View difference between Paste ID: FG4ZLDtA and ZS3iB0iH

 rev(Node xs):
    index = nil;
-   index = nil
+
    while (xs != nil)
-	index = xs.next();
+	index = xs;
-   	xs.next = xs;
+	result = xs.next();
-   	xs = index
+   	xs.next = index;
    	xs = result;