4.1 Polymorphic Objects

Named object factories can be polymorphic because they're just functions, and functions can be polymorphic:

  object fred[T] (x:list[T]) = 
  {
    method proc print () { println$ x; }
    method fun get () => x;
  }
  
  var lst = list$ 1,2,3;
  var a = fred lst;
  
  a.print();
  println$ a.get();

Naturally interfaces can also be polymorphic because records can:

  interface A[T] { print : 1 -> 0; get: 1 -> list[T]; }
  object joe[T] (x:list[T]) implements A[T] = 
  {
    method proc print () { println$ x; }
    method fun get () => x;
  }