refactored.ex

defmodule PuzzledPintScriptElixir do
  @base_string "http://www.puzzledpint.com/puzzles/august-2015/semaphore/"

  defp get_file_strings do
    File.read! "/usr/share/dict/cracklib-small"
  end

  def list_of_urls do
    get_file_strings
    |> String.split("\n", trim: true)
    |> Enum.filter(fn line -> String.length(line) == 7 end)
    |> Enum.map(fn line -> @base_string <> line end)
  end

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

  def main do
    list_of_urls
    |> Stream.map(&IO.inspect/1)
    |> pmap_printer_func(&HTTPotion.get/1)
    |> Enum.map(&log_errors/1)
  end

  @doc """
  Prints the urls if the response was 404
  """
  def log_errors({%{status_code: 404}, url} = result) do
    IO.puts url
    result
  end
  def log_errors(result), do: result
end