Processing is a java library for doing visualizations and various media related stuff. A while ago I did a Clojure wrapper for it. You can get it from github: clj-processing.

Cloak

A couple of months ago I saw examples of config files of ruby’s rake. Rake is a build tool, like ant or msbuild, but unlike those, it doesn’t involve editing XML files. And thanks to ruby’s quite flexible syntax, the resulting configuration files don’t hurt your eyes.

I don’t know ruby and didn’t really feel like learning it just for one tool. Googling for something similar to rake in the python universe didn’t yield any results.

Since I’m investing much time in Clojure lately, I decided that I might as well write something useful in it. Hence Cloak, a simplistic automation tool written in Clojure. It’s heavily inspired by rake; I had rake’s docs opened most of the time when writing the app.

Here’s how to use it. You put a file named CLOAK in your project’s directory, and in it you define tasks, like this:

(task :task-name [:other-task :another]
    (when (exists? "some.file")
        (rm  "some.file"))
    (sh "command arg1 arg2 arg3" :dofail))

Task name should be a keyword. To run it from the command line, type cloak task-name, without the semicolon (assuming cloak is the name of the shell script that launches cloak). Second argument to task is an optional list of dependencies, which can be other tasks or files. For example [:compile "classes/my.lib"]. To refer to a file, use it’s file name. Apart from regular tasks, you can specify file tasks:

 (file "index.html" ["template.xml" "content/main.txt"]
       (sh "genhtml template.xml content/main.txt index.html"))

file tasks differ from regular tasks in one detail: they compare modification time of the target and all its dependencies. Task is executed only if mtime of target < mtime of source.

Cloak is not a replacement for maven or ant. It would take me ages to reach the level of functionality of those tools. I just wanted something simple, to automate the generation of my website (among other things). So far, it’s still a work in progress but it’s usable enough for me to use it with my own projects.

Utility Libs

I’ve also put my utility libs on github. Cloak requires them (but has them in in a jar, so no need to download them separately). There’s some IO and math related stuff in there.

On a personal note, that was a good year (I finished school, among other things). On the professional level, well, I didn’t work anywhere, was too busy with my thesis. But in September I started sending out my CV and found something really nice. In Denmark.

I’m starting in January, that’s why I won’t have much time at the beginning of next year for fancy retrospectives. I’ll spend 1+ year in Denmark. I always wanted to live there, at least for a while. I mean, they invented Lego, best toy ever.

But till then, I have lots of free time and so far I’m spending it mostly on reading and programming. I’m gradually replacing Python with Clojure as my weapon of choice and I’ll post something on that topic shortly.

MathTalker has pretty steep requirements for a web app: Firefox browser and special math fonts (download links on MathTalker page). Displaying math formulas is possible thanks to ASCIIMathML library, which converts ASCII to MathML. I know about the plug-in that lets you render MathML in IE, but I decided to drop support for that browser after spending a couple of hours trying to make the UI work.

App Engine

App Engine SDK comes with a little web framework and that’s what I used. You can also use Django, but I wanted to keep things simple. The built-in framework is nothing special, but it doesn’t get in your way. What requires more attention is Google’s Datastore - their distributed database. Honestly, I used only relational databases so far (oh, and flat files…), so I had to watch one or two talks from Google IO conference to get the idea.

What pissed me off the most was lack of support for nested transactions and some bugs in existing transaction code. To run some piece of code, you have to pass a function to db.run_in_transaction(), but whenever I tried to make the code more generic (as in: not to write two almost identical functions) stuff exploded. It’s pretty bad, because creating an entity and updating a counter should be a single atomic action. But they aren’t, so you end up hoping for the best.

JavaScript

Little bit of history: At first I hated it, then I really liked it. Now I’m just using it and ignoring its deficiencies. And regarding the period that I liked JS: it was the time that JS libraries were becoming really, really good, and I was just impressed (shocked, even) that it’s possible to build anything with it without cursing like mad.

But even JS 1.7, which has generators and list comprehensions, is pretty verbose, and you can only take it so far as jQuery - the best attempt for creating domain specific language in JavaScript. Great for traversing/manipulating DOM.

Another thing: I used Emacs with js2-mode. The style of formating code encouraged (somewhat) by jQuery drives Emacs insane and beaks the indentation. At the beginning it bothered me, but then I stopped nesting function definitions and js2-mode let me do my work, and my code looked more readable. I don’t know if that was how js2-mode supposed to work or if it was just a bug, but it’s done more good than harm.

Blueprint

I’ve also tried out Blueprint CSS framework. I’ve used Yahoo’s CSS reset library before (and I don’t want to work without CSS reset ever again), but never Blueprint. It’s pretty good, but somehow feels not clean enough. I guess it provides to much defaults for my taste. But I’ll probably use it again someday.

As you can see, I got lost halfway through. But this is what you get when you try to write procedural/OO code in a functional language, using immutable data structures. Usually the right way to get out of a mess like the one above is to use map or its syntactic brother: list comprehension (Clojure’s for macro).

I ended up with a lazy list of permutations, where the laziness required zero effort from me - got that for free from the language.

I’m still stumbling while writing programming in Clojure, but not in the frustrating way like when I tried to write something of use in F#. Probably getting to know Scheme beforehand helped a bit.

I’ve entered the thesis-writing mode and that means I only allow myself to work on my projects on Saturdays. By projects I mean tasks that usually take a good couple of hours. More often a whole day.

Yesterday I finally did some work on my game. With a couple of thousands LOC it became apparent I have to write some tests, and that’s mostly what I’ve done this Saturday. I’m using TestNG.

I also have to force myself to write some PHP code for a class in the coming weeks. I was avoiding PHP for so long, but it finally got me. At school, of all places.

Linux

Lately, I’m spending much of my time on Linux. Here’s why: my laptop is three years old, but only a couple of days ago suspend and resume started working. Sort of - 1 in 5 times the machine just doesn’t want to wake up, and I have to reboot it. Other annoyances: this PulseAudio bug (pulseaudio -k and using “plain” ALSA drivers fixes it), Tracker, a desktop search app, doesn’t work (but Beagle does, I use it). Oh, and watching video on Linux sucks - I always see huge pixels and sometimes that just ruins the whole experience.

One small observation: I don’t install many apps on Windows these days (I’m not counting various dev tools). I do almost everything in the browser, which really bothers me, because the UI usually is slow etc. But on Linux, I find myself more willing to try out new apps. And some of them are really good or very promising (Gnome-do, Tasque, Glipper).

The overal feel of a modern Linux desktop environment is positive. Not quite there yet, but also not far from where it should be.

Haven’t worked much on my game. But since I started working on it, I pay more attention to what is happening in the java world. That’s how I found out about Clojure - a lisp dialect for the JVM. It was created to address many of the concurrency annoyances that occur when you write code in java (or any other language which doesn’t really promote immutability). I always wanted to learn lisp, but my understanding of the situation is that there’s lot of lisp implementations and all of them work well within their own world; interop with other languages is clunky. Clojure has all java libraries at its command, so I decided to take a look.

The only sensible programming environment for Clojure at the moment is Emacs. I’m getting more and more proficient with Vim, so learning yet another editor didn’t seam like a good idea. But I did it anyway and I’m glad that I did. The combination of Emacs + REPL completely blew my mind. I’ve used Python REPL (and the excellent ipython), but somehow Emacs + Lisp REPL is different. Hard to explain it.

I also decided to take a brief look at Scheme to familiarize myself with the syntax and basic idioms of the language. Another thing: reading SICP is on my todo list for this summer and authors use scheme there. Going through a couple of exercises in How To Design Programs resulted in one or two "Aha!" moments.

I uploaded an implementation of A* path finding algorithm in JavaScript, that I wrote a year ago or so. It took me so much time to put it here, because I couldn’t get it to work on IE properly. It still doesn’t work on IE but I don’t care - it’s just not worth my time. Anyway, since writing the code I learned that the way I render the board is really inefficient on current browsers (especially IE) - all those divs shouldn’t be created dynamically.