min_delegate

Helps you to easily define call and cast, info functions when using gen_server for elixir

Overview

If you often use GenServer, define and implement the function as shown in the following example.

defmodule SimpleServer do
  use GenServer

  ### GenServer Initializations
  def init(_state), do: {:ok, []}
  def start_link(state \\ []) do
    GenServer.start_link(__MODULE__, state, name: __MODULE__)
  end

  ### APIs for caller
  def add_value(value), do: GenServer.call(__MODULE__, {:add_value, value})

  @doc """
  GenServer.handle_call/3 callback
  """
  def handle_call({:add_value, value}, _from, state), do: {:reply, value, [value | state]}

end

If you use min_delegate

• It can reduce the functions that always define in two pair to one.
• It increases readibility in a way.
• It can reduce the possibility of errors.

defmodule MinDelegateQ do
  use GenServer
  use MinDelegate

  def init(_state), do: {:ok, []}

  def start_link(state \\ []) do
    GenServer.start_link(__MODULE__, state, name: __MODULE__)
  end

  @alias :data
  defcall add_value(value, data) do
    data = [value | data]
    {:reply, data, data}
  end

  defcast add_value_cast(value, state) do
    {:noreply, [value | state]}
  end

  defcall count(state) do
    {:reply, length(state), state}
  end

  definfo add_value_info(value, state) do
    { :noreply, [value | state] }
  end
end

defmodule MinDelegateTest do
  use ExUnit.Case

  test "min_delegate" do
    {:ok, pid} = GenServer.start_link(MinDelegateQ, [], [])
    ret = MinDelegateQ.add_value(pid, 4)
    assert(ret == [4])
    ret = MinDelegateQ.add_value(pid, 1)
    assert(ret == [1, 4])
    MinDelegateQ.add_value_cast(pid, 2)
    ret = MinDelegateQ.add_value(pid, 3)
    assert(ret == [3, 2, 1, 4])
    MinDelegateQ.add_value_info(pid, 7)
    ret = MinDelegateQ.add_value(pid, 8)
    assert(ret == [8, 7, 3, 2, 1, 4])
    assert(MinDelegateQ.count(pid) == 6)
  end
end

In summary, when you use gen_server, can define and use it quickly.

Installation

If available in Hex, the package can be installed by adding min_delegate to your list of dependencies in mix.exs:

def deps do
  [
    {:min_delegate, "~> 0.1.0"}
  ]
end

Usage