Simple FizzBuzz example using Elixir

fizzbuzz.exs

defmodule FizzBuzz do
  defguard is_fizz(value) when is_integer(value) and rem(value, 3) == 0
  defguard is_buzz(value) when is_integer(value) and rem(value, 5) == 0

  def run(val) do
    1..val
    |> Enum.each(fn val -> word(val) |> IO.inspect() end)
  end

  defp word(val) when is_fizz(val) and is_buzz(val), do: "fizzbuzz"
  defp word(val) when is_fizz(val), do: "fizz"
  defp word(val) when is_buzz(val), do: "buzz"
  defp word(val), do: val
end

FizzBuzz.run(20)