This is me writing one hour of that episode of Pirandello and telling the other authors, here's what I'm assuming as you use it. So it's up to me to do it right, but if I do it, I'm going to specify, what does this function do?

作为一个程序员,我得为用户提供一些信息,这正是我写写的皮兰德娄戏剧的一小时片段,并且要告诉其它的作家，这是我希望你使用的地方，所以由我决定怎样去做好它？

麻省理工公开课 - 计算机科学及编程导论课程节选

So the exceptions are useful when you want to have the ability to say, I expect in general this kind of behavior, but I do know there are some other things that might happen and here's what I'd like to do in each one of those cases. But I do want to make sure that I don't let a value that I'm not expecting pass through.

所以当你希望有能力说,我希望一般是这样的行为,异常是很有用的,但是我明白还有一些其它的情况可能发生,我希望对每一种情况都这么做,但是我跟希望能保证,没有让一个预期之外的情况漏过去。

麻省理工公开课 - 计算机科学及编程导论课程节选