simple_dsl_example.rb

class Survey
  def initialize(title, &block)
    @title = title
    instance_eval(&block)
  end

  def question(question_title, &block)
    questions << Question.new(question_title, &block)
  end

  def questions
    @questions ||= []
  end

  def run
    puts @title
    questions.each(&:run)
  end
end

class Question
  def initialize(title, &block)
    @title = title
    instance_eval(&block)
  end

  def answer(answer_text)
    answers << answer_text
  end

  def answers
    @answers ||= []
  end

  def run
    puts @title
    answers.each_with_index do |answer, index|
      puts "#{index + 1}. #{answer}"
    end
    result_number = gets.chomp.to_i - 1
    result = answers[result_number]
    puts "Your answer is #{result}"
  end
end

def survey(title, &block)
  Survey.new(title, &block).run
end

survey 'Survey title' do
  question 'Question 1 title' do
    answer 'Option 1'
    answer "Option 2"
  end

  question 'Question 2 title' do
    answer 'Option 3'
    answer 'Option 4'
  end
end