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!

Wombat IDE - Pair programming

As I mentioned once before, I’ve been meaning to add the ability to share screens between different users. I spent a few hours yesterday evening, trying to get everything working correctly in the new setup. So far, I have messages sent and received (encoded using a Public Domain Java Base64 library) between a host and one or more clients, all with an easy enough to use GUI built right into Wombat:

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Wombat IDE - Threads are *fun*

Threads can get all sorts of interesting sometimes. And fun to debug. Essentially, whenever the user would restart the Petite process (using the Stop button) a new output thread would be spawned. There wasn’t any problem with the output being duplicated or lost–I already had locking in place to prevent that–but what would happen is that the threads would interleave the output, scrambling output nicely.

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Wombat IDE - Enhancements and forward thinking

A few minor enhancements with the new Petite-based builds: Start case sensitive by default Added a library directory in preparation for the new C211 libraries Added code to prevent gensym printing (makes records more readable in general) Re-added the C211 tree library (except for draw-tree), it’s pure Scheme but the API has remained the same I still haven’t pushed an official build for the students to actually use, but we’re getting closer.

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Wombat IDE - Bug fixes galore!

Bug fixes:

  • Added the ability to cancel when saving on close
  • Fixed Stop with Petite
  • Fixed an issue where the cursor wouldn’t be at the end on up arrow
  • Updated the launcher to actually exit in all cases, including errors on startup
  • Fixed build process for Petite sub-directories
  • Altered the Launcher to download zip archives and unzip them rather than grabbing the executable directly
  • Set the executable bit on unpacking files from zip so that Petite actually works on Linux and OSX machines

Wombat IDE - Shutdown hook

An interesting feature: Runtime.getRuntime().addShutdownHook(new Thread() { public void run() { NativeProcess.destroy(); } }); (NativeProcess is the Petite Process object.) Theoretically, this code will run whenever the Java Virtual Machine shuts down normally, so if it crashes there will still be problems (although it’s harder than you might think to get the JVM to crash unless you’re specifically trying to do so). I just thought that was neat and should avoid some of the problems that Odete was having with zombie processes.

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Wombat IDE 2.x

The new version of Wombat has been uploaded. Rather than the Java Webstart based 1.x version, the new version has a built in auto update system. All that you need is the launcher (you can get it here) and everything should go from there. You should automatically get at least version 2.20.3. From now on, the 1.x line (using Webstart and Kawa) will no longer be updated and all updates will be to the 2.

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Wombat IDE - The first Petite versions

I started the basic conversion to petite back on 13 January, but I finally managed to get everything working today. To start the conversion, the first thing that I did was split everything into three active projects:

  • ide - contains the GUI code and code to whatever Scheme system I use
  • launcher - contains the code to find the correct version of the IDE and launch it and also to update to the latest version(s) automatically
  • petite - contains the bindings to Petite and can actually act as a stand-alone command-line REPL

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Wombat IDE - Yeah... Maybe I was crazy

So I started let today. And let me tell you (no pun intended) that is one sticky function to work with, once you get the entire family involved. You have let, let*, let-values, letrec, and named lets, along with all sorts of combinations thereof. I actually made it about 90% through all of these (just a few bugs to work out in letrec) before I realized that this was perhaps more than I actually wanted to do for the public version of Wombat.

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Wombat IDE - Call me crazy...

…but I’m working on my own implementation of Scheme in Java. Don’t get me wrong, Kawa has been great for what it was, but there are just enough things that are just slightly off that I want to make the change.

Essentially, it all comes down to the fact that the autograder and other tools still run on Chez Scheme. Over the semester, there have been an increasing number of problems where the two don’t quite agree and so there has to be special cases done by hand. Optimally, I would like Wombat to have 100% compatibility with Chez Scheme (at least in the parts that the students use), but I don’t think that I’m going to be able to get there with what I’m doing. There’s already about 1000 lines of code to make them work better together and it’s only likely to get longer. At some point, I might as well just write my own Scheme. So here goes!

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Wombat IDE - C211 Matrix Library

For the final exam, I’ve added a matrix API. The students are supposed to have implemented this, but we know that haven’t, so this way they can either use their version or mine.

Matrix API (Edit: The most up to date Matrix API can be found here):

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