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354 lines
13 KiB
EmacsLisp
354 lines
13 KiB
EmacsLisp
;;; fill.el --- fill commands for Emacs
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;; Copyright (C) 1985, 1986, 1992 Free Software Foundation, Inc.
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;; Keywords: wp
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;; This file is part of GNU Emacs.
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;; GNU Emacs is free software; you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation; either version 2, or (at your option)
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;; any later version.
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;; GNU Emacs is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;; GNU General Public License for more details.
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;; You should have received a copy of the GNU General Public License
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;; along with GNU Emacs; see the file COPYING. If not, write to
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;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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;;; Commentary:
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;; All the commands for filling text. These are documented in the Emacs
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;; manual.
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;;; Code:
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(defconst fill-individual-varying-indent nil
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"*Controls criterion for a new paragraph in `fill-individual-paragraphs'.
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Non-nil means changing indent doesn't end a paragraph.
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That mode can handle paragraphs with extra indentation on the first line,
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but it requires separator lines between paragraphs.
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Nil means that any change in indentation starts a new paragraph.")
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(defun set-fill-prefix ()
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"Set the fill-prefix to the current line up to point.
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Filling expects lines to start with the fill prefix and
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reinserts the fill prefix in each resulting line."
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(interactive)
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(setq fill-prefix (buffer-substring
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(save-excursion (beginning-of-line) (point))
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(point)))
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(if (equal fill-prefix "")
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(setq fill-prefix nil))
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(if fill-prefix
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(message "fill-prefix: \"%s\"" fill-prefix)
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(message "fill-prefix cancelled")))
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(defconst adaptive-fill-mode t
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"*Non-nil means determine a paragraph's fill prefix from its text.")
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(defconst adaptive-fill-regexp "[ \t]*\\([>*] +\\)?"
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"*Regexp to match text at start of line that constitutes indentation.
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If Adaptive Fill mode is enabled, whatever text matches this pattern
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on the second line of a paragraph is used as the standard indentation
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for the paragraph.")
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(defun fill-region-as-paragraph (from to &optional justify-flag)
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"Fill region as one paragraph: break lines to fit fill-column.
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Prefix arg means justify too.
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From program, pass args FROM, TO and JUSTIFY-FLAG."
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(interactive "r\nP")
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;; Arrange for undoing the fill to restore point.
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(if (and buffer-undo-list (not (eq buffer-undo-list t)))
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(setq buffer-undo-list (cons (point) buffer-undo-list)))
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;; Don't let Adaptive Fill mode alter the fill prefix permanently.
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(let ((fill-prefix fill-prefix))
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;; Figure out how this paragraph is indented, if desired.
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(if (and adaptive-fill-mode
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(or (null fill-prefix) (string= fill-prefix "")))
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(save-excursion
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(goto-char (min from to))
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(if (eolp) (forward-line 1))
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(forward-line 1)
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(if (< (point) (max from to))
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(let ((start (point)))
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(re-search-forward adaptive-fill-regexp)
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(setq fill-prefix (buffer-substring start (point))))
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(goto-char (min from to))
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(if (eolp) (forward-line 1))
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;; If paragraph has only one line, don't assume
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;; that additional lines would have the same starting
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;; decoration. Assume no indentation.
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;; (re-search-forward adaptive-fill-regexp)
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;; (setq fill-prefix (make-string (current-column) ?\ ))
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)))
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(save-restriction
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(narrow-to-region from to)
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(goto-char (point-min))
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(skip-chars-forward "\n")
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(narrow-to-region (point) (point-max))
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(setq from (point))
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(goto-char (point-max))
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(let ((fpre (and fill-prefix (not (equal fill-prefix ""))
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(regexp-quote fill-prefix))))
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;; Delete the fill prefix from every line except the first.
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;; The first line may not even have a fill prefix.
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(and fpre
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(progn
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(if (>= (length fill-prefix) fill-column)
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(error "fill-prefix too long for specified width"))
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(goto-char (point-min))
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(forward-line 1)
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(while (not (eobp))
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(if (looking-at fpre)
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(delete-region (point) (match-end 0)))
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(forward-line 1))
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(goto-char (point-min))
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(and (looking-at fpre) (forward-char (length fill-prefix)))
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(setq from (point)))))
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;; from is now before the text to fill,
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;; but after any fill prefix on the first line.
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;; Make sure sentences ending at end of line get an extra space.
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;; loses on split abbrevs ("Mr.\nSmith")
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(goto-char from)
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(while (re-search-forward "[.?!][])}\"']*$" nil t)
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(insert ? ))
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;; Then change all newlines to spaces.
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(subst-char-in-region from (point-max) ?\n ?\ )
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;; Flush excess spaces, except in the paragraph indentation.
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(goto-char from)
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(skip-chars-forward " \t")
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;; nuke tabs while we're at it; they get screwed up in a fill
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;; this is quick, but loses when a sole tab follows the end of a sentence.
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;; actually, it is difficult to tell that from "Mr.\tSmith".
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;; blame the typist.
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(subst-char-in-region (point) (point-max) ?\t ?\ )
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(while (re-search-forward " *" nil t)
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(delete-region
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(+ (match-beginning 0)
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(if (save-excursion
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(skip-chars-backward " ]})\"'")
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(memq (preceding-char) '(?. ?? ?!)))
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2 1))
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(match-end 0)))
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(goto-char (point-max))
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(delete-horizontal-space)
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(insert " ")
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(goto-char (point-min))
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;; This is the actual filling loop.
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(let ((prefixcol 0) linebeg)
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(while (not (eobp))
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(setq linebeg (point))
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(move-to-column (1+ fill-column))
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(if (eobp)
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nil
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;; Move back to start of word.
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(skip-chars-backward "^ \n" linebeg)
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;; Don't break after a period followed by just one space.
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;; Move back to the previous place to break.
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;; The reason is that if a period ends up at the end of a line,
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;; further fills will assume it ends a sentence.
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;; If we now know it does not end a sentence,
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;; avoid putting it at the end of the line.
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(while (and (> (point) (+ linebeg 2))
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(eq (preceding-char) ?\ )
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(eq (char-after (- (point) 2)) ?\.))
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(forward-char -2)
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(skip-chars-backward "^ \n" linebeg))
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(if (if (zerop prefixcol) (bolp) (>= prefixcol (current-column)))
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;; Keep at least one word even if fill prefix exceeds margin.
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;; This handles all but the first line of the paragraph.
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(progn
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(skip-chars-forward " ")
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(skip-chars-forward "^ \n"))
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;; Normally, move back over the single space between the words.
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(forward-char -1)))
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(if (and fill-prefix (zerop prefixcol)
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(< (- (point) (point-min)) (length fill-prefix))
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(string= (buffer-substring (point-min) (point))
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(substring fill-prefix 0 (- (point) (point-min)))))
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;; Keep at least one word even if fill prefix exceeds margin.
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;; This handles the first line of the paragraph.
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(progn
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(skip-chars-forward " ")
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(skip-chars-forward "^ \n")))
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;; Replace all whitespace here with one newline.
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;; Insert before deleting, so we don't forget which side of
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;; the whitespace point or markers used to be on.
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(skip-chars-backward " ")
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(insert ?\n)
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(delete-horizontal-space)
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;; Insert the fill prefix at start of each line.
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;; Set prefixcol so whitespace in the prefix won't get lost.
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(and (not (eobp)) fill-prefix (not (equal fill-prefix ""))
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(progn
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(insert fill-prefix)
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(setq prefixcol (current-column))))
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;; Justify the line just ended, if desired.
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(and justify-flag (not (eobp))
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(progn
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(forward-line -1)
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(justify-current-line)
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(forward-line 1))))))))
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(defun fill-paragraph (arg)
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"Fill paragraph at or after point. Prefix arg means justify as well."
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(interactive "P")
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(let ((before (point)))
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(save-excursion
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(forward-paragraph)
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(or (bolp) (newline 1))
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(let ((end (point))
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(beg (progn (backward-paragraph) (point))))
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(goto-char before)
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(fill-region-as-paragraph beg end arg)))))
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(defun fill-region (from to &optional justify-flag)
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"Fill each of the paragraphs in the region.
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Prefix arg (non-nil third arg, if called from program) means justify as well."
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(interactive "r\nP")
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(save-restriction
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(narrow-to-region from to)
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(goto-char (point-min))
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(while (not (eobp))
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(let ((initial (point))
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(end (progn
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(forward-paragraph 1) (point))))
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(forward-paragraph -1)
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(if (>= (point) initial)
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(fill-region-as-paragraph (point) end justify-flag)
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(goto-char end))))))
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(defun justify-current-line ()
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"Add spaces to line point is in, so it ends at `fill-column'."
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(interactive)
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(save-excursion
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(save-restriction
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(let (ncols beg indent)
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(beginning-of-line)
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(forward-char (length fill-prefix))
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(skip-chars-forward " \t")
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(setq indent (current-column))
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(setq beg (point))
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(end-of-line)
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(narrow-to-region beg (point))
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(goto-char beg)
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(while (re-search-forward " *" nil t)
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(delete-region
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(+ (match-beginning 0)
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(if (save-excursion
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(skip-chars-backward " ])\"'")
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(memq (preceding-char) '(?. ?? ?!)))
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2 1))
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(match-end 0)))
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(goto-char beg)
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(while (re-search-forward "[.?!][])\"']*\n" nil t)
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(forward-char -1)
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(insert ? ))
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(goto-char (point-max))
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;; Note that the buffer bounds start after the indentation,
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;; so the columns counted by INDENT don't appear in (current-column).
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(setq ncols (- fill-column (current-column) indent))
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(if (search-backward " " nil t)
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(while (> ncols 0)
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(let ((nmove (+ 3 (random 3))))
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(while (> nmove 0)
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(or (search-backward " " nil t)
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(progn
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(goto-char (point-max))
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(search-backward " ")))
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(skip-chars-backward " ")
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(setq nmove (1- nmove))))
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(insert " ")
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(skip-chars-backward " ")
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(setq ncols (1- ncols)))))))
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nil)
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(defun fill-nonuniform-paragraphs (min max &optional justifyp mailp)
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"Fill paragraphs within the region, allowing varying indentation within each.
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This command divides the region into \"paragraphs\",
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only at paragraph-separator lines, then fills each paragraph
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using as the fill prefix the smallest indentation of any line
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in the paragraph.
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When calling from a program, pass range to fill as first two arguments.
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Optional third and fourth arguments JUSTIFY-FLAG and MAIL-FLAG:
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JUSTIFY-FLAG to justify paragraphs (prefix arg),
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MAIL-FLAG for a mail message, i. e. don't fill header lines."
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(interactive "r\nP")
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(let ((fill-individual-varying-indent t))
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(fill-individual-paragraphs min max justifyp mailp)))
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(defun fill-individual-paragraphs (min max &optional justifyp mailp)
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"Fill paragraphs of uniform indentation within the region.
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This command divides the region into \"paragraphs\",
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treating every change in indentation level as a paragraph boundary,
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then fills each paragraph using its indentation level as the fill prefix.
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When calling from a program, pass range to fill as first two arguments.
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Optional third and fourth arguments JUSTIFY-FLAG and MAIL-FLAG:
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JUSTIFY-FLAG to justify paragraphs (prefix arg),
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MAIL-FLAG for a mail message, i. e. don't fill header lines."
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(interactive "r\nP")
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(save-restriction
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(save-excursion
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(goto-char min)
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(beginning-of-line)
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(if mailp
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(while (or (looking-at "[ \t]*[^ \t\n]*:") (looking-at "[ \t]*$"))
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(search-forward "\n\n" nil 'move)))
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(narrow-to-region (point) max)
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;; Loop over paragraphs.
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(while (progn (skip-chars-forward " \t\n") (not (eobp)))
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(beginning-of-line)
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(let ((start (point))
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fill-prefix fill-prefix-regexp)
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;; Find end of paragraph, and compute the smallest fill-prefix
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;; that fits all the lines in this paragraph.
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(while (progn
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;; Update the fill-prefix on the first line
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;; and whenever the prefix good so far is too long.
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(if (not (and fill-prefix
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(looking-at fill-prefix-regexp)))
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(setq fill-prefix
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(buffer-substring (point)
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(save-excursion (skip-chars-forward " \t") (point)))
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fill-prefix-regexp
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(regexp-quote fill-prefix)))
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(forward-line 1)
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;; Now stop the loop if end of paragraph.
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(and (not (eobp))
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(if fill-individual-varying-indent
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;; If this line is a separator line, with or
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;; without prefix, end the paragraph.
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(and
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(not (looking-at paragraph-separate))
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(save-excursion
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(not (and (looking-at fill-prefix-regexp)
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(progn (forward-char (length fill-prefix))
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(looking-at paragraph-separate))))))
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;; If this line has more or less indent
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;; than the fill prefix wants, end the paragraph.
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(and (looking-at fill-prefix-regexp)
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(save-excursion
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(not (progn (forward-char (length fill-prefix))
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(or (looking-at paragraph-separate)
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(looking-at paragraph-start))))))))))
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;; Fill this paragraph, but don't add a newline at the end.
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(let ((had-newline (bolp)))
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(fill-region-as-paragraph start (point) justifyp)
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(or had-newline (delete-char -1))))))))
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;;; fill.el ends here
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