parallel.ex

#---
# Excerpted from "Programming Elixir",
# published by The Pragmatic Bookshelf.
# Copyrights apply to this code. It may not be used to create training material, 
# courses, books, articles, and the like. Contact us if you are in doubt.
# We make no guarantees that this code is fit for any purpose.  # Visit http://www.pragmaticprogrammer.com/titles/elixir for more book information.
#---
defmodule Parallel do
  def pmap(collection, fun) do
    me = self

    collection
    |>
    Enum.map(fn (elem) ->
      spawn_link fn -> (send me, { self, fun.(elem) }) end
    end)
    |> 
    Enum.map(fn (pid) ->
      receive do { ^pid, result } -> result end
    end)
  end
end

parallel_test.ex

defmodule ParallelTest do
  use ExUnit.Case

  test "the truth" do
    assert(true)
  end

  test "i can do math" do
    result = Parallel.pmap 1..100000000, &(&1 * &1)
    assert true
  end
end