Ruby时间运行块，休眠x秒

Question

我正在学习Ruby，并经历了Time的艰难时期。以下是我需要通过的rspec的要求:

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

我的measure代码是:

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

我错过了什么?我不能通过只睡1秒的块。我试着测试并调用block:

a = Proc.new{puts "hello"}
sleep 1
measure
# => Unknown error

Answer 1

您错过了在度量方法中调用yield:

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

Answer 2

要理解Ruby的代码块，我建议你阅读这篇博文。

你可以从这个例子中看到:

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

摘自上面的链接。

你的代码应该是这样的:

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