fizzbuzz.exs

defmodule Fizzy do
  def fizzbuzz(n) when rem(n, 5) == 0 and rem(n, 3) == 0, do: "FizzBuzz"
  def fizzbuzz(n) when rem(n, 3) == 0, do: "Fizz"
  def fizzbuzz(n) when rem(n, 5) == 0, do: "Buzz"
  def fizzbuzz(n), do: n

  def run(range) do
    range
    |> Enum.map(&fizzbuzz/1)
    |> Enum.map(&IO.puts/1)
  end
end

defmodule Buzzy do
  def fizzbuzz(n), do: _fizzbuzz(n, rem(n, 3), rem(n, 5))
  defp _fizzbuzz(_, 0, 0), do: "FizzBuzz"
  defp _fizzbuzz(_, 0, _), do: "Fizz"
  defp _fizzbuzz(_, _, 0), do: "Buzz"
  defp _fizzbuzz(n, _, _), do: n

  def run(range) do
    range
    |> Enum.map(&fizzbuzz/1)
    |> Enum.map(&IO.puts/1)
  end
end

Fizzy.run(1..16)
IO.puts("----")
Buzzy.run(1..16)