code.delx.au - gnu-emacs/blob - lisp/language/china-util.el

   1 ;;; china-util.el --- utilities for Chinese  -*- coding: iso-2022-7bit -*-
   2
   3 ;; Copyright (C) 1995, 2003 Electrotechnical Laboratory, JAPAN.
   4 ;; Licensed to the Free Software Foundation.
   5 ;; Copyright (C) 1995, 2001 Free Software Foundation, Inc.
   6
   7 ;; Keywords: mule, multilingual, Chinese
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Commentary:
  27
  28 ;;; Code:
  29
  30 ;; Hz/ZW/EUC-TW encoding stuff
  31
  32 ;; HZ is an encoding method for Chinese character set GB2312 used
  33 ;; widely in Internet.  It is very similar to 7-bit environment of
  34 ;; ISO-2022.  The difference is that HZ uses the sequence "~{" and
  35 ;; "~}" for designating GB2312 and ASCII respectively, hence, it
  36 ;; doesn't uses ESC (0x1B) code.
  37
  38 ;; ZW is another encoding method for Chinese character set GB2312.  It
  39 ;; encodes Chinese characters line by line by starting each line with
  40 ;; the sequence "zW".  It also uses only 7-bit as HZ.
  41
  42 ;; EUC-TW is similar to EUC-KS or EUC-JP.  Its main character set is
  43 ;; plane 1 of CNS 11643; characters of planes 2 to 7 are accessed with
  44 ;; a single shift escape followed by three bytes: the first gives the
  45 ;; plane, the second and third the character code.  Note that characters
  46 ;; of plane 1 are (redundantly) accessible with a single shift escape
  47 ;; also.
  48
  49 ;; ISO-2022 escape sequence to designate GB2312.
  50 (defvar iso2022-gb-designation "\e$A")
  51 ;; HZ escape sequence to designate GB2312.
  52 (defvar hz-gb-designnation "~{")
  53 ;; ISO-2022 escape sequence to designate ASCII.
  54 (defvar iso2022-ascii-designation "\e(B")
  55 ;; HZ escape sequence to designate ASCII.
  56 (defvar hz-ascii-designnation "~}")
  57 ;; Regexp of ZW sequence to start GB2312.
  58 (defvar zw-start-gb "^zW")
  59 ;; Regexp for start of GB2312 in an encoding mixture of HZ and ZW.
  60 (defvar hz/zw-start-gb
  61   (concat hz-gb-designnation "\\|" zw-start-gb "\\|[^\0-\177]"))
  62
  63 (defvar decode-hz-line-continuation nil
  64   "Flag to tell if we should care line continuation convention of Hz.")
  65
  66 (defconst hz-set-msb-table
  67   (eval-when-compile
  68     (let ((chars nil)
  69           (i 0))
  70       (while (< i 33)
  71         (push i chars)
  72         (setq i (1+ i)))
  73       (while (< i 127)
  74         (push (+ i 128) chars)
  75         (setq i (1+ i)))
  76       (apply 'string (nreverse chars)))))
  77
  78 ;;;###autoload
  79 (defun decode-hz-region (beg end)
  80   "Decode HZ/ZW encoded text in the current region.
  81 Return the length of resulting text."
  82   (interactive "r")
  83   (save-excursion
  84     (save-restriction
  85       (let (pos ch)
  86         (narrow-to-region beg end)
  87
  88         ;; We, at first, convert HZ/ZW to `euc-china',
  89         ;; then decode it.
  90
  91         ;; "~\n" -> "\n", "~~" -> "~"
  92         (goto-char (point-min))
  93         (while (search-forward "~" nil t)
  94           (setq ch (following-char))
  95           (if (or (= ch ?\n) (= ch ?~)) (delete-char -1)))
  96
  97         ;; "^zW...\n" -> Chinese GB2312
  98         ;; "~{...~}"  -> Chinese GB2312
  99         (goto-char (point-min))
 100         (setq beg nil)
 101         (while (re-search-forward hz/zw-start-gb nil t)
 102           (setq pos (match-beginning 0)
 103                 ch (char-after pos))
 104           ;; Record the first position to start conversion.
 105           (or beg (setq beg pos))
 106           (end-of-line)
 107           (setq end (point))
 108           (if (>= ch 128)               ; 8bit GB2312
 109               nil
 110             (goto-char pos)
 111             (delete-char 2)
 112             (setq end (- end 2))
 113             (if (= ch ?z)                       ; ZW -> euc-china
 114                 (progn
 115                   (translate-region (point) end hz-set-msb-table)
 116                   (goto-char end))
 117               (if (search-forward hz-ascii-designnation
 118                                   (if decode-hz-line-continuation nil end)
 119                                   t)
 120                   (delete-char -2))
 121               (setq end (point))
 122               (translate-region pos (point) hz-set-msb-table))))
 123         (if beg
 124             (decode-coding-region beg end 'euc-china)))
 125       (- (point-max) (point-min)))))
 126
 127 ;;;###autoload
 128 (defun decode-hz-buffer ()
 129   "Decode HZ/ZW encoded text in the current buffer."
 130   (interactive)
 131   (decode-hz-region (point-min) (point-max)))
 132
 133 ;;;###autoload
 134 (defun encode-hz-region (beg end)
 135   "Encode the text in the current region to HZ.
 136 Return the length of resulting text."
 137   (interactive "r")
 138   (save-excursion
 139     (save-restriction
 140       (narrow-to-region beg end)
 141
 142       ;; "~" -> "~~"
 143       (goto-char (point-min))
 144       (while (search-forward "~" nil t) (insert ?~))
 145
 146       ;; Chinese GB2312 -> "~{...~}"
 147       (goto-char (point-min))
 148       (if (re-search-forward "\\cc" nil t)
 149           (let (pos)
 150             (goto-char (setq pos (match-beginning 0)))
 151             (encode-coding-region pos (point-max) 'iso-2022-7bit)
 152             (goto-char pos)
 153             (while (search-forward iso2022-gb-designation nil t)
 154               (delete-char -3)
 155               (insert hz-gb-designnation))
 156             (goto-char pos)
 157             (while (search-forward iso2022-ascii-designation nil t)
 158               (delete-char -3)
 159               (insert hz-ascii-designnation))))
 160       (- (point-max) (point-min)))))
 161
 162 ;;;###autoload
 163 (defun encode-hz-buffer ()
 164   "Encode the text in the current buffer to HZ."
 165   (interactive)
 166   (encode-hz-region (point-min) (point-max)))
 167
 168 ;; The following sets up a translation table (big5-to-cns) from Big 5
 169 ;; to CNS encoding, using some auxiliary functions to make the code
 170 ;; more readable.
 171
 172 ;; Many kudos to Himi!  The used code has been adapted from his
 173 ;; mule-ucs package.
 174
 175 (eval-when-compile
 176 (defun big5-to-flat-code (num)
 177   "Convert NUM in Big 5 encoding to a `flat code'.
 178 0xA140 will be mapped to position 0, 0xA141 to position 1, etc.
 179 There are no gaps in the flat code."
 180
 181   (let ((hi (/ num 256))
 182         (lo (% num 256)))
 183     (+ (* 157 (- hi #xa1))
 184        (- lo (if (>= lo #xa1) 98 64)))))
 185
 186 (defun flat-code-to-big5 (num)
 187   "Convert NUM from a `flat code' to Big 5 encoding.
 188 This is the inverse function of `big5-to-flat-code'."
 189
 190   (let ((hi (/ num 157))
 191         (lo (% num 157)))
 192     (+ (* 256 (+ hi #xa1))
 193        (+ lo (if (< lo 63) 64 98)))))
 194
 195 (defun euc-to-flat-code (num)
 196   "Convert NUM in EUC encoding (in GL representation) to a `flat code'.
 197 0x2121 will be mapped to position 0, 0x2122 to position 1, etc.
 198 There are no gaps in the flat code."
 199
 200   (let ((hi (/ num 256))
 201         (lo (% num 256)))
 202     (+ (* 94 (- hi #x21))
 203        (- lo #x21))))
 204
 205 (defun flat-code-to-euc (num)
 206   "Convert NUM from a `flat code' to EUC encoding (in GL representation).
 207 The inverse function of `euc-to-flat-code'.  The high and low bytes are
 208 returned in a list."
 209
 210   (let ((hi (/ num 94))
 211         (lo (% num 94)))
 212     (list (+ hi #x21) (+ lo #x21))))
 213
 214 (defun expand-euc-big5-alist (alist)
 215   "Create a translation table and fills it with data given in ALIST.
 216 Elements of ALIST can be either given as
 217
 218   ((euc-charset . startchar) . (big5-range-begin . big5-range-end))
 219
 220 or as
 221
 222   (euc-character . big5-charcode)
 223
 224 The former maps a range of glyphs in an EUC charset (where STARTCHAR
 225 is in GL representation) to a certain range of Big 5 encoded
 226 characters, the latter maps a single glyph.  Glyphs which can't be
 227 mapped will be represented with the byte 0xFF.
 228
 229 The return value is the filled translation table."
 230
 231   (let ((chartable (make-char-table 'translation-table #xFF))
 232         char
 233         big5
 234         i
 235         end
 236         codepoint
 237         charset)
 238     (dolist (elem alist)
 239       (setq char (car elem)
 240             big5 (cdr elem))
 241       (cond ((and (consp char)
 242                   (consp big5))
 243              (setq i (big5-to-flat-code (car big5))
 244                    end (big5-to-flat-code (cdr big5))
 245                    codepoint (euc-to-flat-code (cdr char))
 246                    charset (car char))
 247              (while (>= end i)
 248                (aset chartable
 249                      (decode-big5-char (flat-code-to-big5 i))
 250                      (apply (function make-char)
 251                             charset
 252                             (flat-code-to-euc codepoint)))
 253                (setq i (1+ i)
 254                      codepoint (1+ codepoint))))
 255             ((and (char-valid-p char)
 256                   (numberp big5))
 257              (setq i (decode-big5-char big5))
 258              (aset chartable i char))
 259             (t
 260              (error "Unknown slot type: %S" elem))))
 261     ;; the return value
 262     chartable)))
 263
 264 ;; All non-CNS encodings are commented out.
 265
 266 (define-translation-table 'big5-to-cns
 267   (eval-when-compile
 268   (expand-euc-big5-alist
 269    '(
 270      ;; Symbols
 271      ((chinese-cns11643-1 . #x2121) . (#xA140 . #xA1F5))
 272      (?\e$(G"X\e(B . #xA1F6)
 273      (?\e$(G"W\e(B . #xA1F7)
 274      ((chinese-cns11643-1 . #x2259) . (#xA1F8 . #xA2AE))
 275      ((chinese-cns11643-1 . #x2421) . (#xA2AF . #xA3BF))
 276      ;; Control codes (vendor dependent)
 277      ((chinese-cns11643-1 . #x4221) . (#xA3C0 . #xA3E0))
 278      ;; Level 1 Ideographs
 279      ((chinese-cns11643-1 . #x4421) . (#xA440 . #xACFD))
 280      (?\e$(GWS\e(B . #xACFE)
 281      ((chinese-cns11643-1 . #x5323) . (#xAD40 . #xAFCF))
 282      ((chinese-cns11643-1 . #x5754) . (#xAFD0 . #xBBC7))
 283      ((chinese-cns11643-1 . #x6B51) . (#xBBC8 . #xBE51))
 284      (?\e$(GkP\e(B . #xBE52)
 285      ((chinese-cns11643-1 . #x6F5C) . (#xBE53 . #xC1AA))
 286      ((chinese-cns11643-1 . #x7536) . (#xC1AB . #xC2CA))
 287      (?\e$(Gu5\e(B . #xC2CB)
 288      ((chinese-cns11643-1 . #x7737) . (#xC2CC . #xC360))
 289      ((chinese-cns11643-1 . #x782E) . (#xC361 . #xC3B8))
 290      (?\e$(Gxe\e(B . #xC3B9)
 291      (?\e$(Gxd\e(B . #xC3BA)
 292      ((chinese-cns11643-1 . #x7866) . (#xC3BB . #xC455))
 293      (?\e$(Gx-\e(B . #xC456)
 294      ((chinese-cns11643-1 . #x7962) . (#xC457 . #xC67E))
 295      ;; Symbols
 296      ((chinese-cns11643-1 . #x2621) . (#xC6A1 . #xC6BE))
 297      ;; Radicals
 298      (?\e$(G'#\e(B . #xC6BF)
 299      (?\e$(G'$\e(B . #xC6C0)
 300      (?\e$(G'&\e(B . #xC6C1)
 301      (?\e$(G'(\e(B . #xC6C2)
 302      (?\e$(G'-\e(B . #xC6C3)
 303      (?\e$(G'.\e(B . #xC6C4)
 304      (?\e$(G'/\e(B . #xC6C5)
 305      (?\e$(G'4\e(B . #xC6C6)
 306      (?\e$(G'7\e(B . #xC6C7)
 307      (?\e$(G':\e(B . #xC6C8)
 308      (?\e$(G'<\e(B . #xC6C9)
 309      (?\e$(G'B\e(B . #xC6CA)
 310      (?\e$(G'G\e(B . #xC6CB)
 311      (?\e$(G'N\e(B . #xC6CC)
 312      (?\e$(G'S\e(B . #xC6CD)
 313      (?\e$(G'T\e(B . #xC6CE)
 314      (?\e$(G'U\e(B . #xC6CF)
 315      (?\e$(G'Y\e(B . #xC6D0)
 316      (?\e$(G'Z\e(B . #xC6D1)
 317      (?\e$(G'a\e(B . #xC6D2)
 318      (?\e$(G'f\e(B . #xC6D3)
 319      (?\e$(G()\e(B . #xC6D4)
 320      (?\e$(G(*\e(B . #xC6D5)
 321      (?\e$(G(c\e(B . #xC6D6)
 322      (?\e$(G(l\e(B . #xC6D7)
 323      ;; Diacritical Marks
 324      ; ((japanese-jisx0208 . #x212F) . (#xC6D8 . #xC6D9))
 325      ;; Japanese Kana Supplement
 326      ; ((japanese-jisx0208 . #x2133) . (#xC6DA . #xC6E3))
 327      ;; Japanese Hiragana
 328      ; ((japanese-jisx0208 . #x2421) . (#xC6E7 . #xC77A))
 329      ;; Japanese Katakana
 330      ; ((japanese-jisx0208 . #x2521) . (#xC77B . #xC7F2))
 331      ;; Cyrillic Characters
 332      ; ((japanese-jisx0208 . #x2721) . (#xC7F3 . #xC854))
 333      ; ((japanese-jisx0208 . #x2751) . (#xC855 . #xC875))
 334      ;; Special Chinese Characters
 335      (?\e$(J!#\e(B . #xC879)
 336      (?\e$(J!$\e(B . #xC87B)
 337      (?\e$(J!*\e(B . #xC87D)
 338      (?\e$(J!R\e(B . #xC8A2)
 339
 340      ;; JIS X 0208 NOT SIGN (cf. U+00AC)
 341      ; (?\e$B"L\e(B . #xC8CD)
 342      ;; JIS X 0212 BROKEN BAR (cf. U+00A6)
 343      ; (?\e$(D"C\e(B . #xC8CE)
 344
 345      ;; GB 2312 characters
 346      ; (?\e$A!d\e(B . #xC8CF)
 347      ; (?\e$A!e\e(B . #xC8D0)
 348         ;;;;; C8D1 - Japanese `(\e$B3t\e(B)'
 349      ; (?\e$A!m\e(B . #xC8D2)
 350         ;;;;; C8D2 - Tel.
 351
 352      ;; Level 2 Ideographs
 353      ((chinese-cns11643-2 . #x2121) . (#xC940 . #xC949))
 354      (?\e$(GDB\e(B . #xC94A);; a duplicate of #xA461
 355      ((chinese-cns11643-2 . #x212B) . (#xC94B . #xC96B))
 356      ((chinese-cns11643-2 . #x214D) . (#xC96C . #xC9BD))
 357      (?\e$(H!L\e(B . #xC9BE)
 358      ((chinese-cns11643-2 . #x217D) . (#xC9BF . #xC9EC))
 359      ((chinese-cns11643-2 . #x224E) . (#xC9ED . #xCAF6))
 360      (?\e$(H"M\e(B . #xCAF7)
 361      ((chinese-cns11643-2 . #x2439) . (#xCAF8 . #xD6CB))
 362      (?\e$(H>c\e(B . #xD6CC)
 363      ((chinese-cns11643-2 . #x3770) . (#xD6CD . #xD779))
 364      (?\e$(H?j\e(B . #xD77A)
 365      ((chinese-cns11643-2 . #x387E) . (#xD77B . #xDADE))
 366      (?\e$(H7o\e(B . #xDADF)
 367      ((chinese-cns11643-2 . #x3E64) . (#xDAE0 . #xDBA6))
 368      ((chinese-cns11643-2 . #x3F6B) . (#xDBA7 . #xDDFB))
 369      (?\e$(HAv\e(B . #xDDFC);; a duplicate of #xDCD1
 370      ((chinese-cns11643-2 . #x4424) . (#xDDFD . #xE8A2))
 371      ((chinese-cns11643-2 . #x554C) . (#xE8A3 . #xE975))
 372      ((chinese-cns11643-2 . #x5723) . (#xE976 . #xEB5A))
 373      ((chinese-cns11643-2 . #x5A29) . (#xEB5B . #xEBF0))
 374      (?\e$(HUK\e(B . #xEBF1)
 375      ((chinese-cns11643-2 . #x5B3F) . (#xEBF2 . #xECDD))
 376      (?\e$(HW"\e(B . #xECDE)
 377      ((chinese-cns11643-2 . #x5C6A) . (#xECDF . #xEDA9))
 378      ((chinese-cns11643-2 . #x5D75) . (#xEDAA . #xEEEA))
 379      (?\e$(Hd/\e(B . #xEEEB)
 380      ((chinese-cns11643-2 . #x6039) . (#xEEEC . #xF055))
 381      (?\e$(H]t\e(B . #xF056)
 382      ((chinese-cns11643-2 . #x6243) . (#xF057 . #xF0CA))
 383      (?\e$(HZ(\e(B . #xF0CB)
 384      ((chinese-cns11643-2 . #x6337) . (#xF0CC . #xF162))
 385      ((chinese-cns11643-2 . #x6430) . (#xF163 . #xF16A))
 386      (?\e$(Hga\e(B . #xF16B)
 387      ((chinese-cns11643-2 . #x6438) . (#xF16C . #xF267))
 388      (?\e$(Hi4\e(B . #xF268)
 389      ((chinese-cns11643-2 . #x6573) . (#xF269 . #xF2C2))
 390      ((chinese-cns11643-2 . #x664E) . (#xF2C3 . #xF374))
 391      ((chinese-cns11643-2 . #x6762) . (#xF375 . #xF465))
 392      ((chinese-cns11643-2 . #x6935) . (#xF466 . #xF4B4))
 393      (?\e$(HfM\e(B . #xF4B5)
 394      ((chinese-cns11643-2 . #x6962) . (#xF4B6 . #xF4FC))
 395      ((chinese-cns11643-2 . #x6A4C) . (#xF4FD . #xF662))
 396      (?\e$(HjK\e(B . #xF663)
 397      ((chinese-cns11643-2 . #x6C52) . (#xF664 . #xF976))
 398      ((chinese-cns11643-2 . #x7167) . (#xF977 . #xF9C3))
 399      (?\e$(Hqf\e(B . #xF9C4)
 400      (?\e$(Hr4\e(B . #xF9C5)
 401      (?\e$(Hr@\e(B . #xF9C6)
 402      ((chinese-cns11643-2 . #x7235) . (#xF9C7 . #xF9D1))
 403      ((chinese-cns11643-2 . #x7241) . (#xF9D2 . #xF9D5))
 404
 405      ;; Additional Ideographs
 406      (?\e$(IC7\e(B . #xF9D6)
 407      (?\e$(IOP\e(B . #xF9D7)
 408      (?\e$(IDN\e(B . #xF9D8)
 409      (?\e$(IPJ\e(B . #xF9D9)
 410      (?\e$(I,]\e(B . #xF9DA)
 411      (?\e$(I=~\e(B . #xF9DB)
 412      (?\e$(IK\\e(B . #xF9DC)
 413     )
 414   ))
 415 )
 416
 417 ;;
 418 (provide 'china-util)
 419
 420 ;;; china-util.el ends here