examples/peano.spl

   1 hyper(n, a, b){
   2         if(n == 0){                                     return b + 1;
   3         } else { if(b == 0 && n == 1){  return a;
   4         } else { if(b == 0 && n == 2){  return 0;
   5         } else { if(b == 0 && n >= 3){  return 1;
   6         } else {                                                return hyper(n-1, a, hyper(n, a, b - 1));
   7         }}}}
   8 }
   9
  10 main(){
  11         var plus = hyper(2);
  12         var times = hyper(3);
  13         var power = hyper(4);
  14         var arrow = hyper(5);
  15
  16         print("2 + 4 = ", plus(2, 4));
  17         print("2 * 4 = ", times(2, 4));
  18         print("2 ^ 4 = ", power(2, 4));
  19         print("3 | 2 = ", arrow(3, 2));
  20 }