Digital Digressions by Stuart Sierra
From programming to everything else
I’m playing some more with the early chapters of Artificial Intelligence: A Modern Approach, looking at basic tree search techniques for the 8-puzzle. I wrote simple breadth-first and depth-first search algorithms for this puzzle in Common Lisp. Here’s the code. It’s an interesting demonstation of how inefficient these alogrithms really are. I represent the puzzle…
Ran across an interesting remark in a discussion of Microsoft hiring interviews: If I remember, a lot of MIT people back in the 70s broke the computer world into the Lisp and non-Lisp data typers. The Lisp folk took a casual attitude towards data structures – just shove them in a list, put them on…
I was looking at a problem in the early chapters of Artificial Intelligence: A Modern Approach. It’s called Vacuum World. This is a very simple agent problem consisting of a vacuum placed on a grid. The grid has only two squares, each of which is either dirty or clean. The vacuum has three actions: move…
I decide to play around with the Java logging facility. I write a simple test program: import java.util.logging.*; public class LoggingTest { public static void main(String[] args) { Logger log = Logger.getLogger(“com.stuartsierra”); log.entering(“LoggingTest”, “main”); log.info(“Info Message”); log.warning(“Warning Message”); log.exiting(“LoggingTest”, “main”); } } Compile, run, and I get this: Aug 30, 2006 10:48:45 AM LoggingTest main…
I just returned from a short vacation with a little business mixed in. On the third day of my trip, I realized I needed to check my email. My hotel had free in-room Ethernet connections, but I hadn’t thought to bring my laptop with me. No problem, I thought, since the hotel also had one…
Slashdot: War Declared on Caps Lock Key A good idea. And while we’re at it, let’s dump those silly Ctrl and Alt keys. Who uses them? F1 – F12 can certainly be abandoned, as well as that triumvirate of uselessness, Print Screen / Scroll Lock / Pause. Don’t get me started on Microsoft’s “Windows” and…
Office 2003 uses a table of 1500 colors to render the user interface. That’s 1500 different colors designers have to choose for each color scheme. Overkill? Probably. But it says something about commercial software that sets it apart from most open-source software. Despite the greater theme/skin-ability of KDE, Gnome, and friends, open-source GUIs tend to…
“Any problem in computer science can be solved with another layer of indirection. But that usually will create another problem.” —David Wheeler or Butler Lampson, depending on whom you ask I’ve seen a fair amount of press about Virtualization over the past year or so. For servers, I think it makes some sense: it would…
When I was a kid, I took piano lessons. Every day, after I couldn’t put it off any longer, I would sit down and practice a piece of music. Whenever I made a mistake, I would stop, go back to a point just before the mistake, and start again. The problem with this technique was…
This poster hangs in my cubicle. The caption reads, “If a pretty poster and a cute saying are all it takes to motivate you, you probably have a very easy job, the kind robots will be doing soon.” Besides saying “nyah nyah” to the superiors who never stay in my cubicle long enough to read…