Cracker Barrel Game Solution

Hi Everyone,

I am very new to Scheme and I am trying to tackle the Cracker Barrel Pegboard Game. I found a website that has some example code, but I cant seem to get it to work. When I try to run it, I get an "Unbound variable: null" error.

The files I am running are located here:
http://www.computingbook.org/list-procedures.ss
http://www.computingbook.org/pegboard.ss

You need both files to run it.

The instructions on how to use it are here: http://www.computingbook.org/ch5-data.pdf, but I can't get it to run. I keep getting the above error.

I am evaluating (solve-pegboard (board- remove-peg (make-board 5) (make-position 1 1)))


Any help would be greatly appreciated. I have been pounding my head all day, trying to figure this out. Or if you know of any confirmed working code, that would be great too.

Thanks in advance!

The author appears to be using some slightly non-standard symbols, but nothing that is not easily corrected.

Try defining the following equivalents before running the code:

(define null nil)
(define true #t)
(define false #f)