Implementing euc-tw encoding.

2 files changed, 293 insertions, 2 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index b63d39b5c5a..4a490c35642 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,27 @@
+2001-12-18  Werner Lemberg  <wl@gnu.org>
+
+        * language/chinese.el, language/cyrillic.el,
+        language/czech.el, language/european.el, language/greek.el,
+        language/hebrew.el, language/indian.el, language/japanese.el,
+        language/korean.el, language/lao.el, language/slovak.el,
+        language/thai.el, language/tibetan.el, language/vietnamese.el:
+        Improve documentation strings of coding systems and language infos.
+
+2001-12-18  Werner LEMBERG  <wl@gnu.org>
+
+        Add support for EUC-TW decoding/encoding.
+
+        * language/china-util.el (big5-to-flat-code, flat-code-to-big5,
+        euc-to-flat-code, flat-code-to-euc, expand-euc-big5-alist):
+        New auxiliary functions to build `big5-to-cns'.
+        (big5-to-cns): New translation alist.
+
+        * language/chinese.el: Added new coding system `euc-tw' and its
+        alias `euc-taiwan'.
+        Updated language `Chinese-CNS' to include euc-tw encoding also.
+        (ccl-decode-euc-tw, ccl-encode-euc-tw): New functions for handling
+        euc-tw.
+
 2001-12-18  Dave Love  <fx@gnu.org>
 
         * loadup.el: Add language/utf-8-lang, language/georgian.
diff --git a/lisp/language/china-util.el b/lisp/language/china-util.el
index 8a0a83d834a..2be6ebcdff4 100644
--- a/lisp/language/china-util.el
+++ b/lisp/language/china-util.el
@@ -1,7 +1,8 @@
-;;; china-util.el --- utilities for Chinese
+;;; china-util.el --- utilities for Chinese  -*- coding: iso-2022-7bit -*-
 
 ;; Copyright (C) 1995 Electrotechnical Laboratory, JAPAN.
 ;; Licensed to the Free Software Foundation.
+;; Copyright (C) 1995, 2001 Free Software Foundation, Inc.
 
 ;; Keywords: mule, multilingual, Chinese
 
@@ -26,7 +27,7 @@
 
 ;;; Code:
 
-;; Hz/ZW encoding stuffs
+;; Hz/ZW/EUC-TW encoding stuff
 
 ;; HZ is an encoding method for Chinese character set GB2312 used
 ;; widely in Internet.  It is very similar to 7-bit environment of
@@ -38,6 +39,13 @@
 ;; encodes Chinese characters line by line by starting each line with
 ;; the sequence "zW".  It also uses only 7-bit as HZ.
 
+;; EUC-TW is similar to EUC-KS or EUC-JP.  Its main character set is
+;; plane 1 of CNS 11643; characters of planes 2 to 7 are accessed with
+;; a single shift escape followed by three bytes: the first gives the
+;; plane, the second and third the character code.  Note that characters
+;; of plane 1 are (redundantly) accessible with a single shift escape
+;; also.
+
 ;; ISO-2022 escape sequence to designate GB2312.
 (defvar iso2022-gb-designation "\e$A")
 ;; HZ escape sequence to designate GB2312.
@@ -156,6 +164,265 @@ Return the length of resulting text."
   (interactive)
   (encode-hz-region (point-min) (point-max)))
 
+;; The following sets up a translation table (big5-to-cns) from Big 5
+;; to CNS encoding, using some auxiliary functions to make the code
+;; more readable.
+
+;; Many kudos to Himi!  The used code has been adapted from his
+;; mule-ucs package.
+
+(defun big5-to-flat-code (num)
+  "Convert NUM in Big 5 encoding to a `flat code'.
+0xA140 will be mapped to position 0, 0xA141 to position 1, etc.
+There are no gaps in the flat code."
+
+  (let ((hi (/ num 256))
+        (lo (% num 256)))
+    (+ (* 157 (- hi #xa1))
+       (- lo (if (>= lo #xa1) 98 64)))))
+
+(defun flat-code-to-big5 (num)
+  "Convert NUM from a `flat code' to Big 5 encoding.
+This is the inverse function of `big5-to-flat-code'."
+
+  (let ((hi (/ num 157))
+        (lo (% num 157)))
+    (+ (* 256 (+ hi #xa1))
+       (+ lo (if (< lo 63) 64 98)))))
+
+(defun euc-to-flat-code (num)
+  "Convert NUM in EUC encoding (in GL representation) to a `flat code'.
+0x2121 will be mapped to position 0, 0x2122 to position 1, etc.
+There are no gaps in the flat code."
+
+  (let ((hi (/ num 256))
+        (lo (% num 256)))
+    (+ (* 94 (- hi #x21))
+       (- lo #x21))))
+
+(defun flat-code-to-euc (num)
+  "Convert NUM from a `flat code' to EUC encoding (in GL representation).
+The inverse function of `euc-to-flat-code'.  The high and low bytes are
+returned in a list."
+
+  (let ((hi (/ num 94))
+        (lo (% num 94)))
+    (list (+ hi #x21) (+ lo #x21))))
+
+(defun expand-euc-big5-alist (alist)
+  "Create a translation table and fills it with data given in ALIST.
+Elements of ALIST can be either given as
+
+  ((euc-charset . startchar) . (big5-range-begin . big5-range-end))
+
+or as
+
+  (euc-character . big5-charcode)
+
+The former maps a range of glyphs in an EUC charset (where STARTCHAR
+is in GL representation) to a certain range of Big 5 encoded
+characters, the latter maps a single glyph.  Glyphs which can't be
+mapped will be represented with the byte 0xFF.
+
+The return value is the filled translation table."
+
+  (let (chartable
+        elem
+        result
+        char
+        big5
+        i
+        end
+        codepoint
+        charset)
+    (setq chartable (make-char-table 'translation-table #xFF))
+    (while alist
+      (setq elem (car alist)
+            char (car elem)
+            big5 (cdr elem)
+            alist (cdr alist))
+      (cond ((and (consp char)
+                  (consp big5))
+               (setq i (big5-to-flat-code (car big5))
+                     end (big5-to-flat-code (cdr big5))
+                     codepoint (euc-to-flat-code (cdr char))
+                     charset (car char))
+               (while (>= end i)
+                 (aset chartable
+                       (decode-big5-char (flat-code-to-big5 i))
+                       (apply (function make-char)
+                              charset
+                              (flat-code-to-euc codepoint)))
+                 (setq i (1+ i)
+                       codepoint (1+ codepoint)))
+            )
+            ((and (char-valid-p char)
+                  (numberp big5))
+               (setq i (decode-big5-char big5))
+               (aset chartable i char)
+            )
+            (t
+             (error "Unknown slot type: %S" elem)
+            )
+      )
+    )
+    ;; the return value
+    chartable
+  )
+)
+
+;; All non-CNS encodings are commented out.
+
+(define-translation-table 'big5-to-cns
+  (expand-euc-big5-alist
+   '(
+     ;; Symbols
+     ((chinese-cns11643-1 . #x2121) . (#xA140 . #xA1F5))
+     (?$(G"X(B . #xA1F6)
+     (?$(G"W(B . #xA1F7)
+     ((chinese-cns11643-1 . #x2259) . (#xA1F8 . #xA2AE))
+     ((chinese-cns11643-1 . #x2421) . (#xA2AF . #xA3BF))
+     ;; Control codes (vendor dependent)
+     ((chinese-cns11643-1 . #x4221) . (#xA3C0 . #xA3E0))
+     ;; Level 1 Ideographs
+     ((chinese-cns11643-1 . #x4421) . (#xA440 . #xACFD))
+     (?$(GWS(B . #xACFE)
+     ((chinese-cns11643-1 . #x5323) . (#xAD40 . #xAFCF))
+     ((chinese-cns11643-1 . #x5754) . (#xAFD0 . #xBBC7))
+     ((chinese-cns11643-1 . #x6B51) . (#xBBC8 . #xBE51))
+     (?$(GkP(B . #xBE52)
+     ((chinese-cns11643-1 . #x6F5C) . (#xBE53 . #xC1AA))
+     ((chinese-cns11643-1 . #x7536) . (#xC1AB . #xC2CA))
+     (?$(Gu5(B . #xC2CB)
+     ((chinese-cns11643-1 . #x7737) . (#xC2CC . #xC360))
+     ((chinese-cns11643-1 . #x782E) . (#xC361 . #xC3B8))
+     (?$(Gxe(B . #xC3B9)
+     (?$(Gxd(B . #xC3BA)
+     ((chinese-cns11643-1 . #x7866) . (#xC3BB . #xC455))
+     (?$(Gx-(B . #xC456)
+     ((chinese-cns11643-1 . #x7962) . (#xC457 . #xC67E))
+     ;; Symbols
+     ((chinese-cns11643-1 . #x2621) . (#xC6A1 . #xC6BE))
+     ;; Radicals
+     (?$(G'#(B . #xC6BF)
+     (?$(G'$(B . #xC6C0)
+     (?$(G'&(B . #xC6C1)
+     (?$(G'((B . #xC6C2)
+     (?$(G'-(B . #xC6C3)
+     (?$(G'.(B . #xC6C4)
+     (?$(G'/(B . #xC6C5)
+     (?$(G'4(B . #xC6C6)
+     (?$(G'7(B . #xC6C7)
+     (?$(G':(B . #xC6C8)
+     (?$(G'<(B . #xC6C9)
+     (?$(G'B(B . #xC6CA)
+     (?$(G'G(B . #xC6CB)
+     (?$(G'N(B . #xC6CC)
+     (?$(G'S(B . #xC6CD)
+     (?$(G'T(B . #xC6CE)
+     (?$(G'U(B . #xC6CF)
+     (?$(G'Y(B . #xC6D0)
+     (?$(G'Z(B . #xC6D1)
+     (?$(G'a(B . #xC6D2)
+     (?$(G'f(B . #xC6D3)
+     (?$(G()(B . #xC6D4)
+     (?$(G(*(B . #xC6D5)
+     (?$(G(c(B . #xC6D6)
+     (?$(G(l(B . #xC6D7)
+     ;; Diacritical Marks
+     ; ((japanese-jisx0208 . #x212F) . (#xC6D8 . #xC6D9))
+     ;; Japanese Kana Supplement
+     ; ((japanese-jisx0208 . #x2133) . (#xC6DA . #xC6E3))
+     ;; Japanese Hiragana
+     ; ((japanese-jisx0208 . #x2421) . (#xC6E7 . #xC77A))
+     ;; Japanese Katakana
+     ; ((japanese-jisx0208 . #x2521) . (#xC77B . #xC7F2))
+     ;; Cyrillic Characters
+     ; ((japanese-jisx0208 . #x2721) . (#xC7F3 . #xC854))
+     ; ((japanese-jisx0208 . #x2751) . (#xC855 . #xC875))
+     ;; Special Chinese Characters
+     (?$(J!#(B . #xC879)
+     (?$(J!$(B . #xC87B)
+     (?$(J!*(B . #xC87D)
+     (?$(J!R(B . #xC8A2)
+
+     ;; JIS X 0208 NOT SIGN (cf. U+00AC)
+     ; (?$B"L(B . #xC8CD)
+     ;; JIS X 0212 BROKEN BAR (cf. U+00A6)
+     ; (?$(D"C(B . #xC8CE)
+
+     ;; GB 2312 characters
+     ; (?$A!d(B . #xC8CF)
+     ; (?$A!e(B . #xC8D0)
+        ;;;;; C8D1 - Japanese `($B3t(B)'
+     ; (?$A!m(B . #xC8D2)
+        ;;;;; C8D2 - Tel.
+
+     ;; Level 2 Ideographs
+     ((chinese-cns11643-2 . #x2121) . (#xC940 . #xC949))
+     (?$(GDB(B . #xC94A);; a duplicate of #xA461
+     ((chinese-cns11643-2 . #x212B) . (#xC94B . #xC96B))
+     ((chinese-cns11643-2 . #x214D) . (#xC96C . #xC9BD))
+     (?$(H!L(B . #xC9BE)
+     ((chinese-cns11643-2 . #x217D) . (#xC9BF . #xC9EC))
+     ((chinese-cns11643-2 . #x224E) . (#xC9ED . #xCAF6))
+     (?$(H"M(B . #xCAF7)
+     ((chinese-cns11643-2 . #x2439) . (#xCAF8 . #xD6CB))
+     (?$(H>c(B . #xD6CC)
+     ((chinese-cns11643-2 . #x3770) . (#xD6CD . #xD779))
+     (?$(H?j(B . #xD77A)
+     ((chinese-cns11643-2 . #x387E) . (#xD77B . #xDADE))
+     (?$(H7o(B . #xDADF)
+     ((chinese-cns11643-2 . #x3E64) . (#xDAE0 . #xDBA6))
+     ((chinese-cns11643-2 . #x3F6B) . (#xDBA7 . #xDDFB))
+     (?$(HAv(B . #xDDFC);; a duplicate of #xDCD1
+     ((chinese-cns11643-2 . #x4424) . (#xDDFD . #xE8A2))
+     ((chinese-cns11643-2 . #x554C) . (#xE8A3 . #xE975))
+     ((chinese-cns11643-2 . #x5723) . (#xE976 . #xEB5A))
+     ((chinese-cns11643-2 . #x5A29) . (#xEB5B . #xEBF0))
+     (?$(HUK(B . #xEBF1)
+     ((chinese-cns11643-2 . #x5B3F) . (#xEBF2 . #xECDD))
+     (?$(HW"(B . #xECDE)
+     ((chinese-cns11643-2 . #x5C6A) . (#xECDF . #xEDA9))
+     ((chinese-cns11643-2 . #x5D75) . (#xEDAA . #xEEEA))
+     (?$(Hd/(B . #xEEEB)
+     ((chinese-cns11643-2 . #x6039) . (#xEEEC . #xF055))
+     (?$(H]t(B . #xF056)
+     ((chinese-cns11643-2 . #x6243) . (#xF057 . #xF0CA))
+     (?$(HZ((B . #xF0CB)
+     ((chinese-cns11643-2 . #x6337) . (#xF0CC . #xF162))
+     ((chinese-cns11643-2 . #x6430) . (#xF163 . #xF16A))
+     (?$(Hga(B . #xF16B)
+     ((chinese-cns11643-2 . #x6438) . (#xF16C . #xF267))
+     (?$(Hi4(B . #xF268)
+     ((chinese-cns11643-2 . #x6573) . (#xF269 . #xF2C2))
+     ((chinese-cns11643-2 . #x664E) . (#xF2C3 . #xF374))
+     ((chinese-cns11643-2 . #x6762) . (#xF375 . #xF465))
+     ((chinese-cns11643-2 . #x6935) . (#xF466 . #xF4B4))
+     (?$(HfM(B . #xF4B5)
+     ((chinese-cns11643-2 . #x6962) . (#xF4B6 . #xF4FC))
+     ((chinese-cns11643-2 . #x6A4C) . (#xF4FD . #xF662))
+     (?$(HjK(B . #xF663)
+     ((chinese-cns11643-2 . #x6C52) . (#xF664 . #xF976))
+     ((chinese-cns11643-2 . #x7167) . (#xF977 . #xF9C3))
+     (?$(Hqf(B . #xF9C4)
+     (?$(Hr4(B . #xF9C5)
+     (?$(Hr@(B . #xF9C6)
+     ((chinese-cns11643-2 . #x7235) . (#xF9C7 . #xF9D1))
+     ((chinese-cns11643-2 . #x7241) . (#xF9D2 . #xF9D5))
+
+     ;; Additional Ideographs
+     (?$(IC7(B . #xF9D6)
+     (?$(IOP(B . #xF9D7)
+     (?$(IDN(B . #xF9D8)
+     (?$(IPJ(B . #xF9D9)
+     (?$(I,](B . #xF9DA)
+     (?$(I=~(B . #xF9DB)
+     (?$(IK\(B . #xF9DC)
+    )
+  )
+)
+
 ;;
 (provide 'china-util)