REPL

defp do_eval(model, code) do
  case Evaluator.eval(model.evaluator, code,
         timeout: @eval_timeout,
         max_heap_bytes: @eval_max_heap_bytes,
         max_result_bytes: @eval_max_output_bytes
       ) do
    {:ok, result, new_eval} ->
      output_lines = format_result(result)
      new_history = [code | model.input_history] |> Enum.take(@max_history)

      model
      |> Map.put(:evaluator, new_eval)
      |> Map.put(:input, "")
      |> Map.put(:cursor, 0)
      |> Map.put(:history_index, nil)
      |> Map.put(:input_history, new_history)
      |> add_output_lines([{"> #{code}", :input} | output_lines])

    {:error, reason, _eval} ->
      append_output(model, code, reason, :error)
  end
end