ByteLabs

Do you have many research papers on your hard drive and a hard time to find the right one? Maybe Papers can help!

Only by accident I stumbled over Papers. As iTunes helps you to effectively manage your big collection of music, Papers helps you to keep up with a large collection of research papers. Of course there are many other features as well, but you best check them out yourself.

Today I finally went ahead and upgraded Ghc to version 6.6.1. On Max OS X Tiger I additionally needed to install the GNU-Readline Framework as described in this post. The installation went really fine but when trying to link executable programs ld would throw up and say something along the line:

• ... the table of contents for *.a archives are out of date and that ranlib(1) should be re-run.

Oh well, life is imperfect but the following solves the problem:

$ cd /usr/local/lib/ghc-6.6.1/
$ sudo sh -c "ls *.a | xargs ranlib"

If your running services are cranked up by SystemStarter and you want to quickly disable them, it is enough to create a .disabled file in the respective directory to stop SystemStarter from starting that service. Thus if I wanted to disable the automatic startup of my PostgreSQL database, I would create the following file:

$ sudo touch /Library/StartupItems/PostgreSQL/.disabled

Funny enough I could not find any official documentation apart from the following blog entry for this.

Finally I managed to partly migrate most of my photos to the new servers. So the all new shiny gallery is available over here. Right there you can also find the latest pictures from our last two hiking trips to Hallstadt, and to the Schoberstein.

My last blog entry was… ages ago. But anyway! ;) It is May now, it’s getting cold over here in Australia and at the moment it is cold enough to have a fire. Today is going to be a long day, I still have to do my Maths homework, and it is a lot and it is due tomorrow… And we got all our Exams back.

English
I am pretty desappointed. I passed, 34 out of 60 points… that is 56%!!! And that is the worst result I ever had here in Australia.
But there is a good excuse for having just 56%... hehe I had my English Exam on Monday, my first school day. I came to school and everyone was excited and everyone asked me if i learned something for the exams. I was just like “What?” Anyway, English was my first exam… I wasn’t prepared at all. But i passed! (at least that…)

Drama
My second Exam and I got one of the best marks in class. 33 our of 40 – 82.5%! And I had just one day to learn this whole pink book by heart. Stanislavski’s, Berthold Brecht’s, Antonin Artaud’s and Growtowsky’s acting techniques and how they taught their actors to act.

Growtowsky for example always tried to include the audience into the play. He wanted them to feel comfortable and involved. Berthold Brecht did the completely opposite thing. He wanted the audience to see the play as a narration of a happening. He tried to alienate the play with his so-called “Verfremdungseffekt”. Brecht used bright stage lighting to seperate the audience and the actors, he hardly used any stage supplies. The actor had to narrate the whole play, hardly any “acting”. Antonin Artaud was one of the first playwrights who thought, that acting with facial expressions and emotions is more important than acting through words. So did Stanislavski. Stanislavski taught his actors to use their “emotional memory” to remember of all the emotions they felt, which would suit their characters, and than to go through the emotions again and again, till they can reinact them.

Maths – Standard
My next exam on Tuesday, after Drama, was the Standard Maths Exam. I passed! Thank god… with 86% and that is pretty good. Got an award. =3

Maths – Extension
Not that good though, but I still passed. 68% – very disappointing… I simply didn’t get some of the examples, didn’t understand some words and that ruined my whole exam, but doesn’t matter…

Anyway… this is my fourth month in Australia and I still love it! I’m not homesick, still not… but who knows, hopefully all my friends and especially my host family won’t get sick of me! hehe

Wish you a pleasant afternoon and evening. Have a nice bath and forget about work, just relax for a few seconds and enjoy life! That’s what it’s all about ;)

best wishes from the other end of the world xoxo ines

If you push something hard enough, it will fall over. I have been pushing my horizon a bit further and it fell, as it were in the right direction.

The reason why it was so quiet here can be totally attributed to my newly discovered passion for Haskell. I do not really want to state all the language features and why it is such a beautiful language since that is described in many other places in much greater detail than I would wish to do here. On the contrary! What I want to is to outline my learning curve a bit, which might be beneficial for someone else who is seeking to learn Haskell.

My first contact with Haskell was at the University of Edinburgh and Simon Thompsons book Haskell – The Craft of Functional Programming was a very good companion at the very beginning. It also offers a very good description of Haskells type system and includes many many examples. While working through the book many of Haskells features are conveyed by the author. If you have never really used a functional language before the book also teaches you many programming idioms used in the declarative world of functional programming.

The only part I didn’t really like about the book was the chapter about Monads. You are surely asking yourself what in the world monads are and why one needs them? The short story is that monads in Haskell are used to ‘safely‘ perform side effects while maintaining all the nice features a pure functional language with lazy evaluation provides.

Having said that, it is really necessary to grok the concept of monads in order to enjoy the full beauty of Haskell. In my opinion the paper Tackling the awkward squad: monadic I/O, concurrency… by Simon Peyton Jones has one of the best explanations of what monads are. Also Phil Wadler has many nice papers about monads from which I would personally recommend the paper “Imperative functional Programming”. Armed with this kind of information, it should not take long for your brain to comprehend monads.

Haskell has a very powerful type system. Coming from the imperative world I wasn’t really able to comprehend the power of it. Here another very good book, namely Types and Programming Languages offered a great introduction into the topic.

Of course there are many other very good books and papers out there but for the moment this should suffice. Happy hacking with Haskell :-)

Forget about Apples all new Airport Extreme and all the other wireless AP products, as soon as this board will be released and ready for sale, I will replace my Firewall and WLAN access point with it, leading to a dramatic noise reduction in my living room, and rock solid stability and security because it will run OpenBSD – there is NO other alternative OS for such a task!

My code generator which is still in the prototyping and experimentation phase does a lot of recursive tree traversals which is quite obvious since it needs to match tree patterns and emit code for abstract syntax trees (AST).

Especially during the code emission phase which does a top down left to right tree traversal it would be nice to recursively evaluate child nodes of an AST in parallel if the evaluation of the child nodes does not yield any side effects. The following paper nicely describes how to transform standard multi-way recursive methods into parallel mutli-way recursive methods in Java.

The transformation described is quite simple and works well for direct recursion. However, due to the attribute type grammar I want to use for my tree pattern matching code generator and the way most tree patterns are augmented with semantic actions, it seems that it would cause a bit of a mess, or at least require a lot of careful thinking how to integrate such parallelism into the tree pattern matching grammar and the code generator which is produced by the grammar specification.

Unfortunately right now this idea can not be assigned a high priority and must be post-poned…

Today I took a look at Klaus Hartkes web page and found that he maintains a collection of valuable links about Programming Languages! Very nice indeed!

According to this blog entry, it is possible that the window focus follows the mouse between terminal windows by typing the following in the Terminal:

defaults write com.apple.Terminal FocusFollowsMouse -string YES

Now quit and restart the Terminal to let the changes effect.