demos/objects/objects-wiki.c

   1 #include "cll1.h"
   2
   3 /* This is C<<1 rewrite of object polymorphism from
   4    http://en.wikipedia.org/wiki/Polymorphism_in_object-oriented_programming */
   5
   6 def_type(Animal);
   7
   8 def_mem(Actions)
   9 {
  10  Animal method(init) (Animal self, str name);
  11  str method(talk) (Animal self);
  12 };
  13
  14 def_obj(Animal)
  15 {
  16  interface(Actions);
  17  char *name;
  18 };
  19
  20 str cat_talk(Animal self)
  21 {
  22  return "Meow!";
  23 }
  24
  25 str dog_talk(Animal self)
  26 {
  27  return "Arf! Arf!";
  28 }
  29
  30 Animal animal_init(Animal self, str name)
  31 {
  32  self->name = name;
  33  return self;
  34 }
  35
  36 Actions cat_actions(Actions this)
  37 {
  38  this->init = animal_init;
  39  this->talk = cat_talk;
  40 }
  41
  42 Actions dog_actions(Actions this)
  43 {
  44  this->init = animal_init;
  45  this->talk = dog_talk;
  46 }
  47
  48 program
  49 {
  50  int i;
  51  Animal animal[3];
  52  Actions cat = cat_actions();
  53  Actions dog = dog_actions();
  54
  55  animal[0] = init_obj(Animal, Actions, cat)
  56   "Missy");
  57  animal[1] = init_obj(Animal, cat, "Mr. Bojangles");
  58  animal[2] = init_obj(Animal, dog, "Lassie");
  59
  60  for_range(i, 0, 2)
  61  {
  62   printf("%s: %s\n", animal[i].name, _(talk, animal[i]));
  63  }
  64 }