Rule 30 using Elixir streams

rule30.exs

# https://en.wikipedia.org/wiki/Rule_30

defmodule Rule30 do
  def stream(values) do
    Stream.resource(fn -> {values, 0} end, &next_fun/1, fn _ -> :ok end)
  end

  defp next_fun({values, layer}) do
    next = ([0, 0] ++ values ++ [0, 0])
    |> Enum.chunk_every(3, 1, :discard)
    |> Enum.map(&rule/1)
    {values |> Enum.map(&{layer, &1}), {next, layer + 1}}
  end

  defp rule([1, 1, 1]), do: 0
  defp rule([1, 1, 0]), do: 0
  defp rule([1, 0, 1]), do: 0
  defp rule([1, 0, 0]), do: 1
  defp rule([0, 1, 1]), do: 1
  defp rule([0, 1, 0]), do: 1
  defp rule([0, 0, 1]), do: 1
  defp rule([0, 0, 0]), do: 0
end

Rule30.stream([1])
|> Enum.take(9)
|> IO.inspect