challenge1.exs

# Challenge 1: Given a list of integers, create a module that maps that list
# into different processes. Deliver to those processes the element and a
# function to be performed with it. This function can be anything, for
# instance: "Returns square of the number". Finally each process shoud send
# a message to the spawning process with the result.

defmodule Spawner do
  @moduledoc """
  Maps a list into processes performing a given function. Each one sends a
  message to the spawning process, this one uses the IO module to print it out.

  ## Examples

      iex> Spawner.map([1, 2, 3], fn(x) -> x * 2 end)
      2
      4
      6

  """
  @spawner self

  def map(list, func) do
    list
    |> Enum.map(fn element -> spawn(fn ->
      send(@spawner, {self, func.(element)})
    end) end)
    |> Enum.map(fn pid ->
      receive do
        {^pid, result} -> IO.puts result
      end
    end)
  end
end