1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
|
;;; life.el --- John Horton Conway's `Life' game for GNU Emacs
;; Copyright (C) 1988, 2001, 2002, 2003, 2004,
;; 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
;; Author: Kyle Jones <kyleuunet.uu.net>
;; Maintainer: FSF
;; Keywords: games
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;; A demonstrator for John Horton Conway's "Life" cellular automaton
;; in Emacs Lisp. Picks a random one of a set of interesting Life
;; patterns and evolves it according to the familiar rules.
;;; Code:
(defvar life-patterns
[("@@@" " @@" "@@@")
("@@@ @@@" "@@ @@ " "@@@ @@@")
("@@@ @@@" "@@ @@" "@@@ @@@")
("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@")
("@@@@@@@@@@")
(" @@@@@@@@@@ "
" @@@@@@@@@@ "
" @@@@@@@@@@ "
"@@@@@@@@@@ "
"@@@@@@@@@@ ")
("@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@" "@")
("@ @" "@ @" "@ @"
"@ @" "@ @" "@ @"
"@ @" "@ @" "@ @"
"@ @" "@ @" "@ @"
"@ @" "@ @" "@ @")
("@@ " " @@ " " @@ "
" @@ " " @@ " " @@ "
" @@ " " @@ " " @@ "
" @@ " " @@ " " @@ "
" @@ " " @@ " " @@ "
" @@")
("@@@@@@@@@" "@ @ @" "@ @@@@@ @" "@ @ @ @" "@@@ @@@"
"@ @ @ @" "@ @@@@@ @" "@ @ @" "@@@@@@@@@")
(" @ "
" @ @ "
" @@ @@ @@"
" @ @ @@ @@"
"@@ @ @ @@ "
"@@ @ @ @@ @ @ "
" @ @ @ "
" @ @ "
" @@ ")
(" @ "
" @ @@"
" @ @ "
" @ "
" @ "
"@ @ ")
("@@@ @"
"@ "
" @@"
" @@ @"
"@ @ @")
("@@@@@@@@ @@@@@ @@@ @@@@@@@ @@@@@")]
"Vector of rectangles containing some Life startup patterns.")
;; Macros are used macros for manifest constants instead of variables
;; because the compiler will convert them to constants, which should
;; eval faster than symbols.
;;
;; Don't change any of the life-* macro constants unless you thoroughly
;; understand the `life-grim-reaper' function.
(defmacro life-life-char () ?@)
(defmacro life-death-char () (1+ (life-life-char)))
(defmacro life-birth-char () 3)
(defmacro life-void-char () ?\ )
(defmacro life-life-string () (char-to-string (life-life-char)))
(defmacro life-death-string () (char-to-string (life-death-char)))
(defmacro life-birth-string () (char-to-string (life-birth-char)))
(defmacro life-void-string () (char-to-string (life-void-char)))
(defmacro life-not-void-regexp () (concat "[^" (life-void-string) "\n]"))
(defmacro life-increment (variable) (list 'setq variable (list '1+ variable)))
;; list of numbers that tell how many characters to move to get to
;; each of a cell's eight neighbors.
(defvar life-neighbor-deltas nil)
;; window display always starts here. Easier to deal with than
;; (scroll-up) and (scroll-down) when trying to center the display.
(defvar life-window-start nil)
;; For mode line
(defvar life-current-generation nil)
;; Sadly, mode-line-format won't display numbers.
(defvar life-generation-string nil)
(defvar life-initialized nil
"Non-nil if `life' has been run at least once.")
;;;###autoload
(defun life (&optional sleeptime)
"Run Conway's Life simulation.
The starting pattern is randomly selected. Prefix arg (optional first
arg non-nil from a program) is the number of seconds to sleep between
generations (this defaults to 1)."
(interactive "p")
(or life-initialized
(random t))
(setq life-initialized t)
(or sleeptime (setq sleeptime 1))
(life-setup)
(catch 'life-exit
(while t
(let ((inhibit-quit t))
(life-display-generation sleeptime)
(life-grim-reaper)
(life-expand-plane-if-needed)
(life-increment-generation)))))
(defalias 'life-mode 'life)
(put 'life-mode 'mode-class 'special)
(defun life-setup ()
(let (n)
(switch-to-buffer (get-buffer-create "*Life*") t)
(erase-buffer)
(kill-all-local-variables)
(setq case-fold-search nil
mode-name "Life"
major-mode 'life-mode
truncate-lines t
show-trailing-whitespace nil
life-current-generation 0
life-generation-string "0"
mode-line-buffer-identification '("Life: generation "
life-generation-string)
fill-column (1- (window-width))
life-window-start 1)
(buffer-disable-undo (current-buffer))
;; stuff in the random pattern
(life-insert-random-pattern)
;; make sure (life-life-char) is used throughout
(goto-char (point-min))
(while (re-search-forward (life-not-void-regexp) nil t)
(replace-match (life-life-string) t t))
;; center the pattern horizontally
(goto-char (point-min))
(setq n (/ (- fill-column (save-excursion (end-of-line) (point))) 2))
(while (not (eobp))
(indent-to n)
(forward-line))
;; center the pattern vertically
(setq n (/ (- (1- (window-height))
(count-lines (point-min) (point-max)))
2))
(goto-char (point-min))
(newline n)
(goto-char (point-max))
(newline n)
;; pad lines out to fill-column
(goto-char (point-min))
(while (not (eobp))
(end-of-line)
(indent-to fill-column)
(move-to-column fill-column)
(delete-region (point) (progn (end-of-line) (point)))
(forward-line))
;; expand tabs to spaces
(untabify (point-min) (point-max))
;; before starting be sure the automaton has room to grow
(life-expand-plane-if-needed)
;; compute initial neighbor deltas
(life-compute-neighbor-deltas)))
(defun life-compute-neighbor-deltas ()
(setq life-neighbor-deltas
(list -1 (- fill-column)
(- (1+ fill-column)) (- (+ 2 fill-column))
1 fill-column (1+ fill-column)
(+ 2 fill-column))))
(defun life-insert-random-pattern ()
(insert-rectangle
(elt life-patterns (random (length life-patterns))))
(insert ?\n))
(defun life-increment-generation ()
(life-increment life-current-generation)
(setq life-generation-string (int-to-string life-current-generation)))
(defun life-grim-reaper ()
;; Clear the match information. Later we check to see if it
;; is still clear, if so then all the cells have died.
(set-match-data nil)
(goto-char (point-min))
;; For speed declare all local variable outside the loop.
(let (point char pivot living-neighbors list)
(while (search-forward (life-life-string) nil t)
(setq list life-neighbor-deltas
living-neighbors 0
pivot (1- (point)))
(while list
(setq point (+ pivot (car list))
char (char-after point))
(cond ((eq char (life-void-char))
(subst-char-in-region point (1+ point)
(life-void-char) 1 t))
((< char 3)
(subst-char-in-region point (1+ point) char (1+ char) t))
((< char 9)
(subst-char-in-region point (1+ point) char 9 t))
((>= char (life-life-char))
(life-increment living-neighbors)))
(setq list (cdr list)))
(if (memq living-neighbors '(2 3))
()
(subst-char-in-region pivot (1+ pivot)
(life-life-char) (life-death-char) t))))
(if (null (match-beginning 0))
(life-extinct-quit))
(subst-char-in-region 1 (point-max) 9 (life-void-char) t)
(subst-char-in-region 1 (point-max) 1 (life-void-char) t)
(subst-char-in-region 1 (point-max) 2 (life-void-char) t)
(subst-char-in-region 1 (point-max) (life-birth-char) (life-life-char) t)
(subst-char-in-region 1 (point-max) (life-death-char) (life-void-char) t))
(defun life-expand-plane-if-needed ()
(catch 'done
(goto-char (point-min))
(while (not (eobp))
;; check for life at beginning or end of line. If found at
;; either end, expand at both ends,
(cond ((or (eq (following-char) (life-life-char))
(eq (progn (end-of-line) (preceding-char)) (life-life-char)))
(goto-char (point-min))
(while (not (eobp))
(insert (life-void-char))
(end-of-line)
(insert (life-void-char))
(forward-char))
(setq fill-column (+ 2 fill-column))
(scroll-left 1)
(life-compute-neighbor-deltas)
(throw 'done t)))
(forward-line)))
(goto-char (point-min))
;; check for life within the first two lines of the buffer.
;; If present insert two lifeless lines at the beginning..
(cond ((search-forward (life-life-string)
(+ (point) fill-column fill-column 2) t)
(goto-char (point-min))
(insert-char (life-void-char) fill-column)
(insert ?\n)
(insert-char (life-void-char) fill-column)
(insert ?\n)
(setq life-window-start (+ life-window-start fill-column 1))))
(goto-char (point-max))
;; check for life within the last two lines of the buffer.
;; If present insert two lifeless lines at the end.
(cond ((search-backward (life-life-string)
(- (point) fill-column fill-column 2) t)
(goto-char (point-max))
(insert-char (life-void-char) fill-column)
(insert ?\n)
(insert-char (life-void-char) fill-column)
(insert ?\n)
(setq life-window-start (+ life-window-start fill-column 1)))))
(defun life-display-generation (sleeptime)
(goto-char life-window-start)
(recenter 0)
;; Redisplay; if the user has hit a key, exit the loop.
(or (and (sit-for sleeptime) (< 0 sleeptime))
(not (input-pending-p))
(throw 'life-exit nil)))
(defun life-extinct-quit ()
(life-display-generation 0)
(signal 'life-extinct nil))
(put 'life-extinct 'error-conditions '(life-extinct quit))
(put 'life-extinct 'error-message "All life has perished")
(provide 'life)
;; arch-tag: e9373544-755e-42f5-a9a1-4d4c422bb97a
;;; life.el ends here
|
