Controlling roommate's music with ssh and dcop

This is rather old one, but I didn't publish it here before.

Both my roommates use Amarok as their music player. I'm OK with music they listen to for 90% of time, but their big, fat playlists hide some real monsters. And they both have a bad habit of leaving the room with Amaroks playing in shuffle mode.

This is why I created two little scripts to pause/change the song without leaving the comfort of my chair.

Here is one, for Paweł (username pavlo) and his widescreen laptop kuandatun (kuandatun it's supposed to mean "wide ass" in Chineese).


#!/bin/zsh
ssh kuandatun "/opt/kde3/bin/dcop --all-sessions --user pavlo amarok player $*"


I have kuandatun in /etc/hosts, my .ssh/config knows that it should log in as pavlo to his machine and I have my public key listed in his .ssh/authorized_keys. Now, changing shitty song on his computer is as easy as AmarokPawla next.

The less evil use of this script is getting title, lyrics or artist of currently playing song.

EDIT: this is going to be obsolete soon, when they switch to amarok2, which uses D-Bus instead of DCOP, but it's basically the same trick

Introducing Zmrok

It was neither sleep, nor science. It was pure art. Ladies and Gentleman, I present you the Zmrok colour scheme:



features:

• it looks good
  • well, I like it ;-)
• it's small:
  • it's hackable
  • it's easily portable to other editors

Source can be viewed and downloaded at my mercurial repo or vim.org.

Zmrok is Polish for twilight, check out TextMate's (or pastie.org's) twilight colour scheme if you still wonder why it's named this way ;)

Open source is great

I'm proud and happy to proclaim my Russian PLansliterated vimscript dead. Some nice guy have taken a look at it and developed a superior solution, so Russian PLansliterated shared a destiny of my pygments' lexer for Scala.

An interesting meta-solution emerges:

1. Realize that you have a quite general problem
2. Write 15-30 min hack solution to it. It may work a little crappy, but it's good if it's easy to read and extend.
3. Open source it
4. Wait...
5. Next time you'll have the same problem someone has improved your solution beyond the recognition, so you can dump the old one.

It seems that improving something that exists is psychologically easier that starting from scratch. My new slides about Scala (download them, browse the source or watch them online) were made using pygments with new shiny lexer developed by someone pissed off by quality of an old one. Open Source is great, isn't it?

Programming language idea

Well, it's an idea about programming language without a programming language.

Think about writing a script that generates assembly. It's doable. Sometimes it's even *almost* sane thing to do, eg. when working on spellchecker I've had a crazy idea about generating code that does dictionary lookup for a hardcoded word set (It's no rocket science, just compare, jump, compare, jump...). But it's so low level and not cross-platform.

I've done some C generation from Python several times (eg. to make last year's april fool's joke - it's on this blog). The problem is that C is often not flexible enough (GCC would choke on 100MB file for dictionary; TCO, call/cc and other fancy stuff is hard...). Not C, not assembly...

There is LLVM - a perfect target.

Moving on: a scripting language that would generate all this mess.

It should be very, very meta one. Like lisp, but with syntax. A pluggable one.

My idea is to write a language that would have pluggable lexer (one lexer would switch to another one when it would encounter some sequence of characters - think of reader macros on steroids), then a huge layer of macros (tons of macros. Like Nemerle). Add a lispy semantics on top of it (few orthogonal concepts that combine together nicely) and my evil plan is 10% complete.

You would be able to create literal syntax for your new, shiny DSL inside your script, then semantics that would generate optimal machine code for it and boom!

It would enable some crazy stuff. Think of all super-duper assertions library creator would be able to enforce compile time with it! You like that D enables you have optional purity control? You can add it to your script.

It wouldn't be general purpose tool (it would probably be to wired and demanding to do everyday work), but I can see applications where you have to be extremely fast (OS kernels, games) or you are very domain-specific stuff (think of all those code-generating tools like lex, bison, antlr).

More or less related things to do/blog about in future:
- DBus + gvim - a possible step towards an headless IDE
- Actor-based OS

random stuff

Beep, beep! I'm still (more or less) alive.

University takes me lots of time, which is my primary excuse for not blogging
for so long time. Projects are like gas - they fill up all available space^H^H^H^H^H time.

Interesting (for geeky enough definition of "interesting") stuff I've done recently:

• Spellchecker. It's a quite smart one -- written in python and C, it uses trie (ternary search tree) for storing dictionary. It's super-fast to load data (there are no pointers, so loading it is just one read of binary file, and you can use it).
  
  Then you can use TST to quickly (it's quicker than hashmap) check if a word belongs to vocabulary or retrieve (it's still bleeding fast) a list of words that are no further (in Levenstein's (edit) distance) than misspelled one.
  
  Then it uses longest common subsequence algorithm to get parts that don't match and compares those parts using knowledge about typical spelling errors in Polish. It can correct "grzegrzułka", "zomp" and "fzhut". In summary: it's cool.


• I'm preparing a talk about scala. It's work in progress. You can see some slides here. I'll give this talk on 3th December as a part of BIWAK


• Oh, yes, BIWAK. We (BIT science club) have started a series of talks called BIWAK.


• Oh, yes, science club. I've done some work on platform game with cool physics, but there is nothing cool to show off yet.


• I've published some of my .rc files


• Hooray new swimming pool! Hooray hiking! Hooray birthdays and weddings. Hooray real life.

Back to Poland

<terminator-voice>I'm back!</terminator-voice>
10 weeks of my internship at Resolver Systems passed like ten days. It was amazing experience - I learned a lot and I had great time. Many thanks to all my co-workers, you are great!

I had a great opportunity to attend first day of PyCon UK - it was really cool. I got some ideas I'd like to transplant to SFI festival.

TODO:
- expand this post
- LLVM
- programming language ideas
- vim + python
- more

LaTeX thoughts and lack of time

I haven't written here for quite a long time — it's because of current semester's ending. I had a lot of work to do with my projects (btw: it's one of them; another video). For every project one has to write a documentation. And I know only one way to write documents that doesn't suck hard. It's the way of TeX. I have written quite a lot of LaTeX documents last month. Here is what I learned:

• \newcommand and \newenvironment are your friends
• Making your comands and env names uppercase lets you avoid clashes with predefined ones.
  
• Try to be semantic from very beginning if it's easy. For example: you mention electronical parts or Java classes all over your document. Add \newcommand{\Class}[1]{#1} in the beginning of your document and wrap all class names with \Class{}. It would be easy do make all class names typed with some special font later on.
• If your documents take a lot of time to compile
  • break it intro few files and \input them. Comment out inputs you don't work on currently.
    
  • use draft option
    
• Thinking about writing documents in TeX as of programming helps a lot!
  • Being a nazi with DRY principle makes your document sources look very semantic and the output is prettier. You do more tweaking if you can do it in one place instead of 20 places.
  • Do the simple thing that gives you desired result. If you repeat yourself ⇒ abstract out repetition intro new command(s) and/or environment(s).
  • Refactor!

There are some things I wanted to write about, but I haven't got time. Here is my public TODO list:

• Why Eiffel standard library is so cheesy that it makes me want to write program in brainf*ck instead of Eiffel (which is quite a nice language), and what can we learn from that (in "I promise, I'll never code something similar" way of learning)
• Why hovercrafts rock and how it is like to discharge 8 Duracell bateries in 20 minutes of playing with your homemade, bluetooth controlled one. (It's much more Witek's one than mine, but still)...
  
• Hooray, yet another post about monads!
• Hooray, yet another post about Scala!
• Erlang, OOP and functional programming
• I switched to zsh
  

Maybe one day one of those will turn intro full-blown post. Maybe.