+++ /dev/null
-;;; utf-8.el --- Limited UTF-8 decoding/encoding support -*- coding: iso-2022-7bit -*-
-
-;; Copyright (C) 2001 Electrotechnical Laboratory, JAPAN.
-;; Licensed to the Free Software Foundation.
-;; Copyright (C) 2001 Free Software Foundation, Inc.
-
-;; Author: TAKAHASHI Naoto <ntakahas@m17n.org>
-;; Keywords: multilingual, Unicode, UTF-8, i18n
-
-;; This file is part of GNU Emacs.
-
-;; GNU Emacs is free software; you can redistribute it and/or modify
-;; it under the terms of the GNU General Public License as published by
-;; the Free Software Foundation; either version 2, or (at your option)
-;; any later version.
-
-;; GNU Emacs is distributed in the hope that it will be useful,
-;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-;; GNU General Public License for more details.
-
-;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
-
-;;; Commentary:
-
-;; The coding-system `mule-utf-8' basically supports encoding/decoding
-;; of the following character sets to and from UTF-8:
-;;
-;; ascii
-;; eight-bit-control
-;; latin-iso8859-1
-;; mule-unicode-0100-24ff
-;; mule-unicode-2500-33ff
-;; mule-unicode-e000-ffff
-;;
-;; On decoding, Unicode characters that do not fit into the above
-;; character sets are handled as `eight-bit-control' or
-;; `eight-bit-graphic' characters to retain the information about the
-;; original byte sequence.
-;;
-;; Characters from other character sets can be encoded with
-;; mule-utf-8 by populating the table `ucs-mule-to-mule-unicode' and
-;; registering the translation with `register-char-codings'.
-
-;; UTF-8 is defined in RFC 2279. A sketch of the encoding is:
-
-;; scalar | utf-8
-;; value | 1st byte | 2nd byte | 3rd byte
-;; --------------------+-----------+-----------+----------
-;; 0000 0000 0xxx xxxx | 0xxx xxxx | |
-;; 0000 0yyy yyxx xxxx | 110y yyyy | 10xx xxxx |
-;; zzzz yyyy yyxx xxxx | 1110 zzzz | 10yy yyyy | 10xx xxxx
-
-;;; Code:
-
-(defvar ucs-mule-to-mule-unicode (make-translation-table)
- "Translation table for encoding to `mule-utf-8'.")
-;; Could have been done by ucs-tables loaded before.
-(unless (get 'ucs-mule-to-mule-unicode 'translation-table)
- (define-translation-table 'ucs-mule-to-mule-unicode ucs-mule-to-mule-unicode))
-(define-ccl-program ccl-decode-mule-utf-8
- ;;
- ;; charset | bytes in utf-8 | bytes in emacs
- ;; -----------------------+----------------+---------------
- ;; ascii | 1 | 1
- ;; -----------------------+----------------+---------------
- ;; eight-bit-control | 2 | 2
- ;; eight-bit-graphic | 2 | 1
- ;; latin-iso8859-1 | 2 | 2
- ;; -----------------------+----------------+---------------
- ;; mule-unicode-0100-24ff | 2 | 4
- ;; (< 0800) | |
- ;; -----------------------+----------------+---------------
- ;; mule-unicode-0100-24ff | 3 | 4
- ;; (>= 8000) | |
- ;; mule-unicode-2500-33ff | 3 | 4
- ;; mule-unicode-e000-ffff | 3 | 4
- ;;
- ;; Thus magnification factor is two.
- ;;
- `(2
- ((r5 = ,(charset-id 'eight-bit-control))
- (r6 = ,(charset-id 'eight-bit-graphic))
- (loop
- (read r0)
-
- ;; 1byte encoding, i.e., ascii
- (if (r0 < #x80)
- (write r0)
-
- ;; 2 byte encoding 00000yyyyyxxxxxx = 110yyyyy 10xxxxxx
- (if (r0 < #xe0)
- ((read r1)
-
- (if ((r1 & #b11000000) != #b10000000)
- ;; Invalid 2-byte sequence
- ((if (r0 < #xa0)
- (write-multibyte-character r5 r0)
- (write-multibyte-character r6 r0))
- (if (r1 < #x80)
- (write r1)
- (if (r1 < #xa0)
- (write-multibyte-character r5 r1)
- (write-multibyte-character r6 r1))))
-
- ((r0 &= #x1f)
- (r0 <<= 6)
- (r1 &= #x3f)
- (r1 += r0)
- ;; Now r1 holds scalar value
-
- ;; eight-bit-control
- (if (r1 < 160)
- ((write-multibyte-character r5 r1))
-
- ;; latin-iso8859-1
- (if (r1 < 256)
- ((r0 = ,(charset-id 'latin-iso8859-1))
- (r1 -= 128)
- (write-multibyte-character r0 r1))
-
- ;; mule-unicode-0100-24ff (< 0800)
- ((r0 = ,(charset-id 'mule-unicode-0100-24ff))
- (r1 -= #x0100)
- (r2 = (((r1 / 96) + 32) << 7))
- (r1 %= 96)
- (r1 += (r2 + 32))
- (write-multibyte-character r0 r1)))))))
-
- ;; 3byte encoding
- ;; zzzzyyyyyyxxxxxx = 1110zzzz 10yyyyyy 10xxxxxx
- (if (r0 < #xf0)
- ((read r1 r2)
-
- ;; This is set to 1 if the encoding is invalid.
- (r4 = 0)
-
- (r3 = (r1 & #b11000000))
- (r3 |= ((r2 >> 2) & #b00110000))
- (if (r3 != #b10100000)
- (r4 = 1)
- ((r3 = ((r0 & #x0f) << 12))
- (r3 += ((r1 & #x3f) << 6))
- (r3 += (r2 & #x3f))
- (if (r3 < #x0800)
- (r4 = 1))))
-
- (if (r4 != 0)
- ;; Invalid 3-byte sequence
- ((if (r0 < #xa0)
- (write-multibyte-character r5 r0)
- (write-multibyte-character r6 r0))
- (if (r1 < #x80)
- (write r1)
- (if (r1 < #xa0)
- (write-multibyte-character r5 r1)
- (write-multibyte-character r6 r1)))
- (if (r2 < #x80)
- (write r2)
- (if (r2 < #xa0)
- (write-multibyte-character r5 r2)
- (write-multibyte-character r6 r2))))
-
- ;; mule-unicode-0100-24ff (>= 0800)
- ((if (r3 < #x2500)
- ((r0 = ,(charset-id 'mule-unicode-0100-24ff))
- (r3 -= #x0100)
- (r3 //= 96)
- (r1 = (r7 + 32))
- (r1 += ((r3 + 32) << 7))
- (write-multibyte-character r0 r1))
-
- ;; mule-unicode-2500-33ff
- (if (r3 < #x3400)
- ((r0 = ,(charset-id 'mule-unicode-2500-33ff))
- (r3 -= #x2500)
- (r3 //= 96)
- (r1 = (r7 + 32))
- (r1 += ((r3 + 32) << 7))
- (write-multibyte-character r0 r1))
-
- ;; U+3400 .. U+DFFF
- ;; keep those bytes as eight-bit-{control|graphic}
- (if (r3 < #xe000)
- ( ;; #xe0 <= r0 < #xf0, so r0 is eight-bit-graphic
- (r3 = r6)
- (write-multibyte-character r3 r0)
- (if (r1 < #xa0)
- (r3 = r5))
- (write-multibyte-character r3 r1)
- (if (r2 < #xa0)
- (r3 = r5)
- (r3 = r6))
- (write-multibyte-character r3 r2))
-
- ;; mule-unicode-e000-ffff
- ((r0 = ,(charset-id 'mule-unicode-e000-ffff))
- (r3 -= #xe000)
- (r3 //= 96)
- (r1 = (r7 + 32))
- (r1 += ((r3 + 32) << 7))
- (write-multibyte-character r0 r1))))))))
-
- ;; 4byte encoding
- ;; keep those bytes as eight-bit-{control|graphic}
- ((read r1 r2 r3)
- ;; r0 > #xf0, thus eight-bit-graphic
- (write-multibyte-character r6 r0)
- (if (r1 < #xa0)
- (write-multibyte-character r5 r1)
- (write-multibyte-character r6 r1))
- (if (r2 < #xa0)
- (write-multibyte-character r5 r2)
- (write-multibyte-character r6 r2))
- (if (r3 < #xa0)
- (write-multibyte-character r5 r3)
- (write-multibyte-character r6 r3))))))
-
- (repeat))))
-
- "CCL program to decode UTF-8.
-Basic decoding is done into the charsets ascii, latin-iso8859-1 and
-mule-unicode-*. Encodings of un-representable Unicode characters are
-decoded asis into eight-bit-control and eight-bit-graphic
-characters.")
-
-(define-ccl-program ccl-encode-mule-utf-8
- `(1
- ((r5 = -1)
- (loop
- (if (r5 < 0)
- ((r1 = -1)
- (read-multibyte-character r0 r1)
- (translate-character ucs-mule-to-mule-unicode r0 r1))
- (;; We have already done read-multibyte-character.
- (r0 = r5)
- (r1 = r6)
- (r5 = -1)))
-
- (if (r0 == ,(charset-id 'ascii))
- (write r1)
-
- (if (r0 == ,(charset-id 'latin-iso8859-1))
- ;; r1 scalar utf-8
- ;; 0000 0yyy yyxx xxxx 110y yyyy 10xx xxxx
- ;; 20 0000 0000 1010 0000 1100 0010 1010 0000
- ;; 7f 0000 0000 1111 1111 1100 0011 1011 1111
- ((r0 = (((r1 & #x40) >> 6) | #xc2))
- (r1 &= #x3f)
- (r1 |= #x80)
- (write r0 r1))
-
- (if (r0 == ,(charset-id 'mule-unicode-0100-24ff))
- ((r0 = ((((r1 & #x3f80) >> 7) - 32) * 96))
- ;; #x3f80 == (0011 1111 1000 0000)b
- (r1 &= #x7f)
- (r1 += (r0 + 224)) ; 240 == -32 + #x0100
- ;; now r1 holds scalar value
- (if (r1 < #x0800)
- ;; 2byte encoding
- ((r0 = (((r1 & #x07c0) >> 6) | #xc0))
- ;; #x07c0 == (0000 0111 1100 0000)b
- (r1 &= #x3f)
- (r1 |= #x80)
- (write r0 r1))
- ;; 3byte encoding
- ((r0 = (((r1 & #xf000) >> 12) | #xe0))
- (r2 = ((r1 & #x3f) | #x80))
- (r1 &= #x0fc0)
- (r1 >>= 6)
- (r1 |= #x80)
- (write r0 r1 r2))))
-
- (if (r0 == ,(charset-id 'mule-unicode-2500-33ff))
- ((r0 = ((((r1 & #x3f80) >> 7) - 32) * 96))
- (r1 &= #x7f)
- (r1 += (r0 + 9440)) ; 9440 == -32 + #x2500
- (r0 = (((r1 & #xf000) >> 12) | #xe0))
- (r2 = ((r1 & #x3f) | #x80))
- (r1 &= #x0fc0)
- (r1 >>= 6)
- (r1 |= #x80)
- (write r0 r1 r2))
-
- (if (r0 == ,(charset-id 'mule-unicode-e000-ffff))
- ((r0 = ((((r1 & #x3f80) >> 7) - 32) * 96))
- (r1 &= #x7f)
- (r1 += (r0 + 57312)) ; 57312 == -160 + #xe000
- (r0 = (((r1 & #xf000) >> 12) | #xe0))
- (r2 = ((r1 & #x3f) | #x80))
- (r1 &= #x0fc0)
- (r1 >>= 6)
- (r1 |= #x80)
- (write r0 r1 r2))
-
- (if (r0 == ,(charset-id 'eight-bit-control))
- ;; r1 scalar utf-8
- ;; 0000 0yyy yyxx xxxx 110y yyyy 10xx xxxx
- ;; 80 0000 0000 1000 0000 1100 0010 1000 0000
- ;; 9f 0000 0000 1001 1111 1100 0010 1001 1111
- ((write #xc2)
- (write r1))
-
- (if (r0 == ,(charset-id 'eight-bit-graphic))
- ;; r1 scalar utf-8
- ;; 0000 0yyy yyxx xxxx 110y yyyy 10xx xxxx
- ;; a0 0000 0000 1010 0000 1100 0010 1010 0000
- ;; ff 0000 0000 1111 1111 1101 1111 1011 1111
- ((write r1)
- (r1 = -1)
- (read-multibyte-character r0 r1)
- (if (r0 != ,(charset-id 'eight-bit-graphic))
- (if (r0 != ,(charset-id 'eight-bit-control))
- ((r5 = r0)
- (r6 = r1))))
- (if (r5 < 0)
- ((read-multibyte-character r0 r2)
- (if (r0 != ,(charset-id 'eight-bit-graphic))
- (if (r0 != ,(charset-id 'eight-bit-control))
- ((r5 = r0)
- (r6 = r2))))
- (if (r5 < 0)
- (write r1 r2)
- (if (r1 < #xa0)
- (write r1)
- ((write #xc2)
- (write r1)))))))
-
- ;; Unsupported character.
- ;; Output U+FFFD, which is `ef bf bd' in UTF-8.
- ((write #xef)
- (write #xbf)
- (write #xbd)))))))))
- (repeat)))
- (if (r1 >= #xa0)
- (write r1)
- (if (r1 >= #x80)
- ((write #xc2)
- (write r1)))))
-
- "CCL program to encode into UTF-8.
-Only characters from the charsets ascii, eight-bit-control,
-eight-bit-graphic, latin-iso8859-1 and mule-unicode-* are recognized.
-Others are encoded as U+FFFD.")
-
-;; Dummy definition so that the CCL can be checked correctly; the
-;; actual data are loaded on demand.
-(unless (boundp 'ucs-mule-8859-to-mule-unicode) ; don't zap it
- (define-translation-table 'ucs-mule-8859-to-mule-unicode))
-
-(defsubst utf-8-untranslated-to-ucs ()
- (let ((b1 (char-after))
- (b2 (char-after (1+ (point))))
- (b3 (char-after (+ 2 (point))))
- (b4 (char-after (+ 4 (point)))))
- (if (and b1 b2 b3)
- (cond ((< b1 ?\xf0)
- (setq b2 (lsh (logand b2 ?\x3f) 6))
- (setq b3 (logand b3 ?\x3f))
- (logior b3 (logior b2 (lsh (logand b1 ?\x0f) 12))))
- (b4
- (setq b2 (lsh (logand b2 ?\x3f) 12))
- (setq b3 (lsh (logand b3 ?\x3f) 6))
- (setq b4 (logand b4 ?\x3f))
- (logior b4 (logior b3 (logior b2 (lsh (logand b1 ?\x07)
- 18)))))))))
-
-(defun utf-8-help-echo (window object position)
- (format "Untranslated Unicode U+%04X"
- (get-char-property position 'untranslated-utf-8 object)))
-
-(defvar utf-8-subst-table nil
- "If non-nil, a hash table mapping `untranslatable utf-8' to Emacs characters.")
-
-;; We compose the untranslatable sequences into a single character.
-;; This is infelicitous for editing, because there's currently no
-;; mechanism for treating compositions as atomic, but is OK for
-;; display. We try to compose an appropriate character from a hash
-;; table of CJK characters to display correctly. Otherwise we use
-;; U+FFFD. What we really should have is hash table lookup from CCL
-;; so that we could do this properly. This function GCs too much.
-(defsubst utf-8-compose ()
- "Put a suitable composition on an untranslatable sequence.
-Return the sequence's length."
- (let* ((u (utf-8-untranslated-to-ucs))
- (l (and u (if (>= u ?\x10000)
- 4
- 3)))
- (subst (and utf-8-subst-table (gethash u utf-8-subst-table))))
- (when u
- (put-text-property (point) (min (point-max) (+ l (point)))
- 'untranslated-utf-8 u)
- (unless subst
- (put-text-property (point) (min (point-max) (+ l (point)))
- 'help-echo 'utf-8-help-echo)
- (setq subst ?\e$,3u=\e(B))
- (compose-region (point) (+ l (point)) subst)
- l)))
-
-(defcustom utf-8-compose-scripts nil
- "*Non-nil means compose various scipts on decoding utf-8 text."
- :group 'mule
- :type 'boolean) ; omitted in Emacs 21.1
-
-(defun utf-8-post-read-conversion (length)
- "Compose untranslated utf-8 sequences into single characters.
-Also compose particular scripts if `utf-8-compose-scripts' is non-nil."
- (save-excursion
- ;; Can't do eval-when-compile to insert a multibyte constant
- ;; version of the string in the loop, since it's always loaded as
- ;; unibyte from a byte-compiled file.
- (let ((range (string-as-multibyte "^\341-\377")))
- (while (and (skip-chars-forward
- range)
- (not (eobp)))
- (forward-char (utf-8-compose)))))
- ;; Fixme: Takahashi-san implies it may not work this easily -- needs
- ;; checking with him.
- (when (and utf-8-compose-scripts (> length 1))
- ;; These currently have definitions which cover the relevant
- ;; Unicodes. We could avoid loading thai-util &c by checking
- ;; whether the region contains any characters with the appropriate
- ;; categories. There aren't yet Unicode-based rules for Tibetan.
- (save-excursion (setq length (diacritic-post-read-conversion length)))
- (save-excursion (setq length (thai-post-read-conversion length)))
- (save-excursion (setq length (lao-post-read-conversion length)))
- (save-excursion (setq length (devanagari-post-read-conversion length))))
- length)
-
-(defun utf-8-pre-write-conversion (beg end)
- "Semi-dummy pre-write function effectively to autoload ucs-tables."
- ;; Ensure translation table is loaded.
- (require 'ucs-tables)
- ;; Don't do this again.
- (coding-system-put 'mule-utf-8 'pre-write-conversion nil)
- nil)
-
-(make-coding-system
- 'mule-utf-8 4 ?u
- "UTF-8 encoding for Emacs-supported Unicode characters.
-The supported Emacs character sets are the following, plus others
-which may be included in the translation table
-`ucs-mule-to-mule-unicode':
- ascii
- eight-bit-control
- eight-bit-graphic
- latin-iso8859-1
- latin-iso8859-2
- latin-iso8859-3
- latin-iso8859-4
- cyrillic-iso8859-5
- greek-iso8859-7
- hebrew-iso8859-8
- latin-iso8859-9
- latin-iso8859-14
- latin-iso8859-15
- mule-unicode-0100-24ff
- mule-unicode-2500-33ff
- mule-unicode-e000-ffff
-
-Unicode characters out of the ranges U+0000-U+33FF and U+E200-U+FFFF
-are decoded into sequences of eight-bit-control and eight-bit-graphic
-characters to preserve their byte sequences and composed to display as
-a single character. Emacs characters that can't be encoded to these
-ranges are encoded as U+FFFD."
-
- '(ccl-decode-mule-utf-8 . ccl-encode-mule-utf-8)
- '((safe-charsets
- ascii
- eight-bit-control
- eight-bit-graphic
- latin-iso8859-1
- latin-iso8859-15
- latin-iso8859-14
- latin-iso8859-9
- hebrew-iso8859-8
- greek-iso8859-7
- cyrillic-iso8859-5
- latin-iso8859-4
- latin-iso8859-3
- latin-iso8859-2
- vietnamese-viscii-lower
- vietnamese-viscii-upper
- thai-tis620
- ipa
- ethiopic
- indian-is13194
- katakana-jisx0201
- chinese-sisheng
- lao
- mule-unicode-0100-24ff
- mule-unicode-2500-33ff
- mule-unicode-e000-ffff)
- (mime-charset . utf-8)
- (coding-category . coding-category-utf-8)
- (valid-codes (0 . 255))
- (pre-write-conversion . utf-8-pre-write-conversion)
- (post-read-conversion . utf-8-post-read-conversion)))
-
-(define-coding-system-alias 'utf-8 'mule-utf-8)
-
-;; I think this needs special private charsets defined for the
-;; untranslated sequences, if it's going to work well.
-
-;;; (defun utf-8-compose-function (pos to pattern &optional string)
-;;; (let* ((prop (get-char-property pos 'composition string))
-;;; (l (and prop (- (cadr prop) (car prop)))))
-;;; (cond ((and l (> l (- to pos)))
-;;; (delete-region pos to))
-;;; ((and (> (char-after pos) 224)
-;;; (< (char-after pos) 256)
-;;; (save-restriction
-;;; (narrow-to-region pos to)
-;;; (utf-8-compose)))
-;;; t))))
-
-;;; (dotimes (i 96)
-;;; (aset composition-function-table
-;;; (+ 128 i)
-;;; `((,(string-as-multibyte "[\200-\237\240-\377]")
-;;; . utf-8-compose-function))))
-
-;;; utf-8.el ends here
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