Largely copied from RikvanToor/aoc-rust-template, upgraded for clap v4

Advent of Code Rust template

This is a basic template you can fork and implement your Advent of Code solutions in. src/days/ contains a source file for all 25 days, where an implementation of a trait Day should be written.

pub trait Day {
  type Input;

  fn parse(input_string: &str) -> IResult<&str, Self::Input>;

  type Output1: Display;

  fn part_1(input: &Self::Input) -> Self::Output1;

  type Output2: Display;

  fn part_2(input: &Self::Input) -> Self::Output2;
}

The parsers should be written using nom.

Dev shell

A flake.nix provides a nix dev shell with the rust toolchain installed. Enter the shell by running nix develop (requires the nix-command and flakes experimental features)

Usage

First, modify the package metadata in Cargo.toml and change the current YEAR constant in src/main.rs.

Then, find your session cookie. To do so, go to https://adventofcode.com, log in, and press F12. In the "Application" tab, under "Storage > Cookies > https://adventofcode.com", copy the value of the "session" cookie. Paste it into a file named .session at the root of the project. You can now download input files. To do so, run the subcommand get-input: cargo run -- get-input 1. The 1 stands for day 1, meaning it will download the input of day 1 of Advent of Code. Alternatively, from december 1st to 25th, you can skip the day parameter, and the program will download today's input. You can also use --all instead of a day parameter to download all input files.

To run your implementation, use cargo run -- run 1 to run day 1. Just like get-input, you can skip the day parameter to run today's program, or use --all to run all days.