What feels like a million years and a lifetime ago, I wrote up a library for perlin and simple noise in Racket. Inspired by Jens Axel Søgaard’s new Sketching library (processing in Racket) and a conversation thereabout, I figure it’s about time to push noise to the raco package manager!
JP's Blog
iOS Backups in Racket: Apps
So far we’ve read backup files, parsed contacts, and parsed messages. Today we’re going to dig a little deeper and start parsing apps specifically.
iOS Backups in Racket: Messages
So far we’ve laid the groundwork, loading local iOS backups and parsed out contacts. Today let’s take another step down the rabbit hole and figure out how messages are stored.
iOS Backups in Racket: Contacts
After yesterday’s post laying the groundwork for looking into iOS Backups, today why don’t we actually start digging into one of the more interesting files: your list of contacts.
iOS Backups in Racket: Groundwork
For the last little while, I’ve been spending my spare programming time working on a slightly larger project than I normally do: a Racket library for reading iOS backups.
Basically, I want to take the mess that is an iOS backup (not particularly designed to be easy to read by other programs) and extract some information from it, backing it up in a more easily readable format.
Specifically, I would like to be able to backup:
- Contact information: Even thought they’re mostly from Facebook, it will be useful for the other parts
- Messages: These are taking up a large portion of my phone’s hard drive, mostly due to attachments. Back them up just in case12
- Photos: I’m already backing these up, but it would be nice to have it in the same process
- Application data:
- List of applications over time
- Moves: GPS location
- Downcast: List of current podcasts
- Sleep Cycle: Sleep data
- Boardgame Scorer: High scores for board games
Let it snow!
Generating omnichromatic images
Inspired half by a post on the Code Golf StackExchange and half by the corresponding website allrgb.com, today’s post tasks us with making images like this:
So what’s so interesting about that picture?
Palette Swapping
Today’s task comes from the Code Golf StackExchange. The idea behind code golf is to write a program with as few characters as possible, often rendering the code nigh on unreadable. Luckily, the same StackExchange also host popularity contests, one of which is the inspiration behind today’s post:
You are given two true color images, the Source and the Palette. They do not necessarily have the same dimensions but it is guaranteed that their areas are the same, i.e. they have the same number of pixels. Your task is to create an algorithm that makes the most accurate looking copy of the Source by only using the pixels in the Palette. Each pixel in the Palette must be used exactly once in a unique position in this copy. The copy must have the same dimensions as the Source. – American Gothic in the palette of Mona Lisa: Rearrange the pixels
A "one" line echo server using let in Racket
A recent post on Reddit caught my attention: A “One” Line Echo Server Using “let” in Python (original article). The basic idea is that you can use Python’s lambda with default arguments as a let, which in turn allows you to write a simple echo server in one line a nicely functional style.
Clockception
Let’s talk about clocks.
We can draw traditional analog clocks1:
We can draw nice digital clocks:
┌─┐ │ │ ─┐ ┌─┐
│ │└─┤ │ │ │
└─┘ │ │ ─┴─└─┘
Or we can go downright mad and make clocks out of clocks:
Even animated!
