Advent of Code 2023 in Rust

I'm trying the advent of code in Rust this year to learn Rust. I'm not trying to be fast and place on the leaderboards (which also require working at midnight, which I'm mostly not interested in doing), I'm trying to be somewhat elegant and learn new things in Rust. The documentation is live here.

I highly recommend loading this up in a good editor, like Visual Studio Code or VIM with the ALE plugin. It will add type information to all inferred types, autocomplete, show documentation, etc.

Formatting and linting

Use:

cargo fmt
cargo clippy --all

You should have Rust 1.74+ to use the Cargo.toml config for clippy. If you want to auto-fix anything, you can:

cargo clippy --fix --allow-dirty --allow-staged

I also looked for removable features using unused-features, both to speed up compilation and it helped removed a small dependence on unicode in regex.

Tests

Use:

cargo test

Useful flags include -- --nocapture and --bin <NUMBER> for just one set of tests.

If you have cargo-nextest (say, from brew install cargo-nextest), then cargo nextest run also works.

Running

Download the input files to input/<number>.txt. For example, input/01.txt.

Use:

cargo run -r --bin 01

(-r for release mode highly recommended for some problems, like 05!)

Docs

You can build with:

cargo docs --no-deps

Notes

This is mostly one file per project, with a few shared helpers on a small number of days. I'm not worrying about visibility or nice error handling since these are one-shot "scripts". I even played with the script feature in the nightlies (01 supports it), but I wanted cargo fmt and cargo clippy (and then cargo test), so I went with the classic project-based approach.

Features used in each vary. For example, 05 has an optional progress bar (opt-out). Over time, I've been cleaning up the older problems based on what I've learned in newer problems, so looking at the history for a file might be instructive. I started using external crates like itertools & derive_more around 10-12 or so, but backported a lot of the cleanups later. I added a few tools for several problems in the aoc2023 crate, but only a small handful use it.

A few of the crates I'm using or have used:

• cached: Python's itertools.cache basically
• derive-new: Powerful new creation (supports default, unlike derive_more's Constructor).
• derive_more: Adds useful derives not part of the stdlib (like Add)
• grid: A simple 2D array library
• indexmap: Ordered map
• indicatif: Progress bars
• intervalium/gcollections: IntervalSet
• log, env_logger, test-log: logging facilities
• num: Needed lcm in a problem.
• pest/pest_derive: A PEG parser
• petgraph / rustworkx-core: Graph tools, similar to networkx for Python
• rayon (not actively used): Easy multithreading
• regex: Input parsing via regular expressions
• strum: Powerful enum tools like conversion with strings & iteration over enums

Also see Blessed.rs, a curated list of good Rust libraries.

I added fairly extensive docs to 13 to try cargo doc. Other days have some intro text, but little in the way of inline docs.

More links:

• Solution megathreads
• Rust fast solutions (Reddit)