Elixir XML processing (to JSON) with SweetXML

elixir_xml.exs

# mix.exs file dependencies:
# defp deps do
#   [
#     {:sweet_xml, "~> 0.4.0"},
#     {:json, "~> 0.3.0"}
#   ]
# end

defmodule ElixirXml do
  import SweetXml

  def count_items(file) do
    File.stream!(file, [:read]) |> xpath(~x"//PatBase/Family/Patent"l) |> length
  end

  def elements(file) do
    # s-option forces to return strings instead of char lists
    File.stream!(file, [:read]) |> xpath(~x"//PatBase/Family/Patent"l, title: ~x"./Title/btitle/text()"s, pub_date: ~x"./PublicationDate/text()"s, pub_number: ~x"./PublicationNumber/text()"s )
  end

  def parse(file) do
    elements(file) |> to_json
  end

  defp to_json(attr_array) do
    JSON.encode(attr_array)
  end
end