Advent of Code 2024

Using Deno2 and Typescript

Running a day

To run a day, run

DAY={CURRENT_DAY_NUMBER} deno task day

All days are 2 digit numbers, padded with zeros if necessary. So to run the first day, you would use:

DAY=01 deno task day

or to rerun on file changes:

DAY=01 deno task watchDay

Creating a day from the template

There is a template day to get you set up to start a problem. To create a copy of it and all files it needs, as well as rename to match the naming scheme, just run:

DAY={CURRENT_DAY_NUMBER} deno task setupDay

A note on extensions

I use prototype extensions a lot in this code to steal some of my favorite pieces from languages like Kotlin. While not a good idea in a normal application, since I am not working with other people on this codebase, let me indulge in this forbidden practice.

The biggest weird ones are:

• Object.let() - execute a function in the context of the object, then return the result.
  • Example a.let(obj => JSON.stringify(obj)) would return the JSON stringified object.
  • Example a.let(JSON.stringify) would do the same.
  • Example a.let(console.log) would log the object, then return undefined.
• Object.also(). - execute a function in the context of the object, then return the object.
  • Example a.also(console.log) would log the object, then return the original object.
  • Example a.also(obj => obj.foo = "bar") would set the field foo on the object to the value "bar", then return the original object (now mutated).