Ruby：如何引用在模块外部定义的变量

Question

如何将processor_pool 传递给模块内的方法？

class Dummy

  def initialize
    processor_pool = Concurrent::FixedThreadPool.new(10)

    @threadpool = Module.new do
      extend Concurrent::Promises::FactoryMethods
      def self.default_executor
        return processor_pool  # this cannot find the processor_pool variable
      end
    end
  end

end

即使我将其设为@processor_pool 之类的实例变量，我也会遇到同样的错误

Answer 1

类似这样的东西（为了举例，我稍微简化了你的类以摆脱依赖关系，但它的结构是相同的）：

class Dummy
  attr_reader :threadpool
  
  def initialize
    processor_pool = "It works"

    @threadpool = Module.new do
      define_method :default_executor do
        return processor_pool
      end
      module_function :default_executor
    end
  end
end

Dummy.new.threadpool.default_executor # => "It works"