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, 2007
   4 ;;   Free Software Foundation, Inc.
   5 ;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   6 ;;   2005, 2006, 2007
   7 ;;   National Institute of Advanced Industrial Science and Technology (AIST)
   8 ;;   Registration Number H14PRO021
   9
  10 ;; Keywords: mule, multilingual, Chinese
  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 3, 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 ;;; Commentary:
  30
  31 ;;; Code:
  32
  33 ;; Hz/ZW/EUC-TW encoding stuff
  34
  35 ;; HZ is an encoding method for Chinese character set GB2312 used
  36 ;; widely in Internet.  It is very similar to 7-bit environment of
  37 ;; ISO-2022.  The difference is that HZ uses the sequence "~{" and
  38 ;; "~}" for designating GB2312 and ASCII respectively, hence, it
  39 ;; doesn't uses ESC (0x1B) code.
  40
  41 ;; ZW is another encoding method for Chinese character set GB2312.  It
  42 ;; encodes Chinese characters line by line by starting each line with
  43 ;; the sequence "zW".  It also uses only 7-bit as HZ.
  44
  45 ;; EUC-TW is similar to EUC-KS or EUC-JP.  Its main character set is
  46 ;; plane 1 of CNS 11643; characters of planes 2 to 7 are accessed with
  47 ;; a single shift escape followed by three bytes: the first gives the
  48 ;; plane, the second and third the character code.  Note that characters
  49 ;; of plane 1 are (redundantly) accessible with a single shift escape
  50 ;; also.
  51
  52 ;; ISO-2022 escape sequence to designate GB2312.
  53 (defvar iso2022-gb-designation "\e$A")
  54 ;; HZ escape sequence to designate GB2312.
  55 (defvar hz-gb-designnation "~{")
  56 ;; ISO-2022 escape sequence to designate ASCII.
  57 (defvar iso2022-ascii-designation "\e(B")
  58 ;; HZ escape sequence to designate ASCII.
  59 (defvar hz-ascii-designnation "~}")
  60 ;; Regexp of ZW sequence to start GB2312.
  61 (defvar zw-start-gb "^zW")
  62 ;; Regexp for start of GB2312 in an encoding mixture of HZ and ZW.
  63 (defvar hz/zw-start-gb
  64   (concat hz-gb-designnation "\\|" zw-start-gb "\\|[^\0-\177]"))
  65
  66 (defvar decode-hz-line-continuation nil
  67   "Flag to tell if we should care line continuation convention of Hz.")
  68
  69 (defconst hz-set-msb-table
  70   (eval-when-compile
  71     (let ((chars nil)
  72           (i 0))
  73       (while (< i 33)
  74         (push i chars)
  75         (setq i (1+ i)))
  76       (while (< i 127)
  77         (push (+ i 128) chars)
  78         (setq i (1+ i)))
  79       (apply 'string (nreverse chars)))))
  80
  81 ;;;###autoload
  82 (defun decode-hz-region (beg end)
  83   "Decode HZ/ZW encoded text in the current region.
  84 Return the length of resulting text."
  85   (interactive "r")
  86   (save-excursion
  87     (save-restriction
  88       (let (pos ch)
  89         (narrow-to-region beg end)
  90
  91         ;; We, at first, convert HZ/ZW to `euc-china',
  92         ;; then decode it.
  93
  94         ;; "~\n" -> "\n", "~~" -> "~"
  95         (goto-char (point-min))
  96         (while (search-forward "~" nil t)
  97           (setq ch (following-char))
  98           (if (or (= ch ?\n) (= ch ?~)) (delete-char -1)))
  99
 100         ;; "^zW...\n" -> Chinese GB2312
 101         ;; "~{...~}"  -> Chinese GB2312
 102         (goto-char (point-min))
 103         (setq beg nil)
 104         (while (re-search-forward hz/zw-start-gb nil t)
 105           (setq pos (match-beginning 0)
 106                 ch (char-after pos))
 107           ;; Record the first position to start conversion.
 108           (or beg (setq beg pos))
 109           (end-of-line)
 110           (setq end (point))
 111           (if (>= ch 128)               ; 8bit GB2312
 112               nil
 113             (goto-char pos)
 114             (delete-char 2)
 115             (setq end (- end 2))
 116             (if (= ch ?z)                       ; ZW -> euc-china
 117                 (progn
 118                   (translate-region (point) end hz-set-msb-table)
 119                   (goto-char end))
 120               (if (search-forward hz-ascii-designnation
 121                                   (if decode-hz-line-continuation nil end)
 122                                   t)
 123                   (delete-char -2))
 124               (setq end (point))
 125               (translate-region pos (point) hz-set-msb-table))))
 126         (if beg
 127             (decode-coding-region beg end 'euc-china)))
 128       (- (point-max) (point-min)))))
 129
 130 ;;;###autoload
 131 (defun decode-hz-buffer ()
 132   "Decode HZ/ZW encoded text in the current buffer."
 133   (interactive)
 134   (decode-hz-region (point-min) (point-max)))
 135
 136 ;;;###autoload
 137 (defun encode-hz-region (beg end)
 138   "Encode the text in the current region to HZ.
 139 Return the length of resulting text."
 140   (interactive "r")
 141   (save-excursion
 142     (save-restriction
 143       (narrow-to-region beg end)
 144
 145       ;; "~" -> "~~"
 146       (goto-char (point-min))
 147       (while (search-forward "~" nil t) (insert ?~))
 148
 149       ;; Chinese GB2312 -> "~{...~}"
 150       (goto-char (point-min))
 151       (if (re-search-forward "\\cc" nil t)
 152           (let (pos)
 153             (goto-char (setq pos (match-beginning 0)))
 154             (encode-coding-region pos (point-max) 'iso-2022-7bit)
 155             (goto-char pos)
 156             (while (search-forward iso2022-gb-designation nil t)
 157               (delete-char -3)
 158               (insert hz-gb-designnation))
 159             (goto-char pos)
 160             (while (search-forward iso2022-ascii-designation nil t)
 161               (delete-char -3)
 162               (insert hz-ascii-designnation))))
 163       (- (point-max) (point-min)))))
 164
 165 ;;;###autoload
 166 (defun encode-hz-buffer ()
 167   "Encode the text in the current buffer to HZ."
 168   (interactive)
 169   (encode-hz-region (point-min) (point-max)))
 170
 171 ;; The following sets up a translation table (big5-to-cns) from Big 5
 172 ;; to CNS encoding, using some auxiliary functions to make the code
 173 ;; more readable.
 174
 175 ;; Many kudos to Himi!  The used code has been adapted from his
 176 ;; mule-ucs package.
 177
 178 (eval-when-compile
 179 (defun big5-to-flat-code (num)
 180   "Convert NUM in Big 5 encoding to a `flat code'.
 181 0xA140 will be mapped to position 0, 0xA141 to position 1, etc.
 182 There are no gaps in the flat code."
 183
 184   (let ((hi (/ num 256))
 185         (lo (% num 256)))
 186     (+ (* 157 (- hi #xa1))
 187        (- lo (if (>= lo #xa1) 98 64)))))
 188
 189 (defun flat-code-to-big5 (num)
 190   "Convert NUM from a `flat code' to Big 5 encoding.
 191 This is the inverse function of `big5-to-flat-code'."
 192
 193   (let ((hi (/ num 157))
 194         (lo (% num 157)))
 195     (+ (* 256 (+ hi #xa1))
 196        (+ lo (if (< lo 63) 64 98)))))
 197
 198 (defun euc-to-flat-code (num)
 199   "Convert NUM in EUC encoding (in GL representation) to a `flat code'.
 200 0x2121 will be mapped to position 0, 0x2122 to position 1, etc.
 201 There are no gaps in the flat code."
 202
 203   (let ((hi (/ num 256))
 204         (lo (% num 256)))
 205     (+ (* 94 (- hi #x21))
 206        (- lo #x21))))
 207
 208 (defun flat-code-to-euc (num)
 209   "Convert NUM from a `flat code' to EUC encoding (in GL representation).
 210 The inverse function of `euc-to-flat-code'.  The high and low bytes are
 211 returned in a list."
 212
 213   (let ((hi (/ num 94))
 214         (lo (% num 94)))
 215     (list (+ hi #x21) (+ lo #x21))))
 216
 217 (defun expand-euc-big5-alist (alist)
 218   "Create a translation table and fills it with data given in ALIST.
 219 Elements of ALIST can be either given as
 220
 221   ((euc-charset . startchar) . (big5-range-begin . big5-range-end))
 222
 223 or as
 224
 225   (euc-character . big5-charcode)
 226
 227 The former maps a range of glyphs in an EUC charset (where STARTCHAR
 228 is in GL representation) to a certain range of Big 5 encoded
 229 characters, the latter maps a single glyph.  Glyphs which can't be
 230 mapped will be represented with the byte 0xFF.
 231
 232 The return value is the filled translation table."
 233
 234   (let ((chartable (make-char-table 'translation-table #xFF))
 235         char
 236         big5
 237         i
 238         end
 239         codepoint
 240         charset)
 241     (dolist (elem alist)
 242       (setq char (car elem)
 243             big5 (cdr elem))
 244       (cond ((and (consp char)
 245                   (consp big5))
 246              (setq i (big5-to-flat-code (car big5))
 247                    end (big5-to-flat-code (cdr big5))
 248                    codepoint (euc-to-flat-code (cdr char))
 249                    charset (car char))
 250              (while (>= end i)
 251                (aset chartable
 252                      (decode-big5-char (flat-code-to-big5 i))
 253                      (apply (function make-char)
 254                             charset
 255                             (flat-code-to-euc codepoint)))
 256                (setq i (1+ i)
 257                      codepoint (1+ codepoint))))
 258             ((and (char-valid-p char)
 259                   (numberp big5))
 260              (setq i (decode-big5-char big5))
 261              (aset chartable i char))
 262             (t
 263              (error "Unknown slot type: %S" elem))))
 264     ;; the return value
 265     chartable)))
 266
 267 ;; All non-CNS encodings are commented out.
 268
 269 (define-translation-table 'big5-to-cns
 270   (eval-when-compile
 271   (expand-euc-big5-alist
 272    '(
 273      ;; Symbols
 274      ((chinese-cns11643-1 . #x2121) . (#xA140 . #xA1F5))
 275      (?\e$(G"X\e(B . #xA1F6)
 276      (?\e$(G"W\e(B . #xA1F7)
 277      ((chinese-cns11643-1 . #x2259) . (#xA1F8 . #xA2AE))
 278      ((chinese-cns11643-1 . #x2421) . (#xA2AF . #xA3BF))
 279      ;; Control codes (vendor dependent)
 280      ((chinese-cns11643-1 . #x4221) . (#xA3C0 . #xA3E0))
 281      ;; Level 1 Ideographs
 282      ((chinese-cns11643-1 . #x4421) . (#xA440 . #xACFD))
 283      (?\e$(GWS\e(B . #xACFE)
 284      ((chinese-cns11643-1 . #x5323) . (#xAD40 . #xAFCF))
 285      ((chinese-cns11643-1 . #x5754) . (#xAFD0 . #xBBC7))
 286      ((chinese-cns11643-1 . #x6B51) . (#xBBC8 . #xBE51))
 287      (?\e$(GkP\e(B . #xBE52)
 288      ((chinese-cns11643-1 . #x6F5C) . (#xBE53 . #xC1AA))
 289      ((chinese-cns11643-1 . #x7536) . (#xC1AB . #xC2CA))
 290      (?\e$(Gu5\e(B . #xC2CB)
 291      ((chinese-cns11643-1 . #x7737) . (#xC2CC . #xC360))
 292      ((chinese-cns11643-1 . #x782E) . (#xC361 . #xC3B8))
 293      (?\e$(Gxe\e(B . #xC3B9)
 294      (?\e$(Gxd\e(B . #xC3BA)
 295      ((chinese-cns11643-1 . #x7866) . (#xC3BB . #xC455))
 296      (?\e$(Gx-\e(B . #xC456)
 297      ((chinese-cns11643-1 . #x7962) . (#xC457 . #xC67E))
 298      ;; Symbols
 299      ((chinese-cns11643-1 . #x2621) . (#xC6A1 . #xC6BE))
 300      ;; Radicals
 301      (?\e$(G'#\e(B . #xC6BF)
 302      (?\e$(G'$\e(B . #xC6C0)
 303      (?\e$(G'&\e(B . #xC6C1)
 304      (?\e$(G'(\e(B . #xC6C2)
 305      (?\e$(G'-\e(B . #xC6C3)
 306      (?\e$(G'.\e(B . #xC6C4)
 307      (?\e$(G'/\e(B . #xC6C5)
 308      (?\e$(G'4\e(B . #xC6C6)
 309      (?\e$(G'7\e(B . #xC6C7)
 310      (?\e$(G':\e(B . #xC6C8)
 311      (?\e$(G'<\e(B . #xC6C9)
 312      (?\e$(G'B\e(B . #xC6CA)
 313      (?\e$(G'G\e(B . #xC6CB)
 314      (?\e$(G'N\e(B . #xC6CC)
 315      (?\e$(G'S\e(B . #xC6CD)
 316      (?\e$(G'T\e(B . #xC6CE)
 317      (?\e$(G'U\e(B . #xC6CF)
 318      (?\e$(G'Y\e(B . #xC6D0)
 319      (?\e$(G'Z\e(B . #xC6D1)
 320      (?\e$(G'a\e(B . #xC6D2)
 321      (?\e$(G'f\e(B . #xC6D3)
 322      (?\e$(G()\e(B . #xC6D4)
 323      (?\e$(G(*\e(B . #xC6D5)
 324      (?\e$(G(c\e(B . #xC6D6)
 325      (?\e$(G(l\e(B . #xC6D7)
 326      ;; Diacritical Marks
 327      ; ((japanese-jisx0208 . #x212F) . (#xC6D8 . #xC6D9))
 328      ;; Japanese Kana Supplement
 329      ; ((japanese-jisx0208 . #x2133) . (#xC6DA . #xC6E3))
 330      ;; Japanese Hiragana
 331      ; ((japanese-jisx0208 . #x2421) . (#xC6E7 . #xC77A))
 332      ;; Japanese Katakana
 333      ; ((japanese-jisx0208 . #x2521) . (#xC77B . #xC7F2))
 334      ;; Cyrillic Characters
 335      ; ((japanese-jisx0208 . #x2721) . (#xC7F3 . #xC854))
 336      ; ((japanese-jisx0208 . #x2751) . (#xC855 . #xC875))
 337      ;; Special Chinese Characters
 338      (?\e$(J!#\e(B . #xC879)
 339      (?\e$(J!$\e(B . #xC87B)
 340      (?\e$(J!*\e(B . #xC87D)
 341      (?\e$(J!R\e(B . #xC8A2)
 342
 343      ;; JIS X 0208 NOT SIGN (cf. U+00AC)
 344      ; (?\e$B"L\e(B . #xC8CD)
 345      ;; JIS X 0212 BROKEN BAR (cf. U+00A6)
 346      ; (?\e$(D"C\e(B . #xC8CE)
 347
 348      ;; GB 2312 characters
 349      ; (?\e$A!d\e(B . #xC8CF)
 350      ; (?\e$A!e\e(B . #xC8D0)
 351         ;;;;; C8D1 - Japanese `(\e$B3t\e(B)'
 352      ; (?\e$A!m\e(B . #xC8D2)
 353         ;;;;; C8D2 - Tel.
 354
 355      ;; Level 2 Ideographs
 356      ((chinese-cns11643-2 . #x2121) . (#xC940 . #xC949))
 357      (?\e$(GDB\e(B . #xC94A);; a duplicate of #xA461
 358      ((chinese-cns11643-2 . #x212B) . (#xC94B . #xC96B))
 359      ((chinese-cns11643-2 . #x214D) . (#xC96C . #xC9BD))
 360      (?\e$(H!L\e(B . #xC9BE)
 361      ((chinese-cns11643-2 . #x217D) . (#xC9BF . #xC9EC))
 362      ((chinese-cns11643-2 . #x224E) . (#xC9ED . #xCAF6))
 363      (?\e$(H"M\e(B . #xCAF7)
 364      ((chinese-cns11643-2 . #x2439) . (#xCAF8 . #xD6CB))
 365      (?\e$(H>c\e(B . #xD6CC)
 366      ((chinese-cns11643-2 . #x3770) . (#xD6CD . #xD779))
 367      (?\e$(H?j\e(B . #xD77A)
 368      ((chinese-cns11643-2 . #x387E) . (#xD77B . #xDADE))
 369      (?\e$(H7o\e(B . #xDADF)
 370      ((chinese-cns11643-2 . #x3E64) . (#xDAE0 . #xDBA6))
 371      ((chinese-cns11643-2 . #x3F6B) . (#xDBA7 . #xDDFB))
 372      (?\e$(HAv\e(B . #xDDFC);; a duplicate of #xDCD1
 373      ((chinese-cns11643-2 . #x4424) . (#xDDFD . #xE8A2))
 374      ((chinese-cns11643-2 . #x554C) . (#xE8A3 . #xE975))
 375      ((chinese-cns11643-2 . #x5723) . (#xE976 . #xEB5A))
 376      ((chinese-cns11643-2 . #x5A29) . (#xEB5B . #xEBF0))
 377      (?\e$(HUK\e(B . #xEBF1)
 378      ((chinese-cns11643-2 . #x5B3F) . (#xEBF2 . #xECDD))
 379      (?\e$(HW"\e(B . #xECDE)
 380      ((chinese-cns11643-2 . #x5C6A) . (#xECDF . #xEDA9))
 381      ((chinese-cns11643-2 . #x5D75) . (#xEDAA . #xEEEA))
 382      (?\e$(Hd/\e(B . #xEEEB)
 383      ((chinese-cns11643-2 . #x6039) . (#xEEEC . #xF055))
 384      (?\e$(H]t\e(B . #xF056)
 385      ((chinese-cns11643-2 . #x6243) . (#xF057 . #xF0CA))
 386      (?\e$(HZ(\e(B . #xF0CB)
 387      ((chinese-cns11643-2 . #x6337) . (#xF0CC . #xF162))
 388      ((chinese-cns11643-2 . #x6430) . (#xF163 . #xF16A))
 389      (?\e$(Hga\e(B . #xF16B)
 390      ((chinese-cns11643-2 . #x6438) . (#xF16C . #xF267))
 391      (?\e$(Hi4\e(B . #xF268)
 392      ((chinese-cns11643-2 . #x6573) . (#xF269 . #xF2C2))
 393      ((chinese-cns11643-2 . #x664E) . (#xF2C3 . #xF374))
 394      ((chinese-cns11643-2 . #x6762) . (#xF375 . #xF465))
 395      ((chinese-cns11643-2 . #x6935) . (#xF466 . #xF4B4))
 396      (?\e$(HfM\e(B . #xF4B5)
 397      ((chinese-cns11643-2 . #x6962) . (#xF4B6 . #xF4FC))
 398      ((chinese-cns11643-2 . #x6A4C) . (#xF4FD . #xF662))
 399      (?\e$(HjK\e(B . #xF663)
 400      ((chinese-cns11643-2 . #x6C52) . (#xF664 . #xF976))
 401      ((chinese-cns11643-2 . #x7167) . (#xF977 . #xF9C3))
 402      (?\e$(Hqf\e(B . #xF9C4)
 403      (?\e$(Hr4\e(B . #xF9C5)
 404      (?\e$(Hr@\e(B . #xF9C6)
 405      ((chinese-cns11643-2 . #x7235) . (#xF9C7 . #xF9D1))
 406      ((chinese-cns11643-2 . #x7241) . (#xF9D2 . #xF9D5))
 407
 408      ;; Additional Ideographs
 409      (?\e$(IC7\e(B . #xF9D6)
 410      (?\e$(IOP\e(B . #xF9D7)
 411      (?\e$(IDN\e(B . #xF9D8)
 412      (?\e$(IPJ\e(B . #xF9D9)
 413      (?\e$(I,]\e(B . #xF9DA)
 414      (?\e$(I=~\e(B . #xF9DB)
 415      (?\e$(IK\\e(B . #xF9DC)
 416     )
 417   ))
 418 )
 419
 420 ;;
 421 (provide 'china-util)
 422
 423 ;;; arch-tag: 5a47b084-b9ac-420e-8191-70c5b3a14836
 424 ;;; china-util.el ends here