Rust 相当于 try-catch 语句是什么? [英] What is the Rust equivalent to a try-catch statement?

问题描述

是否可以在 Rust 中一次处理多个不同的错误而不是单独处理而不使用附加功能?简而言之:什么是 Rust 等价于 try-catch 语句?

Is it possible to handle multiple different errors at once instead of individually in Rust without using additional functions? In short: what is the Rust equivalent to a try-catch statement?

这样的功能(使用 进行一流的错误处理? 和 catch) 早在 2016 年就被建议了，但我不知道结果如何以及 2019 年针对此类问题的解决方案会是什么样子.

A feature like this (First-class error handling with ? and catch) was suggested back in 2016, but I can't tell what came out of it and how a 2019 solution for such a problem might look like.

例如，做这样的事情:

try {
    do_step_1()?;
    do_step_2()?;
    do_step_3()?;
    // etc
} catch {
    alert_user("Failed to perform necessary steps");
}

代替:

match do_steps() {
    Ok(_) => (),
    _ => alert_user("Failed to perform necessary steps")
}

// Additional function:
fn do_steps() -> Result<(), Error>{
    do_step_1()?;
    do_step_2()?;
    do_step_3()?;
    // etc
    Ok(())
}

我的程序有一个函数，它检查注册表中不同位置的不同数据值并返回一些聚合数据.它需要在循环内的其他 try-catch 中使用许多这些 try-cache 语句和 try-catch.

My program has a function which checks a variety of different places in the registry for different data values and returns some aggregate data. It would need to use many of these try-cache statements with try-catch inside of other try-catch inside of loops.

推荐答案

Rust 中没有 try catch 语句.最接近的方法是 ? 运算符.

There is no try catch statement in Rust. The closest approach is the ? operator.

但是，您最终不必创建函数和match 语句来解决它.您可以在您的范围内定义一个闭包并在闭包内使用 ? 运算符.然后抛出被保存在闭包返回值中，你可以在任何你想要的地方捕捉它，如下所示:

However, you do not have to create a function and a match statement to resolve it in the end. You can define a closure in your scope and use ? operator inside the closure. Then throws are held in the closure return value and you can catch this wherever you want like following:

fn main() {
    let do_steps = || -> Result<(), MyError> {
        do_step_1()?;
        do_step_2()?;
        do_step_3()?;
        Ok(())
    };

    if let Err(_err) = do_steps() {
        println!("Failed to perform necessary steps");
    }
}

游乐场

是否可以在不使用其他函数的情况下一次处理多个不同的错误，而不是在 Rust 中单独处理?

Is it possible to handle multiple different errors at once instead of individually in Rust without using additional functions?

有一个 无论如何 板条箱用于现在主要推荐 Rust 中的错误管理.

There is a anyhow crate for the error management in Rust mostly recommended nowadays.

作为替代，有一个失败 用于 Rust 错误管理的箱子.使用 Failure，您可以链接、转换、连接错误.将错误类型转换为一种常见类型后，您可以轻松捕获(处理)它.

As an alternative, There is a failure crate for the error management in Rust. Using Failure, you can chain, convert, concatenate the errors. After converting the error types to one common type, you can catch (handle) it easily.

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