Advent of Code is a yearly challenge with one coding puzzle a day from 1st of December until Christmas Day. The challenges are language agnostic, providing the input as a text file, and expecting a number or a string as the result of each part.
I have done the last few years in Rust, and will be continuing to use it this year. This is mostly a convenience. I have a setup that allows me to solve the puzzles in a TDD style, and publish the code and a write-up quickly. Whilst I’m more comfortable using Rust for these puzzles, I still feel I have a lot of learning to do to write Rust well and idiomatically. I considered using this year to learn Gleam, but I haven’t had the time to set up tooling, so maybe next year?
I have copied over the repo tooling from last year. This has the following features:
- A documentation site built using the
cargo doctool bundled with Rust. - This static site, built with 11ty where I can write up how I’ve tackled each puzzle.
- A GitHub Actions workflow test PRs compile and the static site builds.
- A second workflow to publish both documentation and write-ups to GitHub Pages when a PR is merged into main.
I have developed a pattern for solving the daily puzzles, which I will likely follow again this year. Usually the puzzle statement is broken into stages with examples. Those examples make for good tests for doing Test Driven Development. Idiomatically, Rust tests are in a test mod in the same file as the code its testing, so I can iterate through the steps within one file for the day. Once the tests are passing, running the same against the puzzle input is hopefully trivial. In cases where the puzzle as described hits performance issues, I have a test harness ready, which allows refactoring to a more efficient implementation.
I will usually step through the stages of solving the puzzle in the write-up article, posting the implementing function and associated test.