I sold you on some additional functionality for catscii last chapter, and we got caught up in private registry / docker shenanigans, so, now, let’s resume web development as promised.

Adding geolocation

We kinda left the locat crate stubby, it doesn’t actually do any IP to location lookups. It doesn’t even have a dependency on a crate that can do that.

I try to avoid doing “meta” / “behind the scenes” stuff, because I usually feel like it has to be “earned”. How many YouTube channels are channels about making YouTube videos? Too many.

Regardless, because I’ve had the opportunity to make my own mistakes now for a few years (I started doing the video thing in earnest in 2019), and because I’ve recently made a few leaps in quality-of-life re: shooting and editing video, I thought I’d publish a few notes, if only for reference for my future self.

Haven’t blogged in a while. Life’s fine, project are a-plenty, but I just wanted to make a more lasting post about one particular issue that struck me as funny when programming Paper Isaac.

Bugs, bugs, bugs

What’s infuriating when letting others play an early prototype is that you hear constantly the same things. Some bugs are non-trivial to fix, some you’re just not motivated to fix now… sometimes you just have your head elsewhere, gotta focus, or are elbow-deep in some other piece of code and the damn walls can wait.

It’s time for the Day 14 problem!

After the hassle that was Day 13, I hope this time we’ll have a relatively chill time. And, at least for Part 1, that is true.

Our input looks something like this:

mask = XXXXXXXXXXXXXXXXXXXXXXXXXXXXX1XXXX0X mem[8] = 11 mem[7] = 101 mem[8] = 0

mem is our memory. Our addresses are 36-bit wide, but as you’ll see, that doesn’t matter much.

In the two years since I’ve posted I want off Mr Golang’s Wild Ride, it’s made the rounds time and time again, on Reddit, on Lobste.rs, on HackerNews, and elsewhere.

And every time, it elicits the same responses:

• You talk about Windows: that’s not what Go is good at! (Also, who cares?)
• This is very one-sided: you’re not talking about the good sides of Go!

Alright! The day 12 puzzle involves path finding, and it seems like a good time to lean more heavily on the WASM embeds I’ve set up for the previous parts.

Let’s start by setting up the types we’ll want!

Types and parsing

Our input is a heightmap, like so:

Sabqponm abcryxxl accszExk acctuvwj abdefghi

Where 'a'..='z' is a square with a given elevation (from lowest to highest), S is the start, and E is the end.

I’ve been working on the itch.io desktop app for about a year now, so I thought I’d make a quick recap:

At the time of this writing, the app has been downloaded about 460K times (including updates). Not counting the back-end, the app and its various components are made up of around 100K lines of code (mostly javascript and golang), most of which is open-source.

Documentation in ooc land has sucked for quite some time. The standard response is pretty much: “use the code, Luke!” — which is fine when doing small projects that don’t matter much, but not so when you want to get serious.

So when a newcomer, beoran, asked how to generate documentation, and later told us he got NaturalDocs to work, naturally, I had to see for myself how well it worked.

So far, we’ve seen many ways to read a file from different programming languages, we’ve learned about syscalls, how to make those from assembly, then we’ve learned about memory mapping, virtual address spaces, and generally some of the mechanisms in which userland and the kernel interact.

But in our exploration, we’ve always considered the kernel more or less like a “black box”. It’s time to change that.