Another day, another problem.

This time the problem looks suspiciously like Conway’s Game of Life, or, I guess, any old Cellular automaton.

We have a map like so:

L.LL.LL.LL LLLLLLL.LL L.L.L..L.. LLLL.LL.LL L.LL.LL.LL L.LLLLL.LL ..L.L..... LLLLLLLLLL L.LLLLLL.L L.LLLLL.LL

And for each iteration:

• L symbols turn into # if there’s no # in any of the 8 adjacent cells

In the last part, we’ve finally parsed some IPv4 packets. We even found a way to filter only IPv4 packets that contain ICMP packets.

There’s one thing we haven’t done though, and that’s verify their checksum. Folks could be sending us invalid IPv4 packets and we’d be parsing them like a fool!

This series is getting quite long, so let’s jump right into it.

Now that my website is deployed as a container image, I wanted to give nix a try. I’m still doing it the old-fashioned way right now: with a Dockerfile, running cargo in a “builder” image, copying stuff out of there into a slimmer image (that still has an Ubuntu base, even though distroless images are a thing now).

But why?

I was mostly interested in nix because some parts of my website have pretty big native dependencies. futile itself mostly relies on sqlite3 and some JS engine (used to be quickjs, currently duktape because MSVC Windows builds). But the asset processing pipeline, salvage (which I’d like to integrate with futile at some point) has a bunch more!

There’s one thing that bothers me. In part 1, why are we using hyper-staticfile? Couldn’t we just use file:/// URLs?

Well, first off: showing off how easy it is to serve some static files, even in a “scary” language like Rust, is just not something I could pass up.

But also: think about distributing salvage as a tool. Will we want to distribute all those HTML/CSS/JS/font files alongside it?

Putting thoughts in bits

I think about lots of things but when it comes down to writing them, drawing them, implementing them, it’s not that easy. Even with years of practice in each of these trades, it’s still an uphill battle.

Which is why I am not going to read that article after I wrote it and will go straight to publication.

Not assuming nobody cares

Up until now, we’ve been loading a single ELF file, and there wasn’t much structure to how we did it: everyhing just kinda happened in main, in no particular order.

But now that shared libraries are in the picture, we have to load multiple ELF files, with search paths, and keep them around so we can resolve symbols, and apply relocations across different objects.

Welp, I did it again - I released an album: it’s named *andfall, a play on the word “landfall”, and I wrote it in one week-end, for @McFunkyPants’ entry in the Ludum Dare 33 game jam.

It’s my first solo album, the previous ones were collaborations with @bigsylvain and @geckojsc. It feels a bit weird to release an album alone - there’s nobody to blame for the flaws, and nobody to praise for the good parts!

The Advent of Code is not a sprint: it’s a marathon: sometimes you’ve got to stop and smell the roses.

I… what? That’s not.. have you done a marathon before?

No, and I haven’t taken any creative writing classes either, I think you can tell. Anyway: Day 8 was a bit aggravating for me. In 2020 I gave up AoC after Day 14 I think, and then I skipped a year. It doesn’t help that it overlaps some holidays and stuff, but!

Part 1

Let’s tackle the day 4 challenge!

In this one, we get an input like this:

2-4,6-8 2-3,4-5 5-7,7-9 2-8,3-7 6-6,4-6 2-6,4-8

Each line has two ranges: the first line has ranges containing 2, 3, 4, and 6, 7, 8. We must count how many pairs have ranges where one fully contains the other.

In Rust, we can express this with “inclusive ranges” (std::ops::RangeInclusive), and those implement Iterator, so we can do: