←back to thread

611 points LorenDB | 1 comments | | HN request time: 0.233s | source
Show context
dvratil ◴[] No.43908097[source]
The one thing that sold me on Rust (going from C++) was that there is a single way errors are propagated: the Result type. No need to bother with exceptions, functions returning bool, functions returning 0 on success, functions returning 0 on error, functions returning -1 on error, functions returning negative errno on error, functions taking optional pointer to bool to indicate error (optionally), functions taking reference to std::error_code to set an error (and having an overload with the same name that throws an exception on error if you forget to pass the std::error_code)...I understand there's 30 years of history, but it still is annoying, that even the standard library is not consistent (or striving for consistency).

Then you top it on with `?` shortcut and the functional interface of Result and suddenly error handling becomes fun and easy to deal with, rather than just "return false" with a "TODO: figure out error handling".

replies(24): >>43908133 #>>43908158 #>>43908212 #>>43908219 #>>43908294 #>>43908381 #>>43908419 #>>43908540 #>>43908623 #>>43908682 #>>43908981 #>>43909007 #>>43909117 #>>43909521 #>>43910388 #>>43912855 #>>43912904 #>>43913484 #>>43913794 #>>43914062 #>>43914514 #>>43917029 #>>43922951 #>>43924618 #
dabinat ◴[] No.43908419[source]
I wish Option and Result weren’t exclusive. Sometimes a method can return an error, no result or a valid result. Some crates return an error for “no result”, which feels wrong to me. My solution is to wrap Result<Option>, but it still feels clunky.

I could of course create my own type for this, but then it won’t work with the ? operator.

replies(6): >>43908475 #>>43908590 #>>43908603 #>>43909135 #>>43916870 #>>43928540 #
1. Arnavion ◴[] No.43909135[source]
Result<Option> is the correct way to represent this, and if you need further convincing, libstd uses it for the same reason: https://doc.rust-lang.org/stable/std/primitive.slice.html?se...