Here is an originally random list (using cargo tree --prefix=depth) with some very loose logical grouping. Wide-scoped and well-known crates removed (some remaining are probably still known by most).

mime data-encoding percent-encoding textwrap unescape unicode-width scraper
arrayvec bimap bstr enum-iterator os_str_bytes pretty_assertions paste
clap_complete console indicatif shlex
lz4_flex mpeg2ts roxmltree speedy
aes base64 hex cbc sha1 sha2 rsa
reverse_geocoder trust-dns-resolver
signal-hook signal-hook-tokio
blocking
fs2
semver
snmalloc-rs

My quick notes which are tailored to beginners:

Use Option::ok_or_else() and Result::map_err() instead of let .. else.

• let .. else didn’t always exist. And you might find that some old timers are slightly triggered by it.
• Functional style is generally preferred, as long as it doesn’t effectively become a code obfuscater, like over-using Options as iterators (yes Options are iterators).
• Familiarize yourself with the ? operator and the Try trait

Type inference and generic params

let headers: HashMap = header_pairs
        .iter()
        .map(|line| line.split_once(":").unwrap())
        .map(|(k, v)| (k.trim().to_string(), v.trim().to_string()))
        .collect();

(Borken sanitization will probably butcher this code, good thing the problem will be gone in Lemmy 0.19)

Three tips here:

1. You don’t need to annotate the type here because it can be inferred since headers will be returned as a struct field, the type of which is already known.
2. In this pattern, you should know that you can provide the collected type as a generic param to collect() itself. That may prove useful in other scenarios.
3. You should know that you can collect to a Result/Option if the iterator items are Results/Options. So that .unwrap() is not an ergonomic necessity 😉

Minor point

• Use .into() or .to_owned() for &str => String conversions.
  • Again, some pre-specialization old timers may get slightly triggered by it.

make good use of the crate echo system

• It’s important to make good use of the crate echo system, and talking to people is important in doing that correctly and efficiently.
  • This post is a good start.
  • More specifically, the http crate is the compatibility layer used HTTP rust implementations. Check it out and maybe incorporate it into your experimental/educational code.

Alright, I will stop myself here.

Blog announcement.