lisp/textmodes/paragraphs.el

   1 ;; Paragraph and sentence parsing.
   2 ;; Copyright (C) 1985-1991 Free Software Foundation, Inc.
   3
   4 ;; This file is part of GNU Emacs.
   5
   6 ;; GNU Emacs is free software; you can redistribute it and/or modify
   7 ;; it under the terms of the GNU General Public License as published by
   8 ;; the Free Software Foundation; either version 1, or (at your option)
   9 ;; any later version.
  10
  11 ;; GNU Emacs is distributed in the hope that it will be useful,
  12 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ;; GNU General Public License for more details.
  15
  16 ;; You should have received a copy of the GNU General Public License
  17 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  18 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  19
  20
  21 ;;;###autoload (defconst paragraph-start "^[ \t\n\f]"
  22 ;;;###autoload   "*Regexp for beginning of a line that starts OR separates paragraphs.")
  23
  24 ;;;###autoload (defconst paragraph-separate "^[ \t\f]*$"
  25 ;;;###autoload   "*Regexp for beginning of a line that separates paragraphs.
  26 ;;;###autoload If you change this, you may have to change paragraph-start also.")
  27
  28 ;;;###autoload (defconst sentence-end   (purecopy "[.?!][]\"')}]*\\($\\| $\\|\t\\|  \\)[ \t\n]*") "\
  29 ;;;###autoload *Regexp describing the end of a sentence.
  30 ;;;###autoload All paragraph boundaries also end sentences, regardless.")
  31
  32 ;;;###autoload (defconst page-delimiter "^\014" "\
  33 ;;;###autoload *Regexp describing line-beginnings that separate pages.")
  34
  35 ;;;###autoload (defvar paragraph-ignore-fill-prefix nil
  36 ;;;###autoload   "Non-nil means the paragraph commands are not affected by `fill-prefix'.
  37 ;;;###autoload This is desirable in modes where blank lines are the paragraph delimiters.")
  38
  39
  40 (defun forward-paragraph (&optional arg)
  41   "Move forward to end of paragraph.
  42 With arg N, do it N times; negative arg -N means move forward N paragraphs.
  43
  44 A line which `paragraph-start' matches either separates paragraphs
  45 \(if `paragraph-separate' matches it also) or is the first line of a paragraph.
  46 A paragraph end is the beginning of a line which is not part of the paragraph
  47 to which the end of the previous line belongs, or the end of the buffer."
  48   (interactive "p")
  49   (or arg (setq arg 1))
  50   (let* ((fill-prefix-regexp
  51           (and fill-prefix (not (equal fill-prefix ""))
  52                (not paragraph-ignore-fill-prefix)
  53                (regexp-quote fill-prefix)))
  54          (paragraph-separate
  55           (if fill-prefix-regexp
  56               (concat paragraph-separate "\\|^"
  57                       fill-prefix-regexp "[ \t]*$")
  58             paragraph-separate)))
  59     (while (< arg 0)
  60       (if (and (not (looking-at paragraph-separate))
  61                (re-search-backward "^\n" (max (1- (point)) (point-min)) t))
  62           nil
  63         (forward-char -1) (beginning-of-line)
  64         (while (and (not (bobp)) (looking-at paragraph-separate))
  65           (forward-line -1))
  66         (end-of-line)
  67         ;; Search back for line that starts or separates paragraphs.
  68         (if (if fill-prefix-regexp
  69                 ;; There is a fill prefix; it overrides paragraph-start.
  70                 (progn
  71                  (while (progn (beginning-of-line)
  72                                (and (not (bobp))
  73                                     (not (looking-at paragraph-separate))
  74                                     (looking-at fill-prefix-regexp)))
  75                    (forward-line -1))
  76                  (not (bobp)))
  77               (re-search-backward paragraph-start nil t))
  78             ;; Found one.
  79             (progn
  80               (while (and (not (eobp)) (looking-at paragraph-separate))
  81                 (forward-line 1))
  82               (if (eq (char-after (- (point) 2)) ?\n)
  83                   (forward-line -1)))
  84           ;; No starter or separator line => use buffer beg.
  85           (goto-char (point-min))))
  86       (setq arg (1+ arg)))
  87     (while (> arg 0)
  88       (beginning-of-line)
  89       (while (prog1 (and (not (eobp))
  90                          (looking-at paragraph-separate))
  91                     (forward-line 1)))
  92       (if fill-prefix-regexp
  93           ;; There is a fill prefix; it overrides paragraph-start.
  94           (while (and (not (eobp))
  95                       (not (looking-at paragraph-separate))
  96                       (looking-at fill-prefix-regexp))
  97             (forward-line 1))
  98         (if (re-search-forward paragraph-start nil t)
  99             (goto-char (match-beginning 0))
 100           (goto-char (point-max))))
 101       (setq arg (1- arg)))))
 102
 103 (defun backward-paragraph (&optional arg)
 104   "Move backward to start of paragraph.
 105 With arg N, do it N times; negative arg -N means move forward N paragraphs.
 106
 107 A paragraph start is the beginning of a line which is a
 108 `first-line-of-paragraph' or which is ordinary text and follows a
 109 paragraph-separating line; except: if the first real line of a
 110 paragraph is preceded by a blank line, the paragraph starts at that
 111 blank line.
 112
 113 See `forward-paragraph' for more information."
 114   (interactive "p")
 115   (or arg (setq arg 1))
 116   (forward-paragraph (- arg)))
 117
 118 (defun mark-paragraph ()
 119   "Put point at beginning of this paragraph, mark at end.
 120 The paragraph marked is the one that contains point or follows point."
 121   (interactive)
 122   (forward-paragraph 1)
 123   (push-mark nil t)
 124   (backward-paragraph 1))
 125
 126 (defun kill-paragraph (arg)
 127   "Kill forward to end of paragraph.
 128 With arg N, kill forward to Nth end of paragraph;
 129 negative arg -N means kill backward to Nth start of paragraph."
 130   (interactive "p")
 131   (kill-region (point) (progn (forward-paragraph arg) (point))))
 132
 133 (defun backward-kill-paragraph (arg)
 134   "Kill back to start of paragraph.
 135 With arg N, kill back to Nth start of paragraph;
 136 negative arg -N means kill forward to Nth end of paragraph."
 137   (interactive "p")
 138   (kill-region (point) (progn (backward-paragraph arg) (point))))
 139
 140 (defun transpose-paragraphs (arg)
 141   "Interchange this (or next) paragraph with previous one."
 142   (interactive "*p")
 143   (transpose-subr 'forward-paragraph arg))
 144
 145 (defun start-of-paragraph-text ()
 146   (let ((opoint (point)) npoint)
 147     (forward-paragraph -1)
 148     (setq npoint (point))
 149     (skip-chars-forward " \t\n")
 150     ;; If the range of blank lines found spans the original start point,
 151     ;; try again from the beginning of it.
 152     ;; Must be careful to avoid infinite loop
 153     ;; when following a single return at start of buffer.
 154     (if (and (>= (point) opoint) (< npoint opoint))
 155         (progn
 156           (goto-char npoint)
 157           (if (> npoint (point-min))
 158               (start-of-paragraph-text))))))
 159
 160 (defun end-of-paragraph-text ()
 161   (let ((opoint (point)))
 162     (forward-paragraph 1)
 163     (if (eq (preceding-char) ?\n) (forward-char -1))
 164     (if (<= (point) opoint)
 165         (progn
 166           (forward-char 1)
 167           (if (< (point) (point-max))
 168               (end-of-paragraph-text))))))
 169
 170 (defun forward-sentence (&optional arg)
 171   "Move forward to next`sentence-end'.  With argument, repeat.
 172 With negative argument, move backward repeatedly to `sentence-beginning'.
 173
 174 The variable `sentence-end' is a regular expression that matches ends of
 175 sentences.  Also, every paragraph boundary terminates sentences as well."
 176   (interactive "p")
 177   (or arg (setq arg 1))
 178   (while (< arg 0)
 179     (let ((par-beg (save-excursion (start-of-paragraph-text) (point))))
 180       (if (re-search-backward (concat sentence-end "[^ \t\n]") par-beg t)
 181           (goto-char (1- (match-end 0)))
 182         (goto-char par-beg)))
 183     (setq arg (1+ arg)))
 184   (while (> arg 0)
 185     (let ((par-end (save-excursion (end-of-paragraph-text) (point))))
 186       (if (re-search-forward sentence-end par-end t)
 187           (skip-chars-backward " \t\n")
 188         (goto-char par-end)))
 189     (setq arg (1- arg))))
 190
 191 (defun backward-sentence (&optional arg)
 192   "Move backward to start of sentence.  With arg, do it arg times.
 193 See `forward-sentence' for more information."
 194   (interactive "p")
 195   (or arg (setq arg 1))
 196   (forward-sentence (- arg)))
 197
 198 (defun kill-sentence (&optional arg)
 199   "Kill from point to end of sentence.
 200 With arg, repeat; negative arg -N means kill back to Nth start of sentence."
 201   (interactive "*p")
 202   (let ((beg (point)))
 203     (forward-sentence arg)
 204     (kill-region beg (point))))
 205
 206 (defun backward-kill-sentence (&optional arg)
 207   "Kill back from point to start of sentence.
 208 With arg, repeat, or kill forward to Nth end of sentence if negative arg -N."
 209   (interactive "*p")
 210   (let ((beg (point)))
 211     (backward-sentence arg)
 212     (kill-region beg (point))))
 213
 214 (defun mark-end-of-sentence (arg)
 215   "Put mark at end of sentence.  Arg works as in `forward-sentence'."
 216   (interactive "p")
 217   (push-mark
 218     (save-excursion
 219       (forward-sentence arg)
 220       (point))))
 221
 222 (defun transpose-sentences (arg)
 223   "Interchange this (next) and previous sentence."
 224   (interactive "*p")
 225   (transpose-subr 'forward-sentence arg))