[plt-scheme] Question result is not true or false: (void)

From: Jayto (igotjats at gmail.com)
Date: Sun Dec 27 12:51:22 EST 2009

I am trying to design a sudokku game in dr scheme, but it is proving
difficult.
First what I did was draw out the game with this code:
[code]
(define (d x)
  (display x)
  )
(display "     1      2      3      4      5      6      7      8
9")
(newline)
(display "
#___________________________________________________________#")
(newline)
(display "A  | ")(d "x")(d "      x")(d "      x")(d "  ||")(d "  6")
(d "      x")(d "      8")(d "  ||") (d "  7")(d "      9")(d "
1") (d " |")

(newline)(display "   |")(d "                  ||
||                  |")
(newline)

(display "B  | ")(d "5")(d "      8")(d "      6")(d "  ||")
(d "  x")

(d "      9")(d "      1")(d "  ||") (d "  4")(d "      3")(d "
2") (d " |")


(newline)(display "   |")(d "                  ||
||                  |")
(newline)

(display "C  | ")(d "x")(d "      1")(d "      7")(d "  ||")(d "  x")
(d "      x")(d "      x")(d "  ||") (d "  6")(d "      5")(d "
8") (d " |")

(newline)(display "   |")(d "==================||===================||
==================|")
(newline)

(display "D  | ")(d "1")(d "      x")(d "      9")(d "  ||")(d "  3")
(d "      x")(d "      6")(d "  ||") (d "  x")(d "      8")(d "
7") (d " |")

(newline)(display "   |")(d "                  ||
||                  |")
(newline)

(display "E  | ")(d "2")(d "      6")(d "      3")(d "  ||")(d "  5")
(d "      8")(d "      7")(d "  ||") (d "  x")(d "      1")(d "
4") (d " |")

(newline)(display "   |")(d "                  ||
||                  |")
(newline)

(display "F  | ")(d "8")(d "      7")(d "      x")(d "  ||")(d "  9")
(d "      x")(d "      4")(d "  ||") (d "  3")(d "      2")(d "
6") (d " |")

(newline)(display "   |")(d "==================||===================||
==================|")
(newline)

(display "G  | ")(d "6")(d "      5")(d "      x")(d "  ||")(d "  8")
(d "      x")(d "      x")(d "  ||") (d "  1")(d "      x")(d "
3") (d " |")

(newline)(display "   |")(d "                  ||
||                  |")
(newline)

(display "H  | ")(d "7")(d "      x")(d "      8")(d "  ||")(d "  1")
(d "      x")(d "      x")(d "  ||") (d "  x")(d "      6")(d "
5") (d " |")

(newline)(display "   |")(d "                  ||
||                  |")
(newline)

(display "I  | ")(d "4")(d "      3")(d "      x")(d "  ||")(d "  x")
(d "      6")(d "      x")(d "  ||") (d "  x")(d "      x")(d "
x") (d " |")
(newline)
(display "
#-----------------------------------------------------------#")
(newline)
[/code]


I had an idea on how to make the game actually work.It would require
every line to have its own condition like so:
[code]
(define (draw-game x)
  (cond
    [(= x 1) (and (display "     1      2      3      4      5
6      7      8      9") (doit (+ x 1)))]
    [(= x 2)(and  (newline) (doit (+ x 1)))]
    [(= x 3) (and (display "
#___________________________________________________________#")(doit
(+ x 1)))]
    )
  )
[/code]



Why can't I use the conditional like I did above?
I get this error [code] and: question result is not true or false:
(void) [/code]
Is there another way I could get the game working?


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