examples/higher.spl

   1 map(f, l){
   2         if(isEmpty(l)){
   3                 return [];
   4         } else {
   5                 return f(l.hd) : map(f, l.tl);
   6         }
   7 }
   8
   9 foldr(f, acc, l){
  10         if(isEmpty(l)){
  11                 return acc;
  12         } else {
  13                 return foldr(f, f(acc, l.hd), l.tl);
  14         }
  15 }
  16
  17 filter(f, l){
  18         if(isEmpty(l)){
  19                 return [];
  20         } else {
  21                 if(f(l.hd)){
  22                         return filter(f, l.tl);
  23                 } else {
  24                         return l.hd : filter(f, l.tl);
  25                 }
  26         }
  27 }
  28
  29 intList(x){
  30         if(x <= 1){
  31                 return [x];
  32         } else {
  33                 return x : intList(x-1);
  34         }
  35 }
  36
  37 giveF(){
  38     return (\x->x+1);
  39 }
  40
  41
  42
  43 main(){
  44     var x = 5;
  45
  46     var f = giveF();
  47
  48     var plus = \x y->x+y;
  49
  50     var g = map(plus, [1,2,3]);
  51     var is = map(\f->f(1), g);
  52
  53     //print("is.hd", is.hd);
  54
  55     print("f(4) = ", f(4));
  56
  57         print("faculty of 5 is: ", foldr(\x y->x*y, 1, intList(5)));
  58         print("sum of 1..5 is: ", foldr(\x y->x+y, 0, intList(5)));
  59         print("sum of 0..12 but only the evens: ",
  60                 foldr(\x y->x+y, 0, filter(\x->x%2 == 0, intList(12))));
  61 }