[bpt/emacs.git] / lisp / gnus / flow-fill.el

;;; flow-fill.el --- interprete RFC2646 "flowed" text

;; Copyright (C) 2000, 2002 Free Software Foundation, Inc.

;; Author: Simon Josefsson <jas@pdc.kth.se>
;; Keywords: mail

;; 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:

;; This implement decoding of RFC2646 formatted text, including the
;; quoted-depth wins rules.

;; Theory of operation: search for lines ending with SPC, save quote
;; length of line, remove SPC and concatenate line with the following
;; line if quote length of following line matches current line.

;; When no further concatenations are possible, we've found a
;; paragraph and we let `fill-region' fill the long line into several
;; lines with the quote prefix as `fill-prefix'.

;; Todo: encoding, implement basic `fill-region' (Emacs and XEmacs
;;       implementations differ..)

;; History:

;; 2000-02-17  posted on ding mailing list
;; 2000-02-19  use `point-at-{b,e}ol' in XEmacs
;; 2000-03-11  no compile warnings for point-at-bol stuff
;; 2000-03-26  committed to gnus cvs
;; 2000-10-23  don't flow "-- " lines, make "quote-depth wins" rule
;;             work when first line is at level 0.

;;; Code:

(eval-when-compile (require 'cl))

(eval-and-compile
  (defalias 'fill-flowed-point-at-bol
	(if (fboundp 'point-at-bol)
	    'point-at-bol
	  'line-beginning-position))

   (defalias 'fill-flowed-point-at-eol
	(if (fboundp 'point-at-eol)
	    'point-at-eol
	  'line-end-position)))

(defun fill-flowed (&optional buffer)
  (save-excursion
    (set-buffer (or (current-buffer) buffer))
    (goto-char (point-min))
    (while (re-search-forward " $" nil t)
      (when (save-excursion
	      (beginning-of-line)
	      (looking-at "^\\(>*\\)\\( ?\\)"))
	(let ((quote (match-string 1)) sig)
	  (if (string= quote "")
	      (setq quote nil))
	  (when (and quote (string= (match-string 2) ""))
	    (save-excursion
	      ;; insert SP after quote for pleasant reading of quoted lines
	      (beginning-of-line)
	      (when (> (skip-chars-forward ">") 0)
		(insert " "))))
	  (while (and (save-excursion
			(ignore-errors (backward-char 3))
			(setq sig (looking-at "-- "))
			(looking-at "[^-][^-] "))
		      (save-excursion
			(unless (eobp)
			  (forward-char 1)
			  (looking-at (format "^\\(%s\\)\\([^>]\\)" (or quote " ?"))))))
	    (save-excursion
	      (replace-match (if (string= (match-string 2) " ")
				 "" "\\2")))
	    (backward-delete-char -1)
	    (end-of-line))
	  (unless sig
	    (let ((fill-prefix (when quote (concat quote " "))))
	      (fill-region (fill-flowed-point-at-bol)
			   (fill-flowed-point-at-eol)
			   'left 'nosqueeze))))))))

(provide 'flow-fill)

;;; arch-tag: addc0040-bc53-4f17-b4bc-1eb44eed6f0b
;;; flow-fill.el ends here
Commit	Line	Data
c113de23 GM	1	;;; flow-fill.el --- interprete RFC2646 "flowed" text
c113de23 GM	2
8f688cb0	3	;; Copyright (C) 2000, 2002 Free Software Foundation, Inc.
c113de23 GM	4
	5	;; Author: Simon Josefsson <jas@pdc.kth.se>
	6	;; Keywords: mail
	7
	8	;; This file is part of GNU Emacs.
	9
	10	;; GNU Emacs is free software; you can redistribute it and/or modify
	11	;; it under the terms of the GNU General Public License as published by
	12	;; the Free Software Foundation; either version 2, or (at your option)
	13	;; any later version.
	14
	15	;; GNU Emacs is distributed in the hope that it will be useful,
	16	;; but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	;; GNU General Public License for more details.
	19
	20	;; You should have received a copy of the GNU General Public License
	21	;; along with GNU Emacs; see the file COPYING. If not, write to the
	22	;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	23	;; Boston, MA 02111-1307, USA.
	24
	25	;;; Commentary:
	26
	27	;; This implement decoding of RFC2646 formatted text, including the
	28	;; quoted-depth wins rules.
	29
	30	;; Theory of operation: search for lines ending with SPC, save quote
	31	;; length of line, remove SPC and concatenate line with the following
	32	;; line if quote length of following line matches current line.
	33
	34	;; When no further concatenations are possible, we've found a
	35	;; paragraph and we let `fill-region' fill the long line into several
	36	;; lines with the quote prefix as `fill-prefix'.
	37
01b5d73b DL	38	;; Todo: encoding, implement basic `fill-region' (Emacs and XEmacs
01b5d73b DL	39	;; implementations differ..)
c113de23 GM	40
	41	;; History:
	42
	43	;; 2000-02-17 posted on ding mailing list
	44	;; 2000-02-19 use `point-at-{b,e}ol' in XEmacs
	45	;; 2000-03-11 no compile warnings for point-at-bol stuff
8f688cb0	46	;; 2000-03-26 committed to gnus cvs
01b5d73b DL	47	;; 2000-10-23 don't flow "-- " lines, make "quote-depth wins" rule
01b5d73b DL	48	;; work when first line is at level 0.
c113de23 GM	49
	50	;;; Code:
	51
01b5d73b DL	52	(eval-when-compile (require 'cl))
01b5d73b DL	53
c113de23 GM	54	(eval-and-compile
	55	(defalias 'fill-flowed-point-at-bol
	56	(if (fboundp 'point-at-bol)
	57	'point-at-bol
	58	'line-beginning-position))
01b5d73b DL	59
01b5d73b DL	60	(defalias 'fill-flowed-point-at-eol
c113de23 GM	61	(if (fboundp 'point-at-eol)
	62	'point-at-eol
	63	'line-end-position)))
	64
	65	(defun fill-flowed (&optional buffer)
	66	(save-excursion
	67	(set-buffer (or (current-buffer) buffer))
	68	(goto-char (point-min))
	69	(while (re-search-forward " $" nil t)
	70	(when (save-excursion
	71	(beginning-of-line)
	72	(looking-at "^\\(>*\\)\\( ?\\)"))
01b5d73b	73	(let ((quote (match-string 1)) sig)
c113de23 GM	74	(if (string= quote "")
	75	(setq quote nil))
	76	(when (and quote (string= (match-string 2) ""))
	77	(save-excursion
	78	;; insert SP after quote for pleasant reading of quoted lines
	79	(beginning-of-line)
	80	(when (> (skip-chars-forward ">") 0)
	81	(insert " "))))
	82	(while (and (save-excursion
01b5d73b DL	83	(ignore-errors (backward-char 3))
01b5d73b DL	84	(setq sig (looking-at "-- "))
c113de23 GM	85	(looking-at "[^-][^-] "))
	86	(save-excursion
	87	(unless (eobp)
	88	(forward-char 1)
01b5d73b	89	(looking-at (format "^\\(%s\\)\\([^>]\\)" (or quote " ?"))))))
c113de23 GM	90	(save-excursion
	91	(replace-match (if (string= (match-string 2) " ")
	92	"" "\\2")))
	93	(backward-delete-char -1)
	94	(end-of-line))
01b5d73b DL	95	(unless sig
	96	(let ((fill-prefix (when quote (concat quote " "))))
	97	(fill-region (fill-flowed-point-at-bol)
	98	(fill-flowed-point-at-eol)
	99	'left 'nosqueeze))))))))
c113de23 GM	100
	101	(provide 'flow-fill)
	102
ab5796a9	103	;;; arch-tag: addc0040-bc53-4f17-b4bc-1eb44eed6f0b
c113de23	104	;;; flow-fill.el ends here