Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

My Struggles with Rust

compileandrun.com

Post reply on HN
Print view View original

11–20 of 329 posts

Re: My Struggles with Rust

#11

Post by Inufu »

pornel wrote: post #6
Inufu wrote: post #4

My main gripe with Rust so far has been the unnecessary profusion of Result types, making it hard to process and forward errors. Case in point: the example in the article from the rust documentation that converts errors to strings just to forward them: https://doc.rust-lang.org/book/error-handling.html#the-limit... In practice, I find a type like Google's util::StatusOr ( https://github.com/google/lmctfy/blob/master/…

With the addition of `?` operator I think it's no longer the problem. It keeps error handling explicit, but the syntax is small enough that it doesn't make code noisy or tedious to write. Note that you can also make your functions return `Box ` which works like a base class for all common errors, so you don't have to worry about converting error types.

Sure, but if you want to actually check for some error condition (say distinguish between file opened ok, file not found, or some other error) - which is the whole point of having an error type to begin with, otherwise you could just use optional - you still have to look up the definition of the actual error type used every time.

A standardized error type used by everything removes that need - I know I can just call util::IsNotFoundError(..), no matter which library I'm using.

Re: My Struggles with Rust

#14

Post by doubleplusgood »

dep_b wrote: post #7

The big question is would the Python script crash or handle the error when obvious problems like not valid JSON or file not found happen? My experience with Swift vs Objective-C is that clean Swift is crash free but more verbose when all other things are equal. If you don't need that level of security because it's just a small script Python was the right choice.

It would just raise an OSError/IOError/TypeError/ValueError and exit (unless caught).

Re: My Struggles with Rust

#15

Post by JoshTriplett »

thegeomaster wrote: post #10

The `error-chain` crate [1] exists to get rid of precisely the error handling boilerplate the author has encountered. That's not ideal, though, as I believe that a place for such functionality is in the core language, not a separate library, but it gets the job done. As for the `let mut file` bit, that makes sense to me: a file in the standard library is an abstraction over a file descriptor in the operating system,…

I'd like to see error-chain standardized into the standard library as well. It seems by far the most sensible approach to building Error types.

Re: My Struggles with Rust

#16

Post by Veedrac »

amelius wrote: post #8
pornel wrote: post #2

These struggles are real. I don't see a way around them other than just learning them (and then they go away, because you know what code won't work, and don't fight it). It's probably because Rust looks and operates mostly like a high-level language, but still satisfies low-level constraints. e.g. the confusing difference between `&str` and `String` is equivalent of C's `const char * str = ""` vs `char * String = mal…

> It's probably because Rust looks and operates mostly like a high-level language, but still satisfies low-level constraints. In an ideal language, you could decide to ignore low-level constraints and your code would work just fine, although perhaps less efficiently.

Rust is targeting an audience where silently degrading performance is problematic.

Re: My Struggles with Rust

#17

Post by Symmetry »

vfclists wrote: post #12

Use Nim

The author was using this as an opportunity to learn Rust so while it might look sort of crazy to use a systems programming language for build failure notification there was a reason behind their decision. Nim is a lovely language but in the author's case he doesn't really care about speed for the use case so if they were being strictly pragmatic they could have just stuck with Python.

Re: My Struggles with Rust

#18

Post by jimktrains2 »

cousin_it wrote: post #13

Rust's aversion to exceptions is exactly like Go's aversion to generics - a strongly held position that doesn't actually make anyone's life easier.

I find result types to be much easier to understand and work with than exceptions. Result types can be handled by the type system, even when you have checked exceptions in java, there are still exceptions that aren't checked, and the syntax for the checking becomes monstrous.

Re: My Struggles with Rust

#19

Post by hasenj »

dep_b wrote: post #7

The big question is would the Python script crash or handle the error when obvious problems like not valid JSON or file not found happen? My experience with Swift vs Objective-C is that clean Swift is crash free but more verbose when all other things are equal. If you don't need that level of security because it's just a small script Python was the right choice.

It would crash but would print an error message along with a stack trace. The rust version will probably just crash with a confusing error.

Re: My Struggles with Rust

#20

Post by kancer »

Inufu wrote: post #4

My main gripe with Rust so far has been the unnecessary profusion of Result types, making it hard to process and forward errors. Case in point: the example in the article from the rust documentation that converts errors to strings just to forward them: https://doc.rust-lang.org/book/error-handling.html#the-limit... In practice, I find a type like Google's util::StatusOr ( https://github.com/google/lmctfy/blob/master/…

You may be interested in something like https://github.com/tailhook/quick-error. It lets you easily implement From traits for errors so that you can convert between error types.
Post reply on HN