lisp/play/dissociate.el

   1 ;;; dissociate.el --- scramble text amusingly for Emacs.
   2
   3 ;; Copyright (C) 1985 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6 ;; Keywords: games
   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 ;; The single entry point, `dissociated-press', applies a travesty
  28 ;; generator to the current buffer.  The results can be quite amusing.
  29
  30 ;;; Code:
  31
  32 ;;;###autoload
  33 (defun dissociated-press (&optional arg)
  34   "Dissociate the text of the current buffer.
  35 Output goes in buffer named *Dissociation*,
  36 which is redisplayed each time text is added to it.
  37 Every so often the user must say whether to continue.
  38 If ARG is positive, require ARG chars of continuity.
  39 If ARG is negative, require -ARG words of continuity.
  40 Default is 2."
  41   (interactive "P")
  42   (setq arg (if arg (prefix-numeric-value arg) 2))
  43   (let* ((inbuf (current-buffer))
  44          (outbuf (get-buffer-create "*Dissociation*"))
  45          (move-function (if (> arg 0) 'forward-char 'forward-word))
  46          (move-amount (if (> arg 0) arg (- arg)))
  47          (search-function (if (> arg 0) 'search-forward 'word-search-forward))
  48          (last-query-point 0))
  49     (if (= (point-max) (point-min))
  50         (error "The buffer contains no text to start from"))
  51     (switch-to-buffer outbuf)
  52     (erase-buffer)
  53     (while
  54       (save-excursion
  55         (goto-char last-query-point)
  56         (vertical-motion (- (window-height) 4))
  57         (or (= (point) (point-max))
  58             (and (progn (goto-char (point-max))
  59                         (y-or-n-p "Continue dissociation? "))
  60                  (progn
  61                    (message "")
  62                    (recenter 1)
  63                    (setq last-query-point (point-max))
  64                    t))))
  65       (let (start end)
  66         (save-excursion
  67          (set-buffer inbuf)
  68          (setq start (point))
  69          (if (eq move-function 'forward-char)
  70              (progn
  71                (setq end (+ start (+ move-amount (random 16))))
  72                (if (> end (point-max))
  73                    (setq end (+ 1 move-amount (random 16))))
  74                (goto-char end))
  75            (funcall move-function
  76                     (+ move-amount (random 16))))
  77          (setq end (point)))
  78         (let ((opoint (point)))
  79           (insert-buffer-substring inbuf start end)
  80           (save-excursion
  81            (goto-char opoint)
  82            (end-of-line)
  83            (and (> (current-column) fill-column)
  84                 (do-auto-fill)))))
  85       (save-excursion
  86        (set-buffer inbuf)
  87        (if (eobp)
  88            (goto-char (point-min))
  89          (let ((overlap
  90                 (buffer-substring (prog1 (point)
  91                                          (funcall move-function
  92                                                   (- move-amount)))
  93                                   (point))))
  94            (goto-char (1+ (random (1- (point-max)))))
  95            (or (funcall search-function overlap nil t)
  96                (let ((opoint (point)))
  97                  (goto-char 1)
  98                  (funcall search-function overlap opoint t))))))
  99       (sit-for 0))))
 100
 101 ;;; dissociate.el ends here