should have document on best practice about how to `throw custom error` #1405

loynoir · 2023-09-23T15:42:17Z

Seperated document issue from previous

From my newbee understanding

typescript throw error equivalent

    throw new Error("msg");

should be

    panic!("msg");

But typescript throw custom error equivalent seems very complicated.

class OddEvenError extends Error { }

function castOdd(): Odd {
    throw new OddEvenError('not odd')
}

    struct Odd(u32);

    #[derive(Debug)]
    struct OddEvenError {
        message: String,
    }

    impl OddEvenError {
        fn new(message: &str) -> Self {
            OddEvenError {
                message: message.to_string(),
            }
        }
    }

    impl Error for OddEvenError {}

    impl std::fmt::Display for OddEvenError {
        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
            write!(f, "{}", self.message)
        }
    }

    fn cast_odd() -> Result<Odd, Box<dyn Error>> {
        Err(Box::new(OddEvenError::new("not odd")))
    }

    cast_odd().expect("err");

The text was updated successfully, but these errors were encountered:

bjorn3 · 2023-09-23T19:09:31Z

The reference describes the rust language itself, not what idiomatic rust is, nor how to learn it as beginner. The rust book is meant for learning rust. In this specific case Chapter 9: Error Handling is relevant.

ehuss · 2023-09-25T16:55:59Z

As mentioned, the reference isn't intended for new learners, or for how to map concepts from another language to Rust. If you are having questions on how to do things, I suggest trying one of the user forums such as https://users.rust-lang.org/.

loynoir · 2023-09-25T18:50:51Z

Ah, sorry.

I mis-understood as this repo is for rust document team.

loynoir changed the title ~~should have document best practice on how to throw custom error~~ should have document on best practice about how to throw custom error Sep 23, 2023

ehuss closed this as not planned Won't fix, can't repro, duplicate, stale Sep 25, 2023

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should have document on best practice about how to `throw custom error` #1405

should have document on best practice about how to `throw custom error` #1405

loynoir commented Sep 23, 2023

bjorn3 commented Sep 23, 2023

ehuss commented Sep 25, 2023

loynoir commented Sep 25, 2023

should have document on best practice about how to throw custom error #1405

should have document on best practice about how to throw custom error #1405

Comments

loynoir commented Sep 23, 2023

bjorn3 commented Sep 23, 2023

ehuss commented Sep 25, 2023

loynoir commented Sep 25, 2023

should have document on best practice about how to `throw custom error` #1405

should have document on best practice about how to `throw custom error` #1405