X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=src%2Ftest%2Fhanoi.lisp;h=7a25656c06e1a7e5903d8921e5e311ffb19a5954;hp=0c4bfca5cfb077b4f5d69ca6133bac8312d0c06a;hb=daa06c8dedc6dc1cf21936ee2769d9d25f0567bd;hpb=13a4d451b903d08e52005bcf531efa8de351bf2b

diff --git a/src/test/hanoi.lisp b/src/test/hanoi.lisp
index 0c4bfca5..7a25656c 100644
--- a/src/test/hanoi.lisp
+++ b/src/test/hanoi.lisp
@@ -1,3 +1,22 @@
+;
+; Towers of Hanoi
+;
+; Copyright © 2016 Keith Packard <keithp@keithp.com>
+;
+; This program 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 of the License, or
+; (at your option) any later version.
+;
+; This program 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.
+;
+
+
+; ANSI control sequences
+
 (defun move-to (col row)
   (patom "\033[" row ";" col "H" nil)
   )
@@ -6,17 +25,24 @@
   (patom "\033[2J" nil)
   )
 
-(setq stack '("*" "**" "***" "****" "*****" "******" "*******"))
-
-(setq top (+ (length stack) 3))
-
-(setq stacks nil)
-
 (defun display-string (x y str)
   (move-to x y)
   (patom str)
   )
 
+; Here's the pieces to display
+
+(setq stack '("     *     " "    ***    " "   *****   " "  *******  " " ********* " "***********"))
+
+;
+; Here's all of the stacks of pieces
+; This is generated when the program is run
+;
+(setq stacks nil)
+
+; Display one stack, clearing any
+; space above it
+
 (defun display-stack (x y clear stack)
   (cond ((= 0 clear)
 	 (cond (stack (progn
@@ -27,23 +53,22 @@
 	       )
 	 )
 	(t (progn
-	     (display-string x y "          ")
+	     (display-string x y "                    ")
 	     (display-stack x (1+ y) (1- clear) stack)
 	     )
 	   )
 	)
   )
 
-(defun length (list)
-  (cond (list (1+ (length (cdr list))))
-	(0)
-	)
-  )
+; Position of the top of the stack on the screen
+; Shorter stacks start further down the screen
 
 (defun stack-pos (y stack)
   (- y (length stack))
   )
 
+; Display all of the stacks, spaced 20 columns apart
+
 (defun display-stacks (x y stacks)
   (cond (stacks (progn
 		  (display-stack x 0 (stack-pos y (car stacks)) (car stacks))
@@ -52,32 +77,36 @@
 	)
   )
 
+; Display all of the stacks, then move the cursor
+; out of the way and flush the output
+
 (defun display ()
   (display-stacks 0 top stacks)
   (move-to 1 21)
   (flush)
   )
 
-(defun length (l)
-  (cond (l (1+ (length (cdr l)))) (0))
-  )
+; Reset stacks to the starting state, with
+; all of the pieces in the first stack and the
+; other two empty
 
 (defun reset-stacks ()
   (setq stacks (list stack nil nil))
+  (setq top (+ (length stack) 3))
   (length stack)
   )
 
+; more functions which could usefully
+; be in the rom image
+
 (defun min (a b)
   (cond ((< a b) a)
 	(b)
 	)
   )
 
-(defun nth (list n)
-  (cond ((= n 0) (car list))
-	((nth (cdr list) (1- n)))
-	)
-  )
+; Replace a stack in the list of stacks
+; with a new value
 
 (defun replace (list pos member)
   (cond ((= pos 0) (cons member (cdr list)))
@@ -85,6 +114,9 @@
 	)
   )
 
+; Move a piece from the top of one stack
+; to the top of another
+
 (defun move-piece (from to)
   (let ((from-stack (nth stacks from))
 	(to-stack (nth stacks to))
@@ -94,10 +126,12 @@
     (setq stacks (replace stacks from from-stack))
     (setq stacks (replace stacks to to-stack))
     (display)
-    (delay 100)
+;    (delay 100)
     )
   )
 
+; The implementation of the game
+
 (defun _hanoi (n from to use)
   (cond ((= 1 n)
 	 (progn
@@ -114,8 +148,22 @@
 	)
   )
 
+; A pretty interface which
+; resets the state of the game,
+; clears the screen and runs
+; the program
+
 (defun hanoi ()
   (setq len (reset-stacks))
   (clear)
   (_hanoi len 0 1 2)
   )
+
+(defun hanois(n)
+  (while (> n 0)
+    (progn
+      (hanoi)
+      (setq l (1- l))
+      )
+    )
+  )