* fill-flowed.el: New file.

diff --git a/lisp/fill-flowed.el b/lisp/fill-flowed.el
new file mode 100644 (file)
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+++ b/lisp/fill-flowed.el
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+;;; fill-flowed.el --- interprete RFC2646 "flowed" text
+;; Copyright (C) 2000 Free Software Foundation, Inc.
+
+;; Author: Simon Josefsson <jas@pdc.kth.se>
+;; Keywords: mail
+
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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 this program; 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
+
+;; 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  commited to gnus cvs
+
+;;; Code:
+
+(eval-and-compile
+  (fset 'fill-flowed-point-at-bol
+       (if (fboundp 'point-at-bol)
+           'point-at-bol
+         'line-beginning-position))
+  
+  (fset '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)))
+         (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
+                       (backward-char 3)
+                       (looking-at "[^-][^-] "))
+                     (save-excursion
+                       (unless (eobp)
+                         (forward-char 1)
+                         (if quote
+                             (looking-at (format "^\\(%s\\)\\([^>]\\)" quote))
+                           (looking-at "^ ?")))))
+           (save-excursion
+             (replace-match (if (string= (match-string 2) " ")
+                                "" "\\2")))
+           (backward-delete-char -1)
+           (end-of-line))
+         (let ((fill-prefix (when quote (concat quote " "))))
+           (fill-region (fill-flowed-point-at-bol)
+                        (fill-flowed-point-at-eol)
+                        'left 'nosqueeze)))))))
+
+(provide 'fill-flowed)
+
+;;; fill-flowed.el ends here