Elmchemy article #3

fizbuzz.ex

defmodule FizzBuzz do
  use Elmchemy

  import XList, only: [{:'range', 0},{:'map', 0}]
  @doc """
  Fizzes the buzzes and buzzfizzes the fizz out of buzz


      iex> import FizzBuzz
      iex> fizzbuzz.(1).(7)
      "1 2 Fizz 4 Buzz Fizz 7"


  """
  @spec fizzbuzz() :: (integer -> (integer -> String.t))
  @spec fizzbuzz(integer, integer) :: String.t
  curry fizzbuzz/2
  def fizzbuzz(from, to) do
    fizz_buzz = fn(n) -> case {rem(n, 3), rem(n, 5)} do
      {0, 0} -> "FizzBuzz"
      {0, _} -> "Fizz"
      {_, 0} -> "Buzz"
      _ -> to_string.(n)
    end end
    XList.range.(from).(to)
    |> (map.(fizz_buzz >>> to_string)).()
    |> (join_words).()
  end

  @spec join_words() :: (list(String.t) -> String.t)
  @spec join_words(list(String.t)) :: String.t
  defp join_words(list) do
    XString.join.(" ").(list)
  end

end