Comment by LoganDark
18 hours ago
thiserror and anyhow are just std::error with extra steps. Note that io::error is just a specific std::error.
The entire point in Rust is that you wrap Error impls with other Error impls, or translate one impl into another using a match. I've found this is far more flexible and verifiable than most other languages, because if you craft your error types with enough rigor, you can basically have a complete semantic backtrace without the overhead of a real backtrace.
I use thiserror a lot to help with my impls. Notably, all it does is impl Display and Error. It's not a specific other paradigm because it basically compiles out, it's just a macro.
Anyhow is perhaps the closest one to another paradigm because it allows you to discard typed information in favor of just the string messages, but it still integrates well with Errors (and is one).
thiserror and anyhow are std::error::Error with fewer steps.
They're external crates that either generate Error implementations (thiserror) or act as dynamic wrappers implementing Error (anyhow), so they're more than a simple hand-written implementation. But the developer experience of pulling thiserror or anyhow off the shelf can certainly be more convenient than the hand-written implementation, sure.