ElixirのマクロでFizzBuzz

fizzbuzz_macro.exs

defmodule FizzBuzzDefine do
  def define_taple do
    [{"fizz", 3}, {"Buzz", 5}]
  end
end


defmodule FizzBuzzHelper do
  import FizzBuzzDefine

  defmacro mod_zero_string do
    for {name, x} <- define_taple do
      quote do
        def unquote(:"#{name}")(x) do
          if rem(x, unquote(x)) == 0 do
            unquote(name)
          else
            ""
          end
        end
      end
    end
  end

  defmacro define_to_s do
    functions = Enum.map(define_taple, &(elem(&1, 0)))
    quote do
      def to_s(i) do
        function_strings = Enum.map_join(unquote(functions), &(apply(FizzBuzz, :"#{&1}", [i])))
        if function_strings == "", do: to_string(i), else: function_strings
      end
    end
  end
end

defmodule FizzBuzz do
  import FizzBuzzHelper

  mod_zero_string
  define_to_s

  def forprint(x) do
    for i <- 1..x do
      IO.puts to_s(i)
    end
  end
end

FizzBuzz.forprint(100)