functional-oop-mixins.js

function fly(creature) {
  return (
    "The " + creature.species +
    " flies using its " + creature.methodOfFlight
  );
}

function hunt(creature, otherCreature) {
  return (
    "The " + creature.species +
    " hunts the " + otherCreature.species +
    " using its " + creature.methodOfHunting
  );
}

function CreateCreature(species) {
  return {species};
}

function CreatePredator(species, methodOfHunting) {
  const creature = {species, methodOfHunting};
  creature.hunt = hunt.bind(null, creature);
  return creature;
}


function CreateFlyingPredator(species, methodOfFlight, methodOfHunting) {
  const creature = {species, methodOfFlight, methodOfHunting};
  creature.fly = fly.bind(null, creature);
  creature.hunt = hunt.bind(null, creature);
  return creature;
}

const rabbit = CreatePredator("rabbit");
const wolf = CreatePredator("wolf", "teeth");
const eagle = CreateFlyingPredator("eagle", "wings", "talons");

console.log(rabbit);
console.log(eagle);
console.log(wolf);
console.log(wolf.hunt(rabbit));
console.log(eagle.hunt(wolf));
console.log(eagle.fly());