X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/acaf905b1130aae80fa59d2c861ffd4c8eb75486..97d44922da3c22b3973f95892bfa2ee4afc0ceac:/lisp/play/life.el

diff --git a/lisp/play/life.el b/lisp/play/life.el
index e9133f8486..5bf8a9b57b 100644
--- a/lisp/play/life.el
+++ b/lisp/play/life.el
@@ -1,9 +1,9 @@
 ;;; life.el --- John Horton Conway's `Life' game for GNU Emacs
 
-;; Copyright (C) 1988, 2001-2012  Free Software Foundation, Inc.
+;; Copyright (C) 1988, 2001-2015 Free Software Foundation, Inc.
 
 ;; Author: Kyle Jones <kyleuunet.uu.net>
-;; Maintainer: FSF
+;; Maintainer: emacs-devel@gnu.org
 ;; Keywords: games
 
 ;; This file is part of GNU Emacs.
@@ -111,9 +111,6 @@
 ;; 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.
@@ -121,40 +118,36 @@ 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))
+      (let ((inhibit-quit t)
+	    (inhibit-read-only 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)
+(define-derived-mode life-mode special-mode "Life"
+  "Major mode for the buffer of `life'."
+  (setq-local case-fold-search nil)
+  (setq-local truncate-lines t)
+  (setq-local show-trailing-whitespace nil)
+  (setq-local life-current-generation 0)
+  (setq-local life-generation-string "0")
+  (setq-local mode-line-buffer-identification '("Life: generation "
+                                                life-generation-string))
+  (setq-local fill-column (1- (window-width)))
+  (setq-local life-window-start 1)
+  (buffer-disable-undo))
 
 (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
+  (switch-to-buffer (get-buffer-create "*Life*") t)
+  (erase-buffer)
+  (life-mode)
+  ;; stuff in the random pattern
+  (let ((inhibit-read-only t))
     (life-insert-random-pattern)
     ;; make sure (life-life-char) is used throughout
     (goto-char (point-min))
@@ -162,18 +155,18 @@ generations (this defaults to 1)."
       (replace-match (life-life-string) t t))
     ;; center the pattern horizontally
     (goto-char (point-min))
-    (setq n (/ (- fill-column (line-end-position)) 2))
-    (while (not (eobp))
-      (indent-to n)
-      (forward-line))
+    (let ((n (/ (- fill-column (line-end-position)) 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)
+    (let ((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))
@@ -296,8 +289,7 @@ generations (this defaults to 1)."
   (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")
+(define-error 'life-extinct "All life has perished" 'quit) ;FIXME: quit really?
 
 (provide 'life)