macro_helpers.ex

defmodule MacroHelpers do
  @doc """
  Converts block AST to a list
  You could pass function names which results should be included to the list
  
  Examples:
  
      block_to_list(ast, [:column])
  """
  def block_to_list(block, search_for \\ []) do
    search_for = MapSet.new(search_for)
    case block do
      {:__block__, trace, ast} ->
        {:__block__, trace, handle_block_ast(ast, search_for)}
      _ ->
        [block]
    end
  end

  defp handle_block_ast(list, search_for \\ %MapSet{}, acc \\ [])
  defp handle_block_ast([], %MapSet{}, acc) do
    [{:=, [], [{:buffer, [], __MODULE__}, []]} | acc]
  end
  defp handle_block_ast([line|tail], [], acc) do
    new_line = case line do
      {:=, _, _} ->
        line
      _ ->
        {:=, [], [{:buffer, [], __MODULE__}, [{:|, [], [line, {:buffer, [], __MODULE__}]}]]}
    end
    handle_block_ast(tail, %MapSet{}, [new_line | acc])
  end
  defp handle_block_ast([line|tail], search_for, acc) do
    {function, _, _} = line
    new_line = if MapSet.member?(search_for, function) do
      {:=, [], [{:buffer, [], __MODULE__}, [{:|, [], [line, {:buffer, [], __MODULE__}]}]]}
    else
      line
    end
    handle_block_ast(tail, search_for, [new_line | acc])
  end
end