;;; life.el --- John Horton Conway's `Life' game for GNU Emacs
-;; Copyright (C) 1988 Free Software Foundation, Inc.
+;; Copyright (C) 1988, 2001, 2002, 2003, 2004,
+;; 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
-;; Author: Kyle Jones <talos!kjones@uunet.uu.net>
-;; Keyword: games
+;; 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 2, or (at your option)
+;; the Free Software Foundation; either version 3, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING. If not, write to
-;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+;; along with GNU Emacs; see the file COPYING. If not, write to the
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
+
+;;; 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:
-(defconst life-patterns
+(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.
;;
-;; The (require) wrapping forces the compiler to eval these macros at
-;; compile time. This would not be necessary if we did not use macros
-;; inside of macros, which the compiler doesn't seem to check for.
-;;
;; Don't change any of the life-* macro constants unless you thoroughly
;; understand the `life-grim-reaper' function.
-(require
- (progn
- (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]"))
-
- ;; try to optimize the (goto-char (point-min)) & (goto-char (point-max))
- ;; idioms. This depends on goto-char's not griping if we underrshoot
- ;; or overshoot beginning or end of buffer.
- (defmacro goto-beginning-of-buffer () '(goto-char 1))
- (defmacro maxint () (lsh (lsh (lognot 0) 1) -1))
- (defmacro goto-end-of-buffer () '(goto-char (maxint)))
-
- (defmacro increment (variable) (list 'setq variable (list '1+ variable)))
- 'life))
+
+(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.
-(defconst life-neighbor-deltas nil)
+(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.
-(defconst life-window-start nil)
+(defvar life-window-start nil)
;; For mode line
-(defconst life-current-generation nil)
+(defvar life-current-generation nil)
;; Sadly, mode-line-format won't display numbers.
-(defconst life-generation-string nil)
+(defvar life-generation-string nil)
-(defun abs (n) (if (< n 0) (- n) n))
+(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)
- (life-display-generation sleeptime)
- (while t
- (let ((inhibit-quit t))
- (life-grim-reaper)
- (life-expand-plane-if-needed)
- (life-increment-generation)
- (life-display-generation sleeptime))))
-
-(fset 'life-mode 'life)
-(put 'life-mode 'mode-class 'special)
+ (catch 'life-exit
+ (while t
+ (let ((inhibit-quit t))
+ (life-display-generation sleeptime)
+ (life-grim-reaper)
+ (life-expand-plane-if-needed)
+ (life-increment-generation)))))
-(random t)
+(defalias 'life-mode 'life)
+(put 'life-mode 'mode-class 'special)
(defun life-setup ()
(let (n)
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 "
;; stuff in the random pattern
(life-insert-random-pattern)
;; make sure (life-life-char) is used throughout
- (goto-beginning-of-buffer)
+ (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-beginning-of-buffer)
+ (goto-char (point-min))
(setq n (/ (- fill-column (save-excursion (end-of-line) (point))) 2))
(while (not (eobp))
(indent-to n)
(setq n (/ (- (1- (window-height))
(count-lines (point-min) (point-max)))
2))
- (goto-beginning-of-buffer)
+ (goto-char (point-min))
(newline n)
- (goto-end-of-buffer)
+ (goto-char (point-max))
(newline n)
;; pad lines out to fill-column
- (goto-beginning-of-buffer)
+ (goto-char (point-min))
(while (not (eobp))
(end-of-line)
(indent-to fill-column)
(defun life-insert-random-pattern ()
(insert-rectangle
- (elt life-patterns (% (abs (random)) (length life-patterns))))
+ (elt life-patterns (random (length life-patterns))))
(insert ?\n))
(defun life-increment-generation ()
- (increment life-current-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.
- (store-match-data nil)
- (goto-beginning-of-buffer)
+ (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)
((< char 9)
(subst-char-in-region point (1+ point) char 9 t))
((>= char (life-life-char))
- (increment living-neighbors)))
+ (life-increment living-neighbors)))
(setq list (cdr list)))
(if (memq living-neighbors '(2 3))
()
(defun life-expand-plane-if-needed ()
(catch 'done
- (goto-beginning-of-buffer)
+ (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-beginning-of-buffer)
+ (goto-char (point-min))
(while (not (eobp))
(insert (life-void-char))
(end-of-line)
(life-compute-neighbor-deltas)
(throw 'done t)))
(forward-line)))
- (goto-beginning-of-buffer)
+ (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-beginning-of-buffer)
+ (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-end-of-buffer)
+ (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-end-of-buffer)
+ (goto-char (point-max))
(insert-char (life-void-char) fill-column)
(insert ?\n)
(insert-char (life-void-char) fill-column)
(defun life-display-generation (sleeptime)
(goto-char life-window-start)
(recenter 0)
- (sit-for sleeptime))
+
+ ;; 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)
(provide 'life)
+;; arch-tag: e9373544-755e-42f5-a9a1-4d4c422bb97a
;;; life.el ends here
HCoop / bpt / emacs.git / blobdiff