4.3BSD/usr/contrib/emacs/lisp/fill.el
;; Fill commands for Emacs
;; Copyright (C) 1985 Richard M. Stallman.
;; This file is part of GNU Emacs.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY. No author or distributor
;; accepts responsibility to anyone for the consequences of using it
;; or for whether it serves any particular purpose or works at all,
;; unless he says so in writing. Refer to the GNU Emacs General Public
;; License for full details.
;; Everyone is granted permission to copy, modify and redistribute
;; GNU Emacs, but only under the conditions described in the
;; GNU Emacs General Public License. A copy of this license is
;; supposed to have been given to you along with GNU Emacs so you
;; can know your rights and responsibilities. It should be in a
;; file named COPYING. Among other things, the copyright notice
;; and this notice must be preserved on all copies.
(defun set-fill-prefix ()
"Set the fill-prefix to the current line up to point.
Filling expects lines to start with the fill prefix
and reinserts the fill prefix in each resulting line."
(interactive)
(setq fill-prefix (buffer-substring
(save-excursion (beginning-of-line) (point))
(point)))
(if (equal fill-prefix "")
(setq fill-prefix nil))
(if fill-prefix
(message "fill-prefix: \"%s\"" fill-prefix)
(message "fill-prefix cancelled")))
(defun fill-region-as-paragraph (from to &optional justify-flag)
"Fill region as one paragraph: break lines to fit fill-column.
Prefix arg means justify too.
From program, pass args FROM, TO and JUSTIFY-FLAG."
(interactive "r\nP")
(save-restriction
(narrow-to-region from to)
(goto-char (point-min))
(skip-chars-forward "\n")
(narrow-to-region (point) (point-max))
(let ((fpre (and fill-prefix (not (equal fill-prefix ""))
(regexp-quote fill-prefix))))
;; Delete the fill prefix from every line except the first.
;; The first line may not even have a fill prefix.
(and fpre
(progn
(goto-char (point-min))
(forward-line 1)
(while (not (eobp))
(if (looking-at fpre)
(delete-region (point) (match-end 0)))
(forward-line 1))))
(goto-char (point-min))
(and fpre (looking-at fpre) (forward-char (length fill-prefix))))
;; Make sure sentences ending at end of line get an extra space.
(goto-char (point-min))
(while (re-search-forward "[.?!][])""']*$" nil t)
(insert ? ))
;; The change all newlines to spaces.
(subst-char-in-region (point-min) (point-max) ?\n ?\ )
;; Flush excess spaces, except in the paragraph indentation.
(goto-char (point-min))
(skip-chars-forward " \t")
(while (re-search-forward " *" nil t)
(delete-region
(+ (match-beginning 0)
(if (save-excursion
(skip-chars-backward " ])\"'")
(memq (preceding-char) '(?. ?? ?!)))
2 1))
(match-end 0)))
(goto-char (point-max))
(delete-horizontal-space)
(insert " ")
(goto-char (point-min))
(let ((fplen (length (or fill-prefix ""))))
(while (not (eobp))
(move-to-column (1+ fill-column))
(if (eobp)
nil
(skip-chars-backward "^ \n")
(if (bolp)
(skip-chars-forward "^ \n")
(forward-char -1)))
(delete-horizontal-space)
(insert ?\n)
(and (not (eobp)) fill-prefix (not (equal fill-prefix ""))
(insert fill-prefix))
(and justify-flag (not (eobp))
(progn
(forward-line -1)
(justify-current-line)
(forward-line 1)))))))
(defun fill-paragraph (arg)
"Fill paragraph at or after point.
Prefix arg means justify as well."
(interactive "P")
(save-excursion
(forward-paragraph)
(or (bolp) (newline 1))
(let ((end (point)))
(backward-paragraph)
(fill-region-as-paragraph (point) end arg))))
(defun fill-region (from to &optional justify-flag)
"Fill each of the paragraphs in the region.
Prefix arg (non-nil third arg, if called from program)
means justify as well."
(interactive "r\nP")
(save-restriction
(narrow-to-region from to)
(goto-char (point-min))
(while (not (eobp))
(let ((initial (point))
(end (progn
(forward-paragraph 1) (point))))
(forward-paragraph -1)
(if (>= (point) initial)
(fill-region-as-paragraph (point) end justify-flag)
(goto-char end))))))
(defun justify-current-line ()
"Add spaces to line point is in, so it ends at fill-column."
(interactive)
(save-excursion
(save-restriction
(let (ncols beg)
(beginning-of-line)
(skip-chars-forward " \t")
(setq beg (point))
(end-of-line)
(narrow-to-region beg (point))
(goto-char beg)
(while (re-search-forward " *" nil t)
(delete-region
(+ (match-beginning 0)
(if (save-excursion
(skip-chars-backward " ])\"'")
(memq (preceding-char) '(?. ?? ?!)))
2 1))
(match-end 0)))
(goto-char beg)
(while (re-search-forward "[.?!][])""']*\n" nil t)
(forward-char -1)
(insert ? ))
(goto-char (point-max))
(setq ncols (- fill-column (current-column)))
(if (scan-buffer (point-min) 1 ? )
(while (> ncols 0)
(let ((nmove (+ 3 (% (random) 3))))
(while (> nmove 0)
(or (search-backward " " nil t)
(progn
(goto-char (point-max))
(search-backward " ")))
(skip-chars-backward " ")
(setq nmove (1- nmove))))
(insert " ")
(skip-chars-backward " ")
(setq ncols (1- ncols))))))))
(defun fill-individual-paragraphs (min max &optional justifyp mailp)
"Fill each paragraph in region according to its individual fill prefix.
Calling from a program, pass range to fill as first two arguments.
Optional third and fourth arguments JUSTIFY-FLAG and MAIL-FLAG:
JUSTIFY-FLAG to justify paragraphs (prefix arg),
MAIL-FLAG for a mail message, i. e. don't fill header lines."
(interactive "r\nP")
(let (fill-prefix)
(save-restriction
(save-excursion
(narrow-to-region min max)
(goto-char (point-min))
(while (progn
(skip-chars-forward " \t\n")
(not (eobp)))
(setq fill-prefix (buffer-substring (point) (progn (beginning-of-line) (point))))
(let ((fin (save-excursion (forward-paragraph) (point)))
(start (point)))
(if mailp
(while (re-search-forward "[ \t]*[^ \t\n]*:" fin t)
(forward-line 1)))
(cond ((= start (point))
(fill-region-as-paragraph (point) fin justifyp)
(goto-char fin)))))))))