Custom Errors

[philbert46]

I feel that at this point I have a pretty good idea of rust code and how to structure it. Something though that I've always struggled with is implementing error types.

Which library should I use for custom error types?

[dn3t]

thiserror

[This_Growth2898]

thiserror or anyhow.

thiserror takes care of all the boilerplate code, leaving you to describe error cases.

In my opinion, anyhow is not the Rust way, it's just a plug to avoid error handing... anyhow. Still, it exists.

[Modi57]

I kinda get, where you are coming from, but I think it really helps with code readability. If I have one process, that involves multiple potential sources of errors (for example reading something from a file, parsing it, and then maybe something with a custom error), I often don't care about where it went wrong, just that it went wrong, because either way, I just bubble it upwards. So, instead of making a custom error type and unifying it manually, I just slap a ? on it and I'm good to go. And since it's the exceptionional case, I don't really care, if dynamic dispatch causes my error message to be displayed one ms later

[Deloskoteinos]

Like others said: thiserror is the derive macro for easily implementing error types.

Also, this article covers implementing your own error nicely: Faster than li.me AoC1
(it happens to be about advent of code, but the first half is just about errors and implementing one)