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6594deb0 ER |
1 | ;;; life.el --- John Horton Conway's `Life' game for GNU Emacs |
2 | ||
5fd6d89f | 3 | ;; Copyright (C) 1988, 2001, 2002, 2003, 2004, |
5df4f04c | 4 | ;; 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. |
3a801d0c | 5 | |
4228277d | 6 | ;; Author: Kyle Jones <kyleuunet.uu.net> |
4127f015 | 7 | ;; Maintainer: FSF |
e9571d2a | 8 | ;; Keywords: games |
e5167999 | 9 | |
80a677d9 JA |
10 | ;; This file is part of GNU Emacs. |
11 | ||
b1fc2b50 | 12 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
80a677d9 | 13 | ;; it under the terms of the GNU General Public License as published by |
b1fc2b50 GM |
14 | ;; the Free Software Foundation, either version 3 of the License, or |
15 | ;; (at your option) any later version. | |
80a677d9 JA |
16 | |
17 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
18 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | ;; GNU General Public License for more details. | |
21 | ||
22 | ;; You should have received a copy of the GNU General Public License | |
b1fc2b50 | 23 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
80a677d9 | 24 | |
e41b2db1 ER |
25 | ;;; Commentary: |
26 | ||
27 | ;; A demonstrator for John Horton Conway's "Life" cellular automaton | |
28 | ;; in Emacs Lisp. Picks a random one of a set of interesting Life | |
eb8c3be9 | 29 | ;; patterns and evolves it according to the familiar rules. |
e41b2db1 | 30 | |
e5167999 ER |
31 | ;;; Code: |
32 | ||
4127f015 | 33 | (defvar life-patterns |
80a677d9 JA |
34 | [("@@@" " @@" "@@@") |
35 | ("@@@ @@@" "@@ @@ " "@@@ @@@") | |
36 | ("@@@ @@@" "@@ @@" "@@@ @@@") | |
37 | ("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@") | |
38 | ("@@@@@@@@@@") | |
39 | (" @@@@@@@@@@ " | |
40 | " @@@@@@@@@@ " | |
41 | " @@@@@@@@@@ " | |
42 | "@@@@@@@@@@ " | |
43 | "@@@@@@@@@@ ") | |
44 | ("@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@") | |
45 | ("@ @" "@ @" "@ @" | |
46 | "@ @" "@ @" "@ @" | |
47 | "@ @" "@ @" "@ @" | |
48 | "@ @" "@ @" "@ @" | |
49 | "@ @" "@ @" "@ @") | |
50 | ("@@ " " @@ " " @@ " | |
51 | " @@ " " @@ " " @@ " | |
52 | " @@ " " @@ " " @@ " | |
53 | " @@ " " @@ " " @@ " | |
54 | " @@ " " @@ " " @@ " | |
55 | " @@") | |
a1506d29 | 56 | ("@@@@@@@@@" "@ @ @" "@ @@@@@ @" "@ @ @ @" "@@@ @@@" |
5883afc5 JB |
57 | "@ @ @ @" "@ @@@@@ @" "@ @ @" "@@@@@@@@@") |
58 | (" @ " | |
59 | " @ @ " | |
60 | " @@ @@ @@" | |
61 | " @ @ @@ @@" | |
62 | "@@ @ @ @@ " | |
63 | "@@ @ @ @@ @ @ " | |
64 | " @ @ @ " | |
65 | " @ @ " | |
66 | " @@ ") | |
67 | (" @ " | |
68 | " @ @@" | |
69 | " @ @ " | |
70 | " @ " | |
71 | " @ " | |
72 | "@ @ ") | |
73 | ("@@@ @" | |
74 | "@ " | |
75 | " @@" | |
76 | " @@ @" | |
77 | "@ @ @") | |
78 | ("@@@@@@@@ @@@@@ @@@ @@@@@@@ @@@@@")] | |
80a677d9 JA |
79 | "Vector of rectangles containing some Life startup patterns.") |
80 | ||
81 | ;; Macros are used macros for manifest constants instead of variables | |
82 | ;; because the compiler will convert them to constants, which should | |
83 | ;; eval faster than symbols. | |
84 | ;; | |
80a677d9 JA |
85 | ;; Don't change any of the life-* macro constants unless you thoroughly |
86 | ;; understand the `life-grim-reaper' function. | |
e8a57935 JB |
87 | |
88 | (defmacro life-life-char () ?@) | |
89 | (defmacro life-death-char () (1+ (life-life-char))) | |
90 | (defmacro life-birth-char () 3) | |
91 | (defmacro life-void-char () ?\ ) | |
92 | ||
93 | (defmacro life-life-string () (char-to-string (life-life-char))) | |
94 | (defmacro life-death-string () (char-to-string (life-death-char))) | |
95 | (defmacro life-birth-string () (char-to-string (life-birth-char))) | |
96 | (defmacro life-void-string () (char-to-string (life-void-char))) | |
97 | (defmacro life-not-void-regexp () (concat "[^" (life-void-string) "\n]")) | |
98 | ||
44fad123 | 99 | (defmacro life-increment (variable) (list 'setq variable (list '1+ variable))) |
e8a57935 | 100 | |
80a677d9 JA |
101 | |
102 | ;; list of numbers that tell how many characters to move to get to | |
103 | ;; each of a cell's eight neighbors. | |
4127f015 | 104 | (defvar life-neighbor-deltas nil) |
80a677d9 JA |
105 | |
106 | ;; window display always starts here. Easier to deal with than | |
107 | ;; (scroll-up) and (scroll-down) when trying to center the display. | |
4127f015 | 108 | (defvar life-window-start nil) |
80a677d9 JA |
109 | |
110 | ;; For mode line | |
4127f015 | 111 | (defvar life-current-generation nil) |
80a677d9 | 112 | ;; Sadly, mode-line-format won't display numbers. |
4127f015 | 113 | (defvar life-generation-string nil) |
80a677d9 | 114 | |
44fad123 RS |
115 | (defvar life-initialized nil |
116 | "Non-nil if `life' has been run at least once.") | |
80a677d9 | 117 | |
e8a57935 | 118 | ;;;###autoload |
80a677d9 JA |
119 | (defun life (&optional sleeptime) |
120 | "Run Conway's Life simulation. | |
e3f99b91 JB |
121 | The starting pattern is randomly selected. Prefix arg (optional first |
122 | arg non-nil from a program) is the number of seconds to sleep between | |
80a677d9 JA |
123 | generations (this defaults to 1)." |
124 | (interactive "p") | |
44fad123 RS |
125 | (or life-initialized |
126 | (random t)) | |
127 | (setq life-initialized t) | |
80a677d9 JA |
128 | (or sleeptime (setq sleeptime 1)) |
129 | (life-setup) | |
e8a57935 JB |
130 | (catch 'life-exit |
131 | (while t | |
132 | (let ((inhibit-quit t)) | |
b0778a31 | 133 | (life-display-generation sleeptime) |
e8a57935 JB |
134 | (life-grim-reaper) |
135 | (life-expand-plane-if-needed) | |
b0778a31 | 136 | (life-increment-generation))))) |
80a677d9 | 137 | |
31e1d920 | 138 | (defalias 'life-mode 'life) |
80a677d9 JA |
139 | (put 'life-mode 'mode-class 'special) |
140 | ||
80a677d9 JA |
141 | (defun life-setup () |
142 | (let (n) | |
143 | (switch-to-buffer (get-buffer-create "*Life*") t) | |
144 | (erase-buffer) | |
145 | (kill-all-local-variables) | |
146 | (setq case-fold-search nil | |
147 | mode-name "Life" | |
148 | major-mode 'life-mode | |
149 | truncate-lines t | |
5883afc5 | 150 | show-trailing-whitespace nil |
80a677d9 JA |
151 | life-current-generation 0 |
152 | life-generation-string "0" | |
153 | mode-line-buffer-identification '("Life: generation " | |
154 | life-generation-string) | |
155 | fill-column (1- (window-width)) | |
156 | life-window-start 1) | |
157 | (buffer-disable-undo (current-buffer)) | |
158 | ;; stuff in the random pattern | |
159 | (life-insert-random-pattern) | |
160 | ;; make sure (life-life-char) is used throughout | |
44fad123 | 161 | (goto-char (point-min)) |
80a677d9 JA |
162 | (while (re-search-forward (life-not-void-regexp) nil t) |
163 | (replace-match (life-life-string) t t)) | |
164 | ;; center the pattern horizontally | |
44fad123 | 165 | (goto-char (point-min)) |
5ed619e0 | 166 | (setq n (/ (- fill-column (line-end-position)) 2)) |
80a677d9 JA |
167 | (while (not (eobp)) |
168 | (indent-to n) | |
169 | (forward-line)) | |
170 | ;; center the pattern vertically | |
171 | (setq n (/ (- (1- (window-height)) | |
172 | (count-lines (point-min) (point-max))) | |
173 | 2)) | |
44fad123 | 174 | (goto-char (point-min)) |
80a677d9 | 175 | (newline n) |
44fad123 | 176 | (goto-char (point-max)) |
80a677d9 JA |
177 | (newline n) |
178 | ;; pad lines out to fill-column | |
44fad123 | 179 | (goto-char (point-min)) |
80a677d9 JA |
180 | (while (not (eobp)) |
181 | (end-of-line) | |
182 | (indent-to fill-column) | |
183 | (move-to-column fill-column) | |
184 | (delete-region (point) (progn (end-of-line) (point))) | |
185 | (forward-line)) | |
186 | ;; expand tabs to spaces | |
187 | (untabify (point-min) (point-max)) | |
188 | ;; before starting be sure the automaton has room to grow | |
189 | (life-expand-plane-if-needed) | |
190 | ;; compute initial neighbor deltas | |
191 | (life-compute-neighbor-deltas))) | |
192 | ||
193 | (defun life-compute-neighbor-deltas () | |
194 | (setq life-neighbor-deltas | |
195 | (list -1 (- fill-column) | |
196 | (- (1+ fill-column)) (- (+ 2 fill-column)) | |
197 | 1 fill-column (1+ fill-column) | |
198 | (+ 2 fill-column)))) | |
199 | ||
200 | (defun life-insert-random-pattern () | |
201 | (insert-rectangle | |
6b6d5edf | 202 | (elt life-patterns (random (length life-patterns)))) |
80a677d9 JA |
203 | (insert ?\n)) |
204 | ||
205 | (defun life-increment-generation () | |
44fad123 | 206 | (life-increment life-current-generation) |
80a677d9 JA |
207 | (setq life-generation-string (int-to-string life-current-generation))) |
208 | ||
209 | (defun life-grim-reaper () | |
210 | ;; Clear the match information. Later we check to see if it | |
211 | ;; is still clear, if so then all the cells have died. | |
ac092f22 | 212 | (set-match-data nil) |
44fad123 | 213 | (goto-char (point-min)) |
80a677d9 JA |
214 | ;; For speed declare all local variable outside the loop. |
215 | (let (point char pivot living-neighbors list) | |
216 | (while (search-forward (life-life-string) nil t) | |
217 | (setq list life-neighbor-deltas | |
218 | living-neighbors 0 | |
219 | pivot (1- (point))) | |
220 | (while list | |
221 | (setq point (+ pivot (car list)) | |
222 | char (char-after point)) | |
223 | (cond ((eq char (life-void-char)) | |
224 | (subst-char-in-region point (1+ point) | |
225 | (life-void-char) 1 t)) | |
226 | ((< char 3) | |
227 | (subst-char-in-region point (1+ point) char (1+ char) t)) | |
228 | ((< char 9) | |
229 | (subst-char-in-region point (1+ point) char 9 t)) | |
230 | ((>= char (life-life-char)) | |
44fad123 | 231 | (life-increment living-neighbors))) |
80a677d9 JA |
232 | (setq list (cdr list))) |
233 | (if (memq living-neighbors '(2 3)) | |
234 | () | |
235 | (subst-char-in-region pivot (1+ pivot) | |
236 | (life-life-char) (life-death-char) t)))) | |
237 | (if (null (match-beginning 0)) | |
238 | (life-extinct-quit)) | |
239 | (subst-char-in-region 1 (point-max) 9 (life-void-char) t) | |
240 | (subst-char-in-region 1 (point-max) 1 (life-void-char) t) | |
241 | (subst-char-in-region 1 (point-max) 2 (life-void-char) t) | |
242 | (subst-char-in-region 1 (point-max) (life-birth-char) (life-life-char) t) | |
243 | (subst-char-in-region 1 (point-max) (life-death-char) (life-void-char) t)) | |
244 | ||
245 | (defun life-expand-plane-if-needed () | |
246 | (catch 'done | |
44fad123 | 247 | (goto-char (point-min)) |
80a677d9 JA |
248 | (while (not (eobp)) |
249 | ;; check for life at beginning or end of line. If found at | |
250 | ;; either end, expand at both ends, | |
251 | (cond ((or (eq (following-char) (life-life-char)) | |
252 | (eq (progn (end-of-line) (preceding-char)) (life-life-char))) | |
44fad123 | 253 | (goto-char (point-min)) |
80a677d9 JA |
254 | (while (not (eobp)) |
255 | (insert (life-void-char)) | |
256 | (end-of-line) | |
257 | (insert (life-void-char)) | |
258 | (forward-char)) | |
259 | (setq fill-column (+ 2 fill-column)) | |
260 | (scroll-left 1) | |
261 | (life-compute-neighbor-deltas) | |
262 | (throw 'done t))) | |
263 | (forward-line))) | |
44fad123 | 264 | (goto-char (point-min)) |
80a677d9 JA |
265 | ;; check for life within the first two lines of the buffer. |
266 | ;; If present insert two lifeless lines at the beginning.. | |
267 | (cond ((search-forward (life-life-string) | |
268 | (+ (point) fill-column fill-column 2) t) | |
44fad123 | 269 | (goto-char (point-min)) |
80a677d9 JA |
270 | (insert-char (life-void-char) fill-column) |
271 | (insert ?\n) | |
272 | (insert-char (life-void-char) fill-column) | |
273 | (insert ?\n) | |
274 | (setq life-window-start (+ life-window-start fill-column 1)))) | |
44fad123 | 275 | (goto-char (point-max)) |
80a677d9 JA |
276 | ;; check for life within the last two lines of the buffer. |
277 | ;; If present insert two lifeless lines at the end. | |
278 | (cond ((search-backward (life-life-string) | |
279 | (- (point) fill-column fill-column 2) t) | |
44fad123 | 280 | (goto-char (point-max)) |
80a677d9 JA |
281 | (insert-char (life-void-char) fill-column) |
282 | (insert ?\n) | |
283 | (insert-char (life-void-char) fill-column) | |
284 | (insert ?\n) | |
285 | (setq life-window-start (+ life-window-start fill-column 1))))) | |
286 | ||
287 | (defun life-display-generation (sleeptime) | |
288 | (goto-char life-window-start) | |
289 | (recenter 0) | |
a1506d29 | 290 | |
e8a57935 | 291 | ;; Redisplay; if the user has hit a key, exit the loop. |
33aba6a0 EZ |
292 | (or (and (sit-for sleeptime) (< 0 sleeptime)) |
293 | (not (input-pending-p)) | |
e8a57935 | 294 | (throw 'life-exit nil))) |
80a677d9 JA |
295 | |
296 | (defun life-extinct-quit () | |
297 | (life-display-generation 0) | |
298 | (signal 'life-extinct nil)) | |
299 | ||
300 | (put 'life-extinct 'error-conditions '(life-extinct quit)) | |
301 | (put 'life-extinct 'error-message "All life has perished") | |
49116ac0 JB |
302 | |
303 | (provide 'life) | |
304 | ||
6594deb0 | 305 | ;;; life.el ends here |