Elixir FizzBuzz server

fizzbuzz.ex

defmodule FizzBuzz do
  def compute do
    receive do
      n -> IO.puts compute(n)
    end
    compute
  end

  defp compute(n) do
    case {rem(n, 3), rem(n, 5)} do
      {0, 0} -> :FizzBuzz
      {0, _} -> :Fizz
      {_, 0} -> :Buzz
      _      -> n
    end
  end
end

# Usage example:
# fb = spawn FizzBuzz, :compute, []
# for x <- 1..15, do: send(fb, x)
# Enum.map(1..15, &send(fb, &1))

fizzbuzz_otp.ex

defmodule FizzBuzz do
  use GenServer

  ## Client API

  def start(opts \\ []), do: GenServer.start_link(__MODULE__, :ok, opts)
  def compute(server, n), do: GenServer.call(server, {:print, n})

  ## Server Callbacks

  def init(:ok) do
    IO.puts "FizzBuzz server started"
    {:ok, %{}}
  end

  def handle_call({:print, n}, _from, state) do
    if Dict.has_key?(state, n) do
      IO.puts "Fetching #{n}"
      {:ok, s} = Dict.fetch(state, n)
    else
      IO.puts "Calculating #{n}"
      s = case {rem(n, 3), rem(n, 5)} do
        {0, 0} -> :FizzBuzz
        {0, _} -> :Fizz
        {_, 0} -> :Buzz
        _      -> n
      end
    end
    IO.puts s
    {:reply, s, Dict.put(state, n, s)}
  end
end

# Usage example
# {:ok, fb} = FizzBuzz.start
# 1..15 |> Enum.map(&FizzBuzz.compute(fb, &1))