什么是Rust等同于try-catch语句？ [英] What is the Rust equivalent to a try-catch statement?

问题描述

是否可以一次处理多个不同的错误，而不是在Rust 中不使用其他功能而单独处理？简而言之：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?

这种功能（使用？和 catch ）是在2016年提出的，但我不知道从中得出什么，以及2019年针对此类问题的解决方案的样子。

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，执行以下操作：

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

而不是：

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(())
}

我的程序有一个功能，可以检查注册表中各种不同位置的不同数据值，并返回一些汇总数据。它将需要将许多try-cache语句与try-catch和其他try-catch一起使用在循环内部。

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，您不必创建函数和 match 语句最终解决它。您可以在范围内定义闭包，并在闭包内使用？运算符。然后，将引发保留在闭包的返回值中，您可以在任意位置捕获该错误，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

是否可以一次处理多个不同的错误，而不是在Rust中单独处理而无需使用其他功能？

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

是有可能的。 Rust中有一个 失败 板条箱用于错误管理。使用故障，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，您可以轻松地捕获（处理）它。

Yes it is possible. 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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