Update FSF's address.

[bpt/emacs.git] / lisp / international / iso-acc.el

;;; iso-acc.el -- minor mode providing electric accent keys

;; Copyright (C) 1993, 1994 Free Software Foundation, Inc.

;; Author: Johan Vromans <jv@mh.nl>
;; Version: 1.7 (modified)
;; Maintainer: FSF
;; Keywords: 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:

;; Function `iso-accents-mode' activates a minor mode in which
;; typewriter "dead keys" are emulated.  The purpose of this emulation
;; is to provide a simple means for inserting accented characters
;; according to the ISO-8859-1 character set.
;;
;; In `iso-accents-mode', pseudo accent characters are used to
;; introduce accented keys.  The pseudo-accent characters are:
;;
;;   '  (minute)    -> grave accent
;;   `  (backtick)  -> acute accent
;;   "  (second)    -> diaeresis
;;   ^  (caret)     -> circumflex
;;   ~  (tilde)     -> tilde over the character
;;   /  (slash)     -> slash through the character.
;;                  Also:  /A is A-with-ring and /E is AE ligature.
;;
;; The action taken depends on the key that follows the pseudo accent.
;; In general: 
;;
;;   pseudo-accent + appropriate letter -> accented letter
;;   pseudo-accent + space -> pseudo-accent
;;   pseudo-accent + pseudo-accent -> accent (if available)
;;   pseudo-accent + other -> pseudo-accent + other
;;
;; If the pseudo-accent is followed by anything else than a 
;; self-insert-command, the dead-key code is terminated, the
;; pseudo-accent inserted 'as is' and the bell is rung to signal this.
;;
;; Function `iso-accents-mode' can be used to enable the iso accents
;; minor mode, or disable it.

;; If you want only some of these characters to serve as accents,
;; add a language to iso-languages which specifies the accent characters
;; that you want, then select the language with iso-accents-customize.
\f
;;; Code:

(provide 'iso-acc)

(defvar iso-languages
  '(("portuguese"
     (?' ?` ?^ ?\" ?~)
     (((?' ?A) ?\301) ((?' ?E) ?\311) ((?' ?I) ?\315) ((?' ?O) ?\323)
      ((?' ?U) ?\332) ((?' ?C) ?\307) ((?' ?a) ?\341) ((?' ?e) ?\351)
      ((?' ?i) ?\355) ((?' ?o) ?\363) ((?' ?u) ?\372) ((?' ?c) ?\347)
      ((?' ? ) ?') ((?` ?A) ?\300) ((?` ?a) ?\340) ((?` ? ) ?`)
      ((?^ ?A) ?\302) ((?^ ?E) ?\312) ((?^ ?O) ?\324) ((?^ ?a) ?\342)
      ((?^ ?e) ?\352) ((?^ ?o) ?\364) ((?^ ? ) ?^) ((?\" ?U) ?\334)
      ((?\" ?u) ?\374) ((?\" ? ) ?\") ((?\~ ?A) ?\303) ((?\~ ?O) ?\325)
      ((?\~ ?a) ?\343) ((?\~ ?o) ?\365) ((?\~ ?\ ) ?\~)))
    ("irish"
     (?')
     (((?' ?A) ?\301) ((?' ?E) ?\311) ((?' ?I) ?\315) ((?' ?O) ?\323)
      ((?' ?U) ?\332) ((?' ?a) ?\341) ((?' ?e) ?\351)
      ((?' ?i) ?\355) ((?' ?o) ?\363) ((?' ?u) ?\372) 
      ((?' ? ) ?') ))  
    ("french"
     (?' ?` ?^ ?\" ?~)
     (((?' ?A) ?\301) ((?' ?E) ?\311) ((?' ?I) ?\315) ((?' ?O) ?\323)
      ((?' ?U) ?\332) ((?' ?C) ?\307) ((?' ?a) ?\341) ((?' ?e) ?\351)
      ((?' ?i) ?\355) ((?' ?o) ?\363) ((?' ?u) ?\372) ((?' ?c) ?\347)
      ((?' ? ) ?') ((?` ?A) ?\300) ((?` ?E) ?\310) ((?` ?a) ?\340)
      ((?` ?e) ?\350) ((?` ? ) ?`) ((?^ ?A) ?\302) ((?^ ?E) ?\312)
      ((?^ ?I) ?\316) ((?^ ?O) ?\324) ((?^ ?U) ?\333) ((?^ ?a) ?\342)
      ((?^ ?e) ?\352) ((?^ ?i) ?\356) ((?^ ?o) ?\364) ((?^ ?u) ?\373)
      ((?^ ? ) ?^) ((?\" ?U) ?\334) ((?\" ?u) ?\374) ((?\" ? ) ?\")
      ((?\~ ?A) ?\303) ((?\~ ?O) ?\325) ((?\~ ?a) ?\343) ((?\~ ?o) ?\365)
      ((?\~ ?\ ) ?\~)))
    ("default"
     (?' ?` ?^ ?\" ?~ ?/)
     (((?' ?A) ?\301) ((?' ?E) ?\311) ((?' ?I) ?\315) ((?' ?O) ?\323)
      ((?' ?U) ?\332) ((?' ?Y) ?\335) ((?' ?a) ?\341) ((?' ?e) ?\351)
      ((?' ?i) ?\355) ((?' ?o) ?\363) ((?' ?u) ?\372) ((?' ?y) ?\375)
      ((?' ?') ?\264) ((?' ? ) ?') ((?` ?A) ?\300) ((?` ?E) ?\310)
      ((?` ?I) ?\314) ((?` ?O) ?\322) ((?` ?U) ?\331) ((?` ?a) ?\340)
      ((?` ?e) ?\350) ((?` ?i) ?\354) ((?` ?o) ?\362) ((?` ?u) ?\371)
      ((?` ? ) ?`) ((?` ?`) ?`) ((?^ ?A) ?\302) ((?^ ?E) ?\312)
      ((?^ ?I) ?\316) ((?^ ?O) ?\324) ((?^ ?U) ?\333) ((?^ ?a) ?\342)
      ((?^ ?e) ?\352) ((?^ ?i) ?\356) ((?^ ?o) ?\364) ((?^ ?u) ?\373)
      ((?^ ? ) ?^) ((?^ ?^) ?^) ((?\" ?A) ?\304) ((?\" ?E) ?\313)
      ((?\" ?I) ?\317) ((?\" ?O) ?\326) ((?\" ?U) ?\334) ((?\" ?a) ?\344)
      ((?\" ?e) ?\353) ((?\" ?i) ?\357) ((?\" ?o) ?\366) ((?\" ?s) ?\337)
      ((?\" ?u) ?\374) ((?\" ?y) ?\377) ((?\" ? ) ?\") ((?\" ?\") ?\250)
      ((?\~ ?A) ?\303) ((?\~ ?C) ?\307) ((?\~ ?D) ?\320) ((?\~ ?N) ?\321)
      ((?\~ ?O) ?\325) ((?\~ ?T) ?\336) ((?\~ ?a) ?\343) ((?\~ ?c) ?\347)
      ((?\~ ?d) ?\360) ((?\~ ?n) ?\361) ((?\~ ?o) ?\365) ((?\~ ?t) ?\376)
      ((?\~ ?>) ?\273) ((?\~ ?<) ?\253) ((?\~ ?\ ) ?\~) ((?\~ ?\~) ?\270)
      ((?\/ ?A) ?\305) ((?\/ ?E) ?\306) ((?\/ ?O) ?\330) ((?\/ ?a) ?\345)
      ((?\/ ?e) ?\346) ((?\/ ?o) ?\370) ((?\/ ?\ ) ?\/) ((?\/ ?\/) ?\260))))

  "List of language-specific customizations for the ISO Accents mode.

Each element of the list is of the form (LANGUAGE PREFIXES LIST).

LANGUAGE is a string naming the language.

PREFIXES is a list of characters that will be used as accent prefixes.
It is currently not used.

LIST is a list of accent translations.  It will be the value of the
`iso-accents-list' variable.")

(defvar iso-language nil
  "Language for which ISO Accents mode is currently customized.
Change it with the `iso-accents-customize' function.")

(defvar iso-accents-list nil
  "Association list for ISO accent combinations, for the chosen language.")

(defvar iso-accents-mode nil
  "*Non-nil enables ISO Accents mode.
Setting this variable makes it local to the current buffer.
See the function `iso-accents-mode'.")
(make-variable-buffer-local 'iso-accents-mode)

(defvar iso-accents-enable '(?' ?` ?^ ?\" ?~ ?/)
  "*List of accent keys that become prefixes in ISO Accents mode.
The default is (?' ?` ?^ ?\" ?~ ?/), which contains all the supported
accent keys.  If you set this variable to a list in which some of those
characters are missing, the missing ones do not act as accents.

Note that if you specify a language with `iso-accents-customize',
that can also turn off certain prefixes (whichever ones are not needed in
the language you choose).")

(defun iso-accents-accent-key (prompt)
  "Modify the following character by adding an accent to it."
  ;; Pick up the accent character.
  (if (and iso-accents-mode
	   (memq last-input-char iso-accents-enable))
      (iso-accents-compose prompt)
    (char-to-string last-input-char)))

(defun iso-accents-compose-key (prompt)
  "Modify the following character by adding an accent to it."
  ;; Pick up the accent character.
  (let ((combined (iso-accents-compose prompt)))
    (if unread-command-events
	(let ((unread unread-command-events))
	  (setq unread-command-events nil)
	  (error "Characters %s and %s cannot be composed"
		 (single-key-description (aref combined 0))
		 (single-key-description (car unread)))))
    combined))

(defun iso-accents-compose (prompt)
  (let* ((first-char last-input-char)
	 ;; Wait for the second key and look up the combination.
	 (second-char (if (or prompt
			      (not (eq (key-binding "a")
				       'self-insert-command))
			      ;; Called from anything but the command loop.
			      this-command)
			  (progn
			    (message "%s%c"
				     (or prompt "Compose with ")
				     first-char)
			    (read-event))
			(insert first-char)
			(prog1 (read-event)
			  (delete-region (1- (point)) (point)))))
	 (entry (assoc (list first-char second-char) iso-accents-list)))
    (if entry
	;; Found it: delete the first character and insert the combination.
	(concat (list (nth 1 entry)))
      ;; Otherwise, advance and schedule the second key for execution.
      (setq unread-command-events (list second-char))
      (vector first-char))))

;; It is a matter of taste if you want the minor mode indicated
;; in the mode line...
;; If so, uncomment the next four lines.
;; (or (assq 'iso-accents-mode minor-mode-map-alist)
;;     (setq minor-mode-alist
;; 	  (append minor-mode-alist
;; 		  '((iso-accents-mode " ISO-Acc")))))

;;;###autoload
(defun iso-accents-mode (&optional arg)
  "Toggle ISO Accents mode, in which accents modify the following letter.
This permits easy insertion of accented characters according to ISO-8859-1.
When Iso-accents mode is enabled, accent character keys
\(`, ', \", ^, / and ~) do not self-insert; instead, they modify the following
letter key so that it inserts an ISO accented letter.

You can customize ISO Accents mode to a particular language
with the command `iso-accents-customize'.

Special combinations: ~c gives a c with cedilla,
~d gives an Icelandic eth (d with dash).
~t gives an Icelandic thorn.
\"s gives German sharp s.
/a gives a with ring.
/e gives an a-e ligature.
~< and ~> give guillemots.
~! gives an inverted exclamation mark.
~? gives an inverted question mark.

With an argument, a positive argument enables ISO Accents mode, 
and a negative argument disables it."

  (interactive "P")

  (if (if arg
	  ;; Negative arg means switch it off.
	  (<= (prefix-numeric-value arg) 0)
	;; No arg means toggle.
	iso-accents-mode)
      (setq iso-accents-mode nil)

    ;; Enable electric accents.
    (setq iso-accents-mode t)))

(defun iso-accents-customize (language)
  "Customize the ISO accents machinery for a particular language.
It selects the customization based on the specifications in the
`iso-languages' variable."
  (interactive (list (completing-read "Language: " iso-languages nil t)))
  (let ((table (assoc language iso-languages))
	all-accents tail)
    (if (not table)
	(error "Unknown language")
      (setq iso-language language)
      (setq iso-accents-list (car (cdr (cdr table))))
      (if key-translation-map
	  (substitute-key-definition
	   'iso-accents-accent-key nil key-translation-map)
	(setq key-translation-map (make-sparse-keymap)))
      ;; Find all the characters that are used as accent prefixes
      ;; in this language, and set up translation for them.
      (setq tail iso-accents-list)
      (while tail
	(or (memq (car (car tail)) all-accents)
	    (setq all-accents (cons (car (car tail)) all-accents)))
	(setq tail (cdr tail)))
      (setq tail all-accents)
      (while tail
	(define-key key-translation-map (char-to-string (car tail))
	  'iso-accents-accent-key)
	(setq tail (cdr tail))))))

(defun iso-accentuate (start end)
  "Convert two-character sequences in region into accented characters.
Noninteractively, this operates on text from START to END.
This uses the same conversion that ISO Accents mode uses for type-in."
  (interactive "r")
  (save-excursion
    (save-restriction
      (narrow-to-region start end)
      (goto-char start)
      (forward-char 1)
      (let (entry)
	(while (< (point) end)
	  (if (and (memq (preceding-char) iso-accents-enable)
		   (<= ?A (following-char))
		   (<= (following-char) ?z)
		   (setq entry (assoc (list (preceding-char) (following-char))
				     iso-accents-list)))
	      (progn
		(forward-char -1)
		(delete-char 2)
		(insert (car (cdr entry)))
		(setq end (1- end)))
	    (forward-char 1)))))))

(defun iso-accent-rassoc-unit (value alist)
  (while (and alist
	      (not (eq (car (cdr (car alist))) value)))
    (setq alist (cdr alist)))
  (if alist
      (car alist)
    nil))

(defun iso-unaccentuate (start end)
  "Convert accented characters in the region into two-character sequences.
Noninteractively, this operates on text from START to END.
This uses the opposite of the conversion done by ISO Accents mode for type-in."
  (interactive "r")
  (save-excursion
    (save-restriction
      (narrow-to-region start end)
      (goto-char start)
      (let (entry)
	(while (< (point) end)
	  (if (and (> (following-char) 127)
		   (setq entry (iso-accent-rassoc-unit (following-char)
						       iso-accents-list)))
	      (progn
		(delete-char 1)
		(insert (car (car entry)) (car (cdr (car entry))))
		(setq end (1+ end)))
	    (forward-char 1)))))))

(defun iso-deaccentuate (start end)
  "Convert accented characters in the region into unaccented characters.
Noninteractively, this operates on text from START to END."
  (interactive "r")
  (save-excursion
    (save-restriction
      (narrow-to-region start end)
      (goto-char start)
      (let (entry)
	(while (< (point) end)
	  (if (and (> (following-char) 127)
		   (setq entry (iso-accent-rassoc-unit (following-char)
						       iso-accents-list)))
	      (progn
		(delete-char 1)
		(insert (car (cdr (car entry)))))
	    (forward-char 1)))))))

;; Set up the default settings.
(iso-accents-customize "default")

;;; iso-acc.el ends here