That's why you have wrappers that return Result enumerations. There is an overhead to check if an operation is valid, pay for it if you need it.
This is exactly how Rust works, for example.
This is exactly how Rust works, for example.
As a C# and Typescript developer primarily, this concept of killing the whole program due to a bug anywhere in any part of the code is very foreign to me.
I’d expect that to only happen if you ran out of memory, had a hardware failure, or other such catastrophic error. To me, dividing by zero is a problem, but not worse than pretty much any other type of logical error that doesn’t panic.
But getting the wrong answer due to a bug anywhere in any part of the code is not?
Why single out just a few types of bugs to crash the whole program? Let me catch it and decide what to do.
If it’s in a single request to my web server, I’d like that single request return an error code. I would not like all other concurrent requests for all other users to fail as well.
Complaints range from too slow to hidden control flow to just not liking them.
I absolutely see the benefit in application code, otherwise you're error checking every function call.
On the other hand, I completely understand not using such a mechanism in kernel and driver code.
But Rust has decided against exceptions (which I actually believe were part of the original vision way back when, but please don't quote me), so now there's panics.
Everything is a tradeoff at some level.
Overall, I'm not entirely sure if Rust would be better or not if panics were non-recoverable.
PS: For completeness, there are flags to control the panic behavior; but you can't rely on them when writing a lib.
> It is not recommended to use this function for a general try/catch mechanism. The Result type is more appropriate to use for functions that can fail on a regular basis. Additionally, this function is not guaranteed to catch all panics, see the “Notes” section below.
I think panics in Rust are intended to be unrecoverable, and catch_unwind is mainly intended to make the shutdown more orderly and possibly localized. Any data structure that paniced is probably in an unknown state that is not safe for further use.
https://github.com/tokio-rs/tokio/issues/2002#issuecomment-6...
And web frameworks like Tower provide standard ways of handling panics and turning them into error responses.
https://docs.rs/tower-http/latest/tower_http/catch_panic/ind...
So I don’t think panics are necessarily meant to be program-killing in Rust, even if Result types are heavily recommended instead.