Question

我正在学习Ruby，并在Time遇到困难。以下是我需要传递的rspec要求：

it "takes about 1 second to run a block that sleeps for 1 second" do
  elapsed_time = measure do
    sleep 1
  end
  elapsed_time.should be_within(0.1).of(1)
end

measure的代码是：

def measure
  start = Time.now
  elapse = Time.now - start
end

我错过了什么？我无法通过睡眠1秒钟的块。我试着测试并调用块：

a = Proc.new{puts "hello"}
sleep 1
measure

# => Unknown error

Answer 1

您错过了在测量方法中调用yield：

def measure
  start = Time.now
  yield if block_given?
  elapse = Time.now - start
end

Answer 2

要了解Ruby的代码块，我建议你阅读this blog post。

正如您在此示例中所看到的那样：

def my_ordinary_method()
  #do stuff
  yield #the instruction that calls the block
  #do more stuff
end

def the_caller()
  #do stuff
  my_ordinary_method() do
    puts "I am the block. The one everyone talks about!"
    puts "I am gentle, colorful and polite"
  end
end

取自上面的链接。

您的代码应如下所示：

def measure
  start = Time.now
  yield if block_given?
  elapse = Time.now - start
end

休眠x秒的Ruby时间运行块

2 个答案: