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. That’s about where I am today!

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

Splay heaps redux-imperative model

2013-01-24

I did say in yesterday’s comments that I would try re-implementing splay heaps using an imperative model with an array (Scheme’s vector) as the back end rather than a functional one with trees. Well, here is is.

Sorting via splay heap

2013-01-23

Yesterday’s post from Programming Praxis gives a new (or at least different) vantage point on one of the most common problems in Computer Science: sorting. Today, we’re going to implement a data structure known as a splay heap and use that to perform a heapsort.

Triangle Trilemma

2013-01-20

Four points, a square?) and comes originally from a Google Code Jam problem. The problem is stated simply enough

Accept three points as input, determine if they form a triangle, and, if they do, classify it at equilateral (all three sides the same), isoceles (two sides the same, the other different), or scalene (all three sides different), and also classify it as acute (all three angles less than 90 degrees), obtuse (one angle greater than 90 degrees) or right (one angle equal 90 degrees).

But once you start implementing it, that’s when things get more interesting. 😄

Decoding escaped Unicode strings

2013-01-17

In one of my current research projects involving large amounts of Twitter data from a variety of countries, I came across an interesting problem. The Twitter stream is encoded as a series of JSON objects–each of which has been written out using ASCII characters. But not all of the Tweets (or even a majority in this case) can be represented with only ASCII. So what happens?

Well, it turns out that they encode the data as JSON strings with Unicode escape characters. So if we had the Russian hashtag #победазанами (victory is ours), that would be encoded as such:

"#\u043f\u043e\u0431\u0435\u0434\u0430\u0437\u0430\u043d\u0430\u043c\u0438"

Translate CSV to HTML

2013-01-16

Yesterday’s post from Programming Praxis asks us to write a function that will read content formatted as comma-separated values and output the result as an HTML table. Their solution uses the text file database library that they posted about (which is a neat concept, you should check it out), but I think I’m going to work out the solution more directly.

Wombat IDE - It's Alive! (bug fixes)

2013-01-06

It’s alive!

I haven’t worked on Wombat in a while, but with the new semester quickly approaching, I figured that it would be a good time to take out a few of the outstanding bugs on the issue tracker. Granted, there’s still a fair few, but it’s a start.

Four points, a square?

2013-01-03

Another post from Programming Praxis. This one was originally intended for Friday but they posted it early, so I figured I would go ahead and do the same. The problem is actually deceptively straight forward:

Given four points, do they form a square?

Happy New Year

2013-01-02

Yesterday’s post from Programming Praxis asks us to build a very special sort of expression. Using the numbers 10, 9, 8, 7, 6, 5, 4, 3, 2, and 1 in that order along with the operators of multiplication, division, addition, subtraction, and concatenation, find all of the ways that we can write an expression totaling 2013. Here’s one valid solution:

109 - 8 * 7 + 654 * 3 - 2 / 1 = 2013

Parallel BF

2012-12-31

Getting a bit close to the deadline, but I think I have something that’s pretty interesting. Basically, it’s the same BF interpreter that I wrote about yesterday with four additional commands:

&	Spawn a new thread; set the current cell to 0 in the parent and 1 in the child
~	Kill the current thread
!	Send a ping on the channel specified by the current cell
?	Wait for a ping on the channel specified by the current cell

A Brainf**k Interpreter

2012-12-30

The PLT Games website has a competition going where each month there will be some sort of theme for a completely new program. The first theme is a Turing Tarpit–a language that is technically Turing complete and thus can do anything any other Turing complete language can, but is so minimal as to make doing anything worthwhile overly difficult.

Beware of the Turing tar-pit in which everything is possible but nothing of interest is easy. – Alan Perlis, Epigrams on Programming

To that end, I’ve been working on a little something special which I may or may not finish by the end of the month (yes, I know that’s tomorrow). But while I was working on it, I put together a Brainf**k (BF) interpreter which I found pretty interesting to play with.