クリスマスプレゼント交換会にElixirで備える

secret_santa.ex

defmodule SecretSanta do
  def static_solver, do: static_member() |> _solver()
  def random_solver, do: random_member() |> _solver()
  defp _solver(lst) do
    lst |> Enum.shuffle() |> print_result()
  end

  defp static_member, do: ["tomoya", "nagisa", "kyou",  "ryou", "tomoyo", "kotomi"]
  defp random_member, do: Enum.map(1..100, fn n -> "mr_#{n}" end)
  defp template_print(from, to), do: IO.puts("#{from} => #{to}")
  defp print_result([h | _] = lst), do: _print_result(lst, h)
  defp _print_result([], _), do: :ok
  defp _print_result([h | []], first) do
    template_print(h, first)
    _print_result([], first)
  end
  defp _print_result([h | t], first) do
    next = Enum.at(t, 0)
    template_print(h, next)
    _print_result(t, first)
  end
end

SecretSanta.random_solver()
SecretSanta.static_solver()