Go语言的创造者写道:

Go doesn't provide assertions. They are undeniably convenient, but our experience has been that programmers use them as a crutch to avoid thinking about proper error handling and reporting. Proper error handling means that servers continue operation after non-fatal errors instead of crashing. Proper error reporting means that errors are direct and to the point, saving the programmer from interpreting a large crash trace. Precise errors are particularly important when the programmer seeing the errors is not familiar with the code.

你对此有什么看法?


当前回答

简短的回答:不,我相信断言可能有用

其他回答

作为附加信息,go提供了一个内置函数panic。这可以用来代替assert。如。

if x < 0 {
    panic("x is less than 0");
}

Panic将打印堆栈跟踪,因此在某种程度上它具有assert的目的。

与其说是坏事,不如说是适得其反。永久性错误检查和调试是分开的。Assert让人们认为所有的调试都应该是永久性的,使用过多会导致大量的可读性问题。在需要时,永久错误处理应该比这种方法更好,由于assert会导致自己的错误,因此这是一种非常值得怀疑的实践。

我更倾向于避免在调试和发布中做不同事情的代码。

但是,在一个条件下中断调试器并获得所有文件/行信息,以及确切的表达式和确切的值是有用的。

拥有一个“只在调试中评估条件”的断言可能是一种性能优化,因此,它只在0.0001%的程序中有用——人们知道他们在做什么。在所有其他情况下,这是有害的,因为表达式实际上可能改变程序的状态:

assert(2 == shroedingerscat . getnummears ()); 会使程序在调试和发布时做不同的事情。

我们开发了一组assert宏,可以在调试版和发布版中抛出异常。例如,THROW_UNLESS_EQ(a, 20);what()消息同时包含文件、行和a的实际值,等等,将抛出异常。只有宏才有这个功能。调试器可以配置为在特定异常类型的'throw'时中断。

我承认使用了断言,但没有考虑适当的错误报告。然而,这并不意味着它们在正确使用时是非常有用的。

They are especially useful for if you want to follow the "Crash Early" principle. For example suppose you're implementing a reference counting mechanism. At certain locations in your code you know that the refcount should be zero or one. And also suppose that if the refcount is wrong the program won't crash immediately but during the next message loop at which point it will be difficult to find out why things went wrong. An assert would have been helpful in detecting the error closer to its origin.

我从不使用assert(),示例通常是这样的:

int* ptr = new int[10];
assert(ptr);

这很糟糕,我从来没有这样做过,如果我的游戏分配了一堆怪物怎么办?为什么我要让游戏崩溃,相反,你应该优雅地处理错误,所以可以这样做:

CMonster* ptrMonsters = new CMonster[10];
if(ptrMonsters == NULL) // or u could just write if(!ptrMonsters)
{
    // we failed allocating monsters. log the error e.g. "Failed spawning 10 monsters".
}
else
{
    // initialize monsters.
}