Crumb

hades

u/hades@programming.dev
22 posts · 63 comments

Recent posts

Recent comments

on Feedback for first Rust Program · c/rust · 1 pts · 140d

Rust Error Handling and Rust in General is still a big black box for me yet to be unveiled :D

Conceptually, error handling in Rust is incredibly simple: if a function can fail, its return type is an enum of either the result of the function (in case of success) or a description of the error that happened. This enum is called Result. See:

why do i need crates for error handling?

You don't. You can 100% handle errors without any additional dependencies, and probably you should be doing that in the beginning. The crates simply add a little bit of syntactic sugar to simplify some boilerplate that you'll have to start writing as soon as your error handling gets sufficiently complex.

on Feedback for first Rust Program · c/rust · 5 pts · 141d

Welcome to Rust, I hope you enjoyed learning and using it :)

One major advice would be to run cargo clippy, which gives a lot of helpful hints. Apart from that I also have some feedback.

    40	struct VendorOuiData {
    41	    vendor_organization: String, // Vendor Organization

These comments should be doc-comments (///) so that cargo doc picks them up.

    49	fn fetch_oui_database(url_string: &String) -> Result<String, Box<dyn std::error::Error>> {

Not saying that your return type is bad, but in general you might be interested in crates thiserror and anyhow that simplify error handling.

    51	        .timeout(Duration::new(60, 0))

Duration::from_mins(1) would be much more readable.

    66	                panic!("{}", err);

You should almost never panic. Your function already returns a Result<>, so you should be using that for error handling.

    70	    } else {
    71	        // HTTP Status is not 200

Not Rust specific, but usually I recommend to handle errors first, and return from the function early. This way you reduce cognitive load on the reader, and reduce nesting of if-blocks.

   150	                let mut parts = line.splitn(2, '\t');

There's a convenient method to split in two substrings that you could have used:

let (mac_address, vendor_organization) = line.split_once('\t').unwrap_or(("", ""));

   166	                vendor_oui_data.vendor_address += line
   167	                    .trim()
   168	                    .split(' ')
   169	                    .filter(|s| !s.is_empty())
   170	                    .collect::<Vec<_>>()
   171	                    .join(" ")
   172	                    .as_str();

I would probably write a regular expression that replaces all contiguous whitespace with a single space instead.

   173	                vendor_oui_data.vendor_address.push('\n');

Aren't you trimming this new line off in line 181?

   181	        vendor_oui_data.vendor_address = vendor_oui_data.vendor_address.trim().to_string();

This is somewhat inefficient, since you'll be allocating and copying your string here.

on need help creating a package manager in c# · c/linux · 2 pts · 244d

I’ll cover item 1: start by writing a document, describing what you want to achieve: what do you mean by package, what do you mean by package manager, what features you want to have, what features you do not want to have, how you’re going to build and distribute the packages.

The reason why this is important is that a) this will be a useful reference for the implementation, b) you will learn a lot about the subject matter by trying to answer these questions, and c) you’ll learn to write such documents which is a very useful skill.

on 🔒 - 2025 DAY 1 SOLUTIONS -🔒 · c/advent_of_code · 1 pts · 249d

ah that’s just because i needed rounding towards infinity and not towards zero. In other words i wanted -10/100 to be -1 and not zero. But i couldn’t figure it out on the spot, so i just made it never negative :)