defmodule Gray do
  @moduledoc """
  This module helps you convert non_neq_integers to binary reflected gray code 
  and vice versa 
  """

  use Bitwise
  # import Gray.Utils, only: [to_binary: 1]

  @doc """
  Converts a non negative integer to its binary reflected gray code equivalent
  """
  def binary_to_gray(num) when is_integer(num) and num >= 0 do
    (num >>> 1) ^^^ num
  end

  @doc """
  Converts a binary reflected gray code number to its original decimal form
  """
  def gray_to_binary(num) when is_integer(num) and num >= 0 do
    gray_to_binary(num, num >>> 1)
  end

  # Recursive way to convert BRGC code to decimal form
  defp gray_to_binary(num, 0), do: num
  defp gray_to_binary(num, mask) do
    gray_to_binary(num ^^^ mask, mask >>> 1)
  end
end