 112             (goto-char pos)
 113             (delete-char 2)
 114             (setq end (- end 2))
 115             (if (= ch ?z)                       ; ZW -> euc-china
 116                 (progn
 117                   (translate-region (point) end hz-set-msb-table)
 118                   (goto-char end))
 119               (if (search-forward hz-ascii-designnation
 120                                   (if decode-hz-line-continuation nil end)
 121                                   t)
 122                   (delete-char -2))
 123               (setq end (point))
 124               (translate-region pos (point) hz-set-msb-table))))
 125         (if beg
 126             (decode-coding-region beg end 'euc-china)))
 127       (- (point-max) (point-min)))))
 128
 129 ;;;###autoload
 130 (defun decode-hz-buffer ()
 131   "Decode HZ/ZW encoded text in the current buffer."
 132   (interactive)
 133   (decode-hz-region (point-min) (point-max)))
 134
 135 ;;;###autoload
 136 (defun encode-hz-region (beg end)
 137   "Encode the text in the current region to HZ.
 138 Return the length of resulting text."
 139   (interactive "r")
 140   (save-excursion
 141     (save-restriction
 142       (narrow-to-region beg end)
 143
 144       ;; "~" -> "~~"
 145       (goto-char (point-min))
 146       (while (search-forward "~" nil t) (insert ?~))
 147
 148       ;; Chinese GB2312 -> "~{...~}"
 149       (goto-char (point-min))
 150       (if (re-search-forward "\\cc" nil t)
 151           (let (pos)
 152             (goto-char (setq pos (match-beginning 0)))
 153             (encode-coding-region pos (point-max) 'iso-2022-7bit)
 154             (goto-char pos)
 155             (while (search-forward iso2022-gb-designation nil t)
 156               (delete-char -3)
 157               (insert hz-gb-designnation))
 158             (goto-char pos)
 159             (while (search-forward iso2022-ascii-designation nil t)
 160               (delete-char -3)
 161               (insert hz-ascii-designnation))))
 162       (- (point-max) (point-min)))))
 163
 164 ;;;###autoload
 165 (defun encode-hz-buffer ()
 166   "Encode the text in the current buffer to HZ."
 167   (interactive)
 168   (encode-hz-region (point-min) (point-max)))
 169
 170 ;; The following sets up a translation table (big5-to-cns) from Big 5
 171 ;; to CNS encoding, using some auxiliary functions to make the code
 172 ;; more readable.
 173
 174 ;; Many kudos to Himi!  The used code has been adapted from his
 175 ;; mule-ucs package.
 176
 177 (eval-when-compile
 178 (defun big5-to-flat-code (num)
 179   "Convert NUM in Big 5 encoding to a `flat code'.
 180 0xA140 will be mapped to position 0, 0xA141 to position 1, etc.
 181 There are no gaps in the flat code."
 182
 183   (let ((hi (/ num 256))
 184         (lo (% num 256)))
 185     (+ (* 157 (- hi #xa1))
 186        (- lo (if (>= lo #xa1) 98 64)))))
 187
 188 (defun flat-code-to-big5 (num)
 189   "Convert NUM from a `flat code' to Big 5 encoding.
 190 This is the inverse function of `big5-to-flat-code'."
 191
 192   (let ((hi (/ num 157))
 193         (lo (% num 157)))
 194     (+ (* 256 (+ hi #xa1))
 195        (+ lo (if (< lo 63) 64 98)))))
 196
 197 (defun euc-to-flat-code (num)
 198   "Convert NUM in EUC encoding (in GL representation) to a `flat code'.
 199 0x2121 will be mapped to position 0, 0x2122 to position 1, etc.
 200 There are no gaps in the flat code."
 201
 202   (let ((hi (/ num 256))
 203         (lo (% num 256)))
 204     (+ (* 94 (- hi #x21))
 205        (- lo #x21))))
 206
 207 (defun flat-code-to-euc (num)
 208   "Convert NUM from a `flat code' to EUC encoding (in GL representation).
 209 The inverse function of `euc-to-flat-code'.  The high and low bytes are
 210 returned in a list."
 211
 212   (let ((hi (/ num 94))
 213         (lo (% num 94)))
 214     (list (+ hi #x21) (+ lo #x21))))
 215
 216 (defun expand-euc-big5-alist (alist)
 217   "Create a translation table and fills it with data given in ALIST.
 218 Elements of ALIST can be either given as
 219
 220   ((euc-charset . startchar) . (big5-range-begin . big5-range-end))
 221
 222 or as
 223
 224   (euc-character . big5-charcode)
 225
 226 The former maps a range of glyphs in an EUC charset (where STARTCHAR
 227 is in GL representation) to a certain range of Big 5 encoded
 228 characters, the latter maps a single glyph.  Glyphs which can't be
 229 mapped will be represented with the byte 0xFF.
 230
 231 The return value is the filled translation table."
 232
 233   (let ((chartable (make-char-table 'translation-table #xFF))
 234         char
 235         big5
 236         i
 237         end
 238         codepoint
 239         charset)
 240     (dolist (elem alist)
 241       (setq char (car elem)
 242             big5 (cdr elem))
 243       (cond ((and (consp char)
 244                   (consp big5))
 245              (setq i (big5-to-flat-code (car big5))
 246                    end (big5-to-flat-code (cdr big5))
 247                    codepoint (euc-to-flat-code (cdr char))
 248                    charset (car char))
 249              (while (>= end i)
 250                (aset chartable
 251                      (decode-big5-char (flat-code-to-big5 i))
 252                      (apply (function make-char)
 253                             charset
 254                             (flat-code-to-euc codepoint)))
 255                (setq i (1+ i)
 256                      codepoint (1+ codepoint))))
 257             ((and (char-valid-p char)
 258                   (numberp big5))
 259              (setq i (decode-big5-char big5))
 260              (aset chartable i char))
 261             (t
 262              (error "Unknown slot type: %S" elem))))
 263     ;; the return value
 264     chartable)))
 265
 266 ;; All non-CNS encodings are commented out.
 267
 268 (define-translation-table 'big5-to-cns
 269   (eval-when-compile
 270   (expand-euc-big5-alist
 271    '(
 272      ;; Symbols
 273      ((chinese-cns11643-1 . #x2121) . (#xA140 . #xA1F5))
 274      (?\e$(G"X\e(B . #xA1F6)
 275      (?\e$(G"W\e(B . #xA1F7)
 276      ((chinese-cns11643-1 . #x2259) . (#xA1F8 . #xA2AE))
 277      ((chinese-cns11643-1 . #x2421) . (#xA2AF . #xA3BF))
 278      ;; Control codes (vendor dependent)
 279      ((chinese-cns11643-1 . #x4221) . (#xA3C0 . #xA3E0))
 280      ;; Level 1 Ideographs
 281      ((chinese-cns11643-1 . #x4421) . (#xA440 . #xACFD))
 282      (?\e$(GWS\e(B . #xACFE)
 283      ((chinese-cns11643-1 . #x5323) . (#xAD40 . #xAFCF))
 284      ((chinese-cns11643-1 . #x5754) . (#xAFD0 . #xBBC7))
 285      ((chinese-cns11643-1 . #x6B51) . (#xBBC8 . #xBE51))
 286      (?\e$(GkP\e(B . #xBE52)
 287      ((chinese-cns11643-1 . #x6F5C) . (#xBE53 . #xC1AA))
 288      ((chinese-cns11643-1 . #x7536) . (#xC1AB . #xC2CA))
 289      (?\e$(Gu5\e(B . #xC2CB)
 290      ((chinese-cns11643-1 . #x7737) . (#xC2CC . #xC360))
 291      ((chinese-cns11643-1 . #x782E) . (#xC361 . #xC3B8))
 292      (?\e$(Gxe\e(B . #xC3B9)
 293      (?\e$(Gxd\e(B . #xC3BA)
 294      ((chinese-cns11643-1 . #x7866) . (#xC3BB . #xC455))
 295      (?\e$(Gx-\e(B . #xC456)
 296      ((chinese-cns11643-1 . #x7962) . (#xC457 . #xC67E))
 297      ;; Symbols
 298      ((chinese-cns11643-1 . #x2621) . (#xC6A1 . #xC6BE))
 299      ;; Radicals
 300      (?\e$(G'#\e(B . #xC6BF)
 301      (?\e$(G'$\e(B . #xC6C0)
 302      (?\e$(G'&\e(B . #xC6C1)
 303      (?\e$(G'(\e(B . #xC6C2)
 304      (?\e$(G'-\e(B . #xC6C3)
 305      (?\e$(G'.\e(B . #xC6C4)
 306      (?\e$(G'/\e(B . #xC6C5)
 307      (?\e$(G'4\e(B . #xC6C6)
 308      (?\e$(G'7\e(B . #xC6C7)
 309      (?\e$(G':\e(B . #xC6C8)
 310      (?\e$(G'<\e(B . #xC6C9)
 311      (?\e$(G'B\e(B . #xC6CA)
 312      (?\e$(G'G\e(B . #xC6CB)
 313      (?\e$(G'N\e(B . #xC6CC)
 314      (?\e$(G'S\e(B . #xC6CD)
 315      (?\e$(G'T\e(B . #xC6CE)
 316      (?\e$(G'U\e(B . #xC6CF)
 317      (?\e$(G'Y\e(B . #xC6D0)
 318      (?\e$(G'Z\e(B . #xC6D1)
 319      (?\e$(G'a\e(B . #xC6D2)
 320      (?\e$(G'f\e(B . #xC6D3)
 321      (?\e$(G()\e(B . #xC6D4)
 322      (?\e$(G(*\e(B . #xC6D5)
 323      (?\e$(G(c\e(B . #xC6D6)
 324      (?\e$(G(l\e(B . #xC6D7)
 325      ;; Diacritical Marks
 326      ; ((japanese-jisx0208 . #x212F) . (#xC6D8 . #xC6D9))
 327      ;; Japanese Kana Supplement
 328      ; ((japanese-jisx0208 . #x2133) . (#xC6DA . #xC6E3))
 329      ;; Japanese Hiragana
 330      ; ((japanese-jisx0208 . #x2421) . (#xC6E7 . #xC77A))
 331      ;; Japanese Katakana
 332      ; ((japanese-jisx0208 . #x2521) . (#xC77B . #xC7F2))
 333      ;; Cyrillic Characters
 334      ; ((japanese-jisx0208 . #x2721) . (#xC7F3 . #xC854))
 335      ; ((japanese-jisx0208 . #x2751) . (#xC855 . #xC875))
 336      ;; Special Chinese Characters
 337      (?\e$(J!#\e(B . #xC879)
 338      (?\e$(J!$\e(B . #xC87B)
 339      (?\e$(J!*\e(B . #xC87D)
 340      (?\e$(J!R\e(B . #xC8A2)
 341
 342      ;; JIS X 0208 NOT SIGN (cf. U+00AC)
 343      ; (?\e$B"L\e(B . #xC8CD)
 344      ;; JIS X 0212 BROKEN BAR (cf. U+00A6)
 345      ; (?\e$(D"C\e(B . #xC8CE)
 346
 347      ;; GB 2312 characters
 348      ; (?\e$A!d\e(B . #xC8CF)
 349      ; (?\e$A!e\e(B . #xC8D0)
 350         ;;;;; C8D1 - Japanese `(\e$B3t\e(B)'
 351      ; (?\e$A!m\e(B . #xC8D2)
 352         ;;;;; C8D2 - Tel.
 353
 354      ;; Level 2 Ideographs
 355      ((chinese-cns11643-2 . #x2121) . (#xC940 . #xC949))
 356      (?\e$(GDB\e(B . #xC94A);; a duplicate of #xA461
 357      ((chinese-cns11643-2 . #x212B) . (#xC94B . #xC96B))
 358      ((chinese-cns11643-2 . #x214D) . (#xC96C . #xC9BD))
 359      (?\e$(H!L\e(B . #xC9BE)
 360      ((chinese-cns11643-2 . #x217D) . (#xC9BF . #xC9EC))
 361      ((chinese-cns11643-2 . #x224E) . (#xC9ED . #xCAF6))
 362      (?\e$(H"M\e(B . #xCAF7)
 363      ((chinese-cns11643-2 . #x2439) . (#xCAF8 . #xD6CB))
 364      (?\e$(H>c\e(B . #xD6CC)
 365      ((chinese-cns11643-2 . #x3770) . (#xD6CD . #xD779))
 366      (?\e$(H?j\e(B . #xD77A)
 367      ((chinese-cns11643-2 . #x387E) . (#xD77B . #xDADE))
 368      (?\e$(H7o\e(B . #xDADF)
 369      ((chinese-cns11643-2 . #x3E64) . (#xDAE0 . #xDBA6))
 370      ((chinese-cns11643-2 . #x3F6B) . (#xDBA7 . #xDDFB))
 371      (?\e$(HAv\e(B . #xDDFC);; a duplicate of #xDCD1
 372      ((chinese-cns11643-2 . #x4424) . (#xDDFD . #xE8A2))
 373      ((chinese-cns11643-2 . #x554C) . (#xE8A3 . #xE975))
 374      ((chinese-cns11643-2 . #x5723) . (#xE976 . #xEB5A))
 375      ((chinese-cns11643-2 . #x5A29) . (#xEB5B . #xEBF0))
 376      (?\e$(HUK\e(B . #xEBF1)
 377      ((chinese-cns11643-2 . #x5B3F) . (#xEBF2 . #xECDD))
 378      (?\e$(HW"\e(B . #xECDE)
 379      ((chinese-cns11643-2 . #x5C6A) . (#xECDF . #xEDA9))
 380      ((chinese-cns11643-2 . #x5D75) . (#xEDAA . #xEEEA))
 381      (?\e$(Hd/\e(B . #xEEEB)
 382      ((chinese-cns11643-2 . #x6039) . (#xEEEC . #xF055))
 383      (?\e$(H]t\e(B . #xF056)
 384      ((chinese-cns11643-2 . #x6243) . (#xF057 . #xF0CA))
 385      (?\e$(HZ(\e(B . #xF0CB)
 386      ((chinese-cns11643-2 . #x6337) . (#xF0CC . #xF162))
 387      ((chinese-cns11643-2 . #x6430) . (#xF163 . #xF16A))
 388      (?\e$(Hga\e(B . #xF16B)
 389      ((chinese-cns11643-2 . #x6438) . (#xF16C . #xF267))
 390      (?\e$(Hi4\e(B . #xF268)
 391      ((chinese-cns11643-2 . #x6573) . (#xF269 . #xF2C2))
 392      ((chinese-cns11643-2 . #x664E) . (#xF2C3 . #xF374))
 393      ((chinese-cns11643-2 . #x6762) . (#xF375 . #xF465))
 394      ((chinese-cns11643-2 . #x6935) . (#xF466 . #xF4B4))
 395      (?\e$(HfM\e(B . #xF4B5)
 396      ((chinese-cns11643-2 . #x6962) . (#xF4B6 . #xF4FC))
 397      ((chinese-cns11643-2 . #x6A4C) . (#xF4FD . #xF662))
 398      (?\e$(HjK\e(B . #xF663)
 399      ((chinese-cns11643-2 . #x6C52) . (#xF664 . #xF976))
 400      ((chinese-cns11643-2 . #x7167) . (#xF977 . #xF9C3))
 401      (?\e$(Hqf\e(B . #xF9C4)
 402      (?\e$(Hr4\e(B . #xF9C5)
 403      (?\e$(Hr@\e(B . #xF9C6)
 404      ((chinese-cns11643-2 . #x7235) . (#xF9C7 . #xF9D1))
 405      ((chinese-cns11643-2 . #x7241) . (#xF9D2 . #xF9D5))
 406
 407      ;; Additional Ideographs
 408      (?\e$(IC7\e(B . #xF9D6)
 409      (?\e$(IOP\e(B . #xF9D7)
 410      (?\e$(IDN\e(B . #xF9D8)
 411      (?\e$(IPJ\e(B . #xF9D9)
 412      (?\e$(I,]\e(B . #xF9DA)
 413      (?\e$(I=~\e(B . #xF9DB)
 414      (?\e$(IK\\e(B . #xF9DC)
 415     )
 416   ))
 417 )
 418
 419 ;;
 420 (provide 'china-util)
 421
 422 ;;; arch-tag: 5a47b084-b9ac-420e-8191-70c5b3a14836
 423 ;;; china-util.el ends here