class_warpper.cr

class_warpper.cr

lib LibPet
  alias Pet = Void*
  alias Dog = Void*

  fun make_dog : Dog
  fun bark(bar : Dog)
  fun move(pet : Pet)
  fun retreat(pet : Pet)
  fun sell(pet : Pet)
end

alias Dog = lib::Dog
struct Dog
  def self.new
    LibPet.make_dog
  end

  def bark
    LibPet.bark(self)
  end

  def move
    LibPet.move(self)
  end

  def retreat
    LibPet.retreat(self)
  end
# or macro:
#   def_delgators LibPet, :bark, :move, :retreat

  def at_front
    move
    yield
  ensure
    retreat
  end

  def attack
    at_front { bark }
  end
end

# So That:
def sell_dog(dog : Dog)
    LibPet.sell_pet dog
# rather than
#   LibPet.sell_pet dog.dog
#   `dog.dog` is too silly, don't it?
end