1 | ;;; mule-caesar.el --- ROT 13-47 Caesar rotation utility |
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2 | |
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3 | ;; Copyright (C) 1997,1998 Free Software Foundation, Inc. |
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4 | |
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5 | ;; Author: MORIOKA Tomohiko <morioka@jaist.ac.jp> |
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6 | ;; Keywords: ROT 13-47, caesar, mail, news, text/x-rot13-47 |
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7 | |
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8 | ;; This file is part of APEL (A Portable Emacs Library). |
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9 | |
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10 | ;; This program is free software; you can redistribute it and/or |
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11 | ;; modify it under the terms of the GNU General Public License as |
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12 | ;; published by the Free Software Foundation; either version 2, or (at |
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13 | ;; your option) any later version. |
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14 | |
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15 | ;; This program is distributed in the hope that it will be useful, but |
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16 | ;; WITHOUT ANY WARRANTY; without even the implied warranty of |
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17 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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18 | ;; General Public License for more details. |
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19 | |
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20 | ;; You should have received a copy of the GNU General Public License |
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21 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
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22 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
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23 | ;; Boston, MA 02111-1307, USA. |
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24 | |
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25 | ;;; Code: |
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26 | |
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27 | (require 'emu) ; for backward compatibility. |
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28 | (require 'poe) ; char-after. |
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29 | (require 'poem) ; charset-chars, char-charset, |
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30 | ; and split-char. |
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31 | |
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32 | (defun mule-caesar-region (start end &optional stride-ascii) |
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33 | "Caesar rotation of current region. |
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34 | Optional argument STRIDE-ASCII is rotation-size for Latin alphabet |
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35 | \(A-Z and a-z). For non-ASCII text, ROT-N/2 will be performed in any |
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36 | case (N=charset-chars; 94 for 94 or 94x94 graphic character set; 96 |
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37 | for 96 or 96x96 graphic character set)." |
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38 | (interactive "r\nP") |
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39 | (setq stride-ascii (if stride-ascii |
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40 | (mod stride-ascii 26) |
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41 | 13)) |
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42 | (save-excursion |
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43 | (save-restriction |
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44 | (narrow-to-region start end) |
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45 | (goto-char start) |
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46 | (while (< (point)(point-max)) |
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47 | (let* ((chr (char-after (point)))) |
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48 | (cond ((and (<= ?A chr) (<= chr ?Z)) |
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49 | (setq chr (+ chr stride-ascii)) |
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50 | (if (> chr ?Z) |
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51 | (setq chr (- chr 26)) |
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52 | ) |
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53 | (delete-char 1) |
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54 | (insert chr) |
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55 | ) |
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56 | ((and (<= ?a chr) (<= chr ?z)) |
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57 | (setq chr (+ chr stride-ascii)) |
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58 | (if (> chr ?z) |
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59 | (setq chr (- chr 26)) |
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60 | ) |
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61 | (delete-char 1) |
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62 | (insert chr) |
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63 | ) |
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64 | ((<= chr ?\x9f) |
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65 | (forward-char) |
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66 | ) |
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67 | (t |
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68 | (let* ((stride (lsh (charset-chars (char-charset chr)) -1)) |
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69 | (ret (mapcar (function |
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70 | (lambda (octet) |
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71 | (if (< octet 80) |
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72 | (+ octet stride) |
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73 | (- octet stride) |
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74 | ))) |
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75 | (cdr (split-char chr))))) |
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76 | (delete-char 1) |
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77 | (insert (make-char (char-charset chr) |
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78 | (car ret)(car (cdr ret)))) |
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79 | ))) |
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80 | ))))) |
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81 | |
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82 | |
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83 | (require 'product) |
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84 | (product-provide (provide 'mule-caesar) (require 'apel-ver)) |
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85 | |
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86 | ;;; mule-caesar.el ends here |
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