defp section_body(:function, chunk) do
    typeidx_vec(chunk)
  end
  defp typeidx_vec(chunk) do
    {length, rest} = u32(chunk)
    do_typeidx_vec(length, rest)

  defp do_typeidx_vec(length, chunk) do
    do_typeidx_vec(length, chunk, [])

  defp do_typeidx_vec(0, chunk, acc) do
    {acc |> Enum.reverse(), chunk}
  end
  defp do_typeidx_vec(length, chunk, acc) do
    {index, rest} = u32(chunk)
    do_typeidx_vec(length - 1, rest, [index | acc])
  end