elixir - 通过委托(delegate)现有功能实现协议(protocol)

Question

我正在通过对棋盘游戏建模来学习 Elixir，并且我有以下代码:

defprotocol Board do
  def can_handle_move(self)
  def handle_move(self, move)
end

defimpl Board, for: List do
  def can_handle_move(self), do: Enum.empty?(self)
  def handle_move(self, move), do: List.delete(self, move)
end

实现看起来比实际更复杂。实际上， can_handle_move只是 Enum.empty?和 handle_move只是 List.delete . Elixir 有办法表达这一点吗？就像是:

defimpl Board, for: List do
  def can_handle_move = &Enum.empty?/1
  def handle_move = &List.delete/2
end

...无法编译。我也试过没有 def s。

Answer 1

试试 Kernel#defdelegate/2为了它。

defimpl Board, for: List do
  defdelegate can_handle_move(self), to: Enum, as: :empty?
  defdelegate handle_move(self, move), to: List, as: :delete
end