Programming

The earliest memory I have of ‘programming’ is in the early/mid 90s when my father brought home a computer from work. We could play games on it … so of course I took the spreadsheet program he used (LOTUS 123, did I date myself with that?) and tried to modify it to print out a helpful message for him. It … halfway worked? At least I could undo it so he could get back to work…

After that, I picked up programming for real in QBASIC (I still have a few of those programs lying around), got my own (junky) Linux desktop from my cousin, tried to learn VBasic (without a Windows machine), and eventually made it to high school… In college, I studied computer science and mathematics, mostly programming in Java/.NET, although with a bit of everything in the mix. A few of my oldest programming posts on this blog are from that time.

After that, on to grad school! Originally, I was going to study computational linguistics, but that fell through. Then programming languages (the school’s specialty). And finally I ended up studying censorship and computer security… before taking a hard turn into the private sector to follow my PhD advisor.

Since then, I’ve worked in the computer security space at a couple of different companies. Some don’t exist any more, some you’ve probably heard of. I still program for fun too, and not just in security.

But really, I still have a habit of doing a little bit of everything. Whatever seems interesting at the time!

Overlapping circles

2014-01-03 in Programming

Here’s a quick little programming task that I came to via a post on L2Program (who in turn seems to have found it on Reddit). The basic idea is to take a given list of circles and to determine the area enclosed (while correctly accounting for overlap).

Edges to adjacency

2013-12-23 in Programming

Another quick one, this time from /r/dailyprogrammer:

Your goal is to write a program that takes in a list of edge-node relationships, and print a directed adjacency matrix for it. Our convention will follow that rows point to columns. Follow the examples for clarification of this convention.

Rock-paper-scissors

2013-12-21 in Programming

Quick and to the point: let’s write a program to play rock-paper-scissors¹².

Twitter puddle

2013-11-30 in Programming

This one has been sitting in my backlog for a while and its been a while since I’ve gotten to write a programming post¹, but now seems as good time as ever: Twitter puzzle

Making music, part 3: Making noise

2013-11-12 in Programming

Last week we parsed some music. That post was in a bit of a hurry, so we had to leave off a fair few important pieces (like ties and slurs for one; chords for a rather bigger one). We’ll get to them soon, but for now we want to actually get something playing back.

Making music, part 2: Taking shape

2013-11-07 in Programming

It’s been a bit, but as you may have noticed life is a bit mad at the moment. But I’ve still made some progress.

When we left off last time, we’d finished the first step towards making some lovely music with Racket: tokenization. Now we want to take those songs and form them into something actually approaching music.

Making music, part 1: Reading ABC notation

2013-10-29 in Programming

It’s been a bit since I’ve had time to post¹, but I’ve got an interesting new project that I’ve been working on. It’s a bit more complicated, ergo spread out over a few posts, but those tend to be the more interesting posts anyway, eh?

The basic idea is that I want to be able to write and play music in Racket. One end goal would be to make a library available for the C211 class to give them something else to work with (in addition to <a href="//blog.jverkamp.com"/wombat-ide/c211-image-api/">images and <a href="//blog.jverkamp.com"/wombat-ide/c211-turtle-api/">turtles). To that end, here’s my current plan of attack²:

Write a lexer for ABC notation to turn raw text into a list of tokens
Write a parser to turn those tokens into a song (for example dealing with the interactions between key signature/accidentals and meter/note duration)
Use the rsound library on Planet2 / pkg to play back individuals notes and chords
Tie it all together to play a parsed song in ABC notation using the rsound library
(maybe): Use the rsound library to save ABC files as WAV audio
(maybe): Figure out the format and save ABC files as MIDI
(maybe): Render songs as music sheets/li>

Sounds like fun! Let’s get started.

Functions as lists

2013-10-09 in Programming

Yesterday’s challenge from Programming Praxis challenges us to rebuild a data structure near and dear to any Lisper’s/Schemer’s/Racketer’s¹/functional programmer’s heart: lists. The idea presented in their sample solution uses two element vectors, directly mimicking the general internal structure of Scheme’s lists. How about we do something a bit stranger? 😄

Large scale asynchronous DNS scans

2013-09-27 in Programming

On Monday we laid out a framework for converting structures into bytes. On Wednesday, we used that to enhance Racket’s UDP and DNS capabilities. Today, we’re going to take that all one step further and scan large portions of the Internet. The end goal will be to look for DNS-based on a worldwide scale.