Fixed next and back

Author: zmactep

strats/stdgame.clj

@@ -2,7 +2,7 @@
 (def LEFT 1)
 (def DOWN 2)
 (def RIGHT 3)
-(def DIRECTIONS [UP RIGTH DOWN LEFT UP RIGHT])
+(def DIRECTIONS [UP RIGTH DOWN LEFT])
 
 
 (def WALL 0)
@@ -41,9 +41,13 @@
           '((succ x), y))))))
 
 (defn next [direction]
-  (nth DIRECTIONS (succ direction)))
+  (if (== direction LEFT)
+    UP
+    (let [pos (lookup DIRECTIONS direction)]
+      (nth DIRECTIONS (succ pos)))))
 
 (defn back [direction]
   (if (== direction UP)
     RIGHT
-    (nth DIRECTIONS (pred direction))))
+    (let [pos (lookup DIRECTIONS direction)]
+      (nth DIRECTIONS (pred pos)))))

strats/stdlib.clj

@@ -6,3 +6,10 @@
 
 (defn pred [x]
   (sub x 1))
+
+(defn lookup [list elem]
+  (let [lookup-in (fn [l p]
+                  (if (== (head l) elem)
+                    p
+                    (lookup-in (tail l) (succ p))))]
+    (lookup-in list 0)))