Thoughts about computer technologies

Vala language introduction on IRC

2011-09-08T03:09:00.000-07:00

Hi,
I've lately held an talk on IRC about the Vala programming language for the Ubuntu App Developer Week. I've introduced the basics of the Vala language and its features.
You can read the log of the talk here.

Probability of a union of independent events algorithm

2011-08-09T10:29:00.000-07:00

Lately I was looking for a copy 'n paste algorithm to calculate the probability of a union of independent events that are not mutually exclusive (aka inclusion-exclusion principle in probability). Unfortunately I couldn't find any algorithm for such a basic problem.
Therefore, I decided to write the following naive algorithm which is fast enough for my purposes (O(n²) in time and space, where n is the number of events), and share with everyone:

You can find the code snippet here, sorry for not embedding it in the blog post but blogger is really boring me with snippets having broken layout.

The idea behind the dynamic programming approach starts from this observation:

Let A, B and C be independent non mutually exclusive events. Then:

P(A or B or C) = P(A) + P(B) + P(C) - P(A)P(B) - P(A)P(C) - P(B)P(C) + P(A)P(B)P(C)

Let me simplify the expression using A instead of P(A):

P(A or B or C) = A+B+C - AB - AC - BC + ABC

Notice that AB+AC+BC = A(B+C) + BC. In general:

AB+AC+AD+...+AZ + BC+BD+....+BZ = A(B+C+D+...+Z) + B(C+D+...+Z)

ABC+...+ABZ + ACD+...+ACZ+...+AYZ + BCD+...+BYZ = A(B(C+D+...+Z)+C(D+...+Z)+...+YZ) + B(C(D+...+Z)+...+YZ)

That's exactly where we exploit the dynamic programming to avoid recalculating the same expressions twice.

Edit: My effort was totally useless given that for independent events this is equivalent to 1 - (1 - pA)(1 - pB)..., which can be calculated in linear time. I even used this formula once and forgot about it :-(

Give my luck back, Firefox 5!

2011-07-23T09:13:00.000-07:00

Today I've upgraded to firefox 5, special thanks to Debian developer for packaging it. So far, everything works well and better than before, except two things (one of which I managed to tweak):

The tabs bar is higher than before. This means that the mouse must move more to reach them. This has been solved. Thanks for allowing me to put the tabs bar below back again.
The address bar no more involves "I feel lucky" search. The feature was awesome, because I often write a partial website name and I get most of the time to the right page without actually typing the whole name. Also, since we already have a search bar on the top-right, why was this feature removed? It's kind of duplicated now.

So, dear readers, do you know of any add-on so that I can have "I feel lucky" search back, before I write one? Having it on the top-right bar is good as well.

Edit: The solution is to open about:config and set the keyword.URL value to "http://www.google.com/search?btnI=745&q=" (without quotes). Thanks to Giuseppe for the hint.

Python/Ruby like generators in Vala

2011-07-09T00:42:00.000-07:00

Hello,
the post below is copied straight from here.

Here I'll show a cool snippet code making use Vala async functions and iterators for emulating Python/Ruby generators. Creating a generator is as simple as extending the Generator class and implementing the generate() method.

abstract class Generator {
    private bool consumed;
    private G value;
    private SourceFunc callback;

    public Generator () {
        helper ();
    }

    private async void helper () {
        yield generate ();
        consumed = true;
    }

    protected abstract async void generate ();

    protected async void feed (G value) {
        this.value = value;
        this.callback = feed.callback;
        yield;
    }

    public bool next () {
        return !consumed;
    }

    public G get () {
        var result = value;
        callback ();
        return result;
    }

    public Generator<G> iterator () {
        return this;
    }
}

class IntGenerator : Generator<int> {
    protected override async void generate () {
        for (int i=0; i < 10; i++) {
            yield feed (i);
        }
    }
}

void main () {
    var gen = new IntGenerator ();
    foreach (var i in gen) {
        message ("%d", i);
    }
}

You can find the above code snippet here as well.

Why I'm still using Emacs

2011-07-05T03:29:00.000-07:00

Hello,
I'm using emacs since a long time by now. Everytime I ask myself why I'm using it, given emacs certainly isn't the easiest environment for programming. So, I often tried to replace emacs with other IDEs or editors, using several extensions and so on, but I still miss these killer features in a single editor:

Pressing a key (whatever it is, TAB in emacs) correctly/smartly indent the row according to the current language.
Split view, horizontal and vertical
No horizontal scrollbar, rather wrap the text
Opening/closing files without either opening a dialog or using the mouse
Search, search and replace (also with regexp variant) without opening any dialog
Switching between buffers using the longest-common-subsequence matching, without using the mouse (i.e. I don't care about file tabs, but about switching among them fast)
Indent entire code regions
Vala, C, Python, Java, Shell, Autoconf/Automake, Make and Javascript support

So, I'm not using emacs because I love it, but because it's actually the only editor with the above features.

What I'm looking for? I'm looking for a new editor/IDE, less complex, easier to customize, having the above features plus smart completion and symbol browser.
Emacs can have completion and symbol browser as well, but managing those buffers such as speedbar suck a little, things get complicated to use and to customize.

If anybody knows of such an editor, please let me know :)

Writing binary files with bash

2011-06-02T03:04:00.001-07:00

Hello,
I'm trying to see if I'm able to write some binary file using bash. So, when writing a binary file you often want to write a number into binary format. I ended up with this simple function for writing numbers in little endian:

function num2bin() {
   printf $(printf %.$(($2*2))x\\n $1|
        sed 's/\([0-9a-f][0-9a-f]\)/\\x\1/g')|
        awk -F '' '{ printf $4$3$2$1 }'
}

The first parameter is the number to write, the second is the number of bytes (up to 4). For example "num2bin 40 4" will output a 4-byte long string containing the number 40 in little endian.

How do we use it? I wrote an example script for creating a wav file with noise (according to wav specifications) that you can read here.

Let me know if you have a simpler version of the num2bin function.

Complete variables with cd command in bash

2011-05-27T05:51:00.000-07:00

Hello,
lately I've been searching for a way to complete variables containing directories with the "cd" command in bash. This is very helpful if you have something like "cd $mydir/". This is not actually working in debian bash-completion.
Then I've realized that other commands such as "ls" actually expand variables. I looked for some "complete" combo used for "ls" but not for "cd" in /etc/bash_completion and I came out with the following:

complete -F _longopt -o default cd

Luckily, this is exactly the command needed to enable variable expansion with the "cd" command. Put that in your .bashrc after loading bash_completion and you're done.

Enforce facebook chat through SSL

2011-05-22T14:59:00.000-07:00

Hello,

since a few days facebook is supporting SSL for the chat. The problem is that it can't be enabled.

Until facebook enables this you can use the SSLGuard plugin for firefox, which enforces SSL for a list of web sites, including all facebook pages and the chat as well.

We have some good ideas for sslguard that we'd like to get in for the next releases... stay tuned.

Valag 1.2 released

2011-05-14T03:11:00.000-07:00

Hello,
I've just released the 1.2 version of Valag, the graph generator for analyzing Vala code trees. Only relevant change is the fact that it now builds against libvala-0.14.

More information and download at the Valag homepage.

Bubble sort for prolog

2011-02-24T10:30:00.000-08:00

Hello again,
this time I've found a version of bubble sort here. I wanted to provide my version, which is less iterative and, I think, more intuitive. What it does is, simply, bubble until it's sorted:

bubblesort(L1, L2) :- bubblesort2(L1,L2,unsorted),!.
bubblesort2(L,L,sorted).
bubblesort2(L1,L2,unsorted) :- bubble(L1,L3,C), bubblesort2(L3,L2,C).
bubble([],[],sorted).
bubble([X],[X],sorted).
bubble([X,Y|L], [X|L1], C) :- X <= Y, bubble([Y|L],L1,C).
bubble([X,Y|L], [Y|L1], unsorted) :- X > Y, bubble([X|L],L1,_).

Yes, the exam is tomorrow so I will finally stop annoying you readers ;)

Aptitude string for downgradable packages

2011-02-19T13:17:00.000-08:00

Hello,
I'm lately doing some tests with Debian experimental packages thus I often upgrade some packages to experimental and downgrade them back to unstable.
WARNING: Downgrading in Debian is not supported etc.

aptitude search "?narrow(?installed,?archive(experimental))" -F %p|\
sed 's,\([^ ]*\),\1/unstable,'|xargs echo

This will give you a list of experimental packages installed on your system each concatenated with "/unstable". The output can go straight to "aptitude install". I don't directly use "xargs aptitude install" because it's not interactive.

Matrix transpose with Prolog

2011-02-15T12:20:00.000-08:00

Hello,
an exam exercise requires me to write a matrix transpose method. I've written one and it took a little before I was able to define it completely in 4 rules.
I'm curious then I've found this on stackoverflow: the approach is to calculate first transposed column, then shift by one column and calculate the transpose of that new matrix.
This was one of the first solutions I've thought but I haven't realized it because I'm too lazy to create a rule for calculating the shifted matrix.

My approach is iterative thus less intuitive:

trans(M1, M2) :- trans2(M1, M1, [], M2, 0), !.

trans2([A|_], _, _, [], N) :- length(A, N).

trans2(M, [], H1, [H1|R1], N) :- N1 is N+1, trans2(M, M, [], R1, N1).

trans2(M, [H|R], L, [H1|R1], N) :- nth0(N, H, X),

   append(L, [X], L1), trans2(M, R, L1, [H1|R1], N).

Ok, apart the fact that I haven't got the time to beautify it, the code will iterate columns and for each column it calculates a row of the transposed matrix (yes, exactly what you expect a transpose method to do :P). The key is "passing" around the nth column we're looking at.
After we finish calculating a row, we restart from the first row but looking at the nth+1 column. Recursion ends when there are no more resulting rows, i.e. when we reached the end of the columns.

Bluetooth simple one-line device connection pairing with Bluez

2011-02-09T07:10:00.000-08:00

Hello,
I've written a simple Python script using the Bluez (version 4.66) stack (thanks to http://shr-project.org/trac/wiki/Using) with this usage:

python connect.py MACADDRESS PIN MOUNTPOINT

Snippet code for connect.py is here. If the device is paired, it will be removed and unmounted.

Disconnection is as easy with:

python disconnect.py MACADDRESS MOUNTPOINT

Snippet code for disconnect.py is here.

Feel free to use the code also for other services, in this case my primary concern was to mount the file system.

Rubik's Cube 3D Game in Vala/Clutter

2011-02-09T00:37:00.001-08:00

Hello,
I've written a simple program for playing with a Rubik's Cube using Vala and Clutter.

It features:

high simplicity in rotating cube slices and rotating the cube itself in a very natural manner
shuffle the cube
autosave the game

Download and more usage information at the homepage... have fun :)

Base64 and Quoted-Printable GConverters for GMua

2011-01-14T23:55:00.000-08:00

Hello,

lately I'm writing GMua for educational purposes and for evaluating Vala, whose purpose is to simplify writing Mail User Agents or simple scripts, ala Java Mail.

It currently parses IMAP (not yet complete) and has a graphical interface called Gutt (yes, inspired by Mutt) for testing.

In order to parse MIME parts with base64 or quopri content-transfer-encoding I chose to implement a couple of GConverter (will use GMime a day, maybe when they switch to gio, not yet needed) in Vala that you can find here:

I'm pretty sure there are bugs in these converters, by the way I wanted to share them :)

Valag 1.1 released, graph generator for the Vala AST

2010-12-19T04:19:00.000-08:00

Hello,

a new version of Valag, a graphviz generator for the Vala language AST, has been released.

Changes since 1.0 version:

Add --format and --prefix options.
Update to latest libvala-0.12.
Bug fixes.

This new version also distributes the xdot.py program as a viewer for the generated graphs.

More information and download at the Valag homepage.

Maja - The Vala to Javascript compiler

2010-12-17T10:42:00.000-08:00

Hello,

I've just released the first version of Maja, the Vala to Javascript compiler. The mapping is not quite complete but you can do pretty much everything you could do with javascript directly. There are (still incomplete) bindings for the qooxdoo framework and the demo browser is being ported to vala successfully.

Maja can be used in any environments, not only web browsers.

Programming in Vala saves you from lots of type safety troubles (Javascript), lot of typing (Java) and the syntax is really enjoyable as it is quite close to the Javascript model.

Usage and download at the homepage.

DuckDuckGo search engine

2010-09-15T05:16:00.000-07:00

Hello,
in this post I'd like to hint you a very nice search engine: DuckDuckGo. I've been pointed out to this by a post here on why both Google and Yahoo suck (and why Google search does more).
In older posts of mine you can find some examples on how Google search can miserably fail a search.
The main problem with the two approaches is: Google (and Bing too) sorts by popularity, Yahoo by match. So, what can happen is: Google finds something completely unrelated to what you need, Yahoo is much sensible to the keywords you put.

This DuckDuckGo search engine instead, looks up the search keywords and asks you for the meaning of the words (Yahoo phase), and then sorts it by popularity (Google phase). Especially with web 2.0 and publicity, popularity of web sites loses much more importance over the actual relationship between the meaning of the search and the web page itself.

So, as usual the conclusion is: don't use only one search engine, use multiple ones because implementation matters; don't say people "Google is your friend" because it can happen to be offensive, say instead "use your favourite search engine (YFSE)".

Debian Appreciation Day

2010-08-16T05:26:00.000-07:00

Hello,
today is the Debian birthday. For this event a Debian Appreciation Day has been prepared to thank all the Debian organization, all the contributors, developers, teams and everything related to the universal operating system. If you want to thank Debian and make developers feel loved :P here's the page: thanks.debian.net.

Using Mash with Vala

2010-07-29T06:22:00.000-07:00

Hello,
recently Mash has been released. It is a library for reading models in PLY format and creating Clutter actors from them. For reference, Blender is able to export to PLY. It means you can draw your models with Blender and use Clutter as rendering engine.
Clutter is a 3D canvas and animation toolkit while Blender is a 3D modelling suite.

What I've tested so far is porting the Monkey Viewer C example to Vala: code snippet and monkey PLY here.

That is going to be awesome, stay tuned!

Mipsdis MIPS32 disassembler

2010-07-29T02:28:00.001-07:00

Hello,
I've written a MIPS32 (Release 2) disassembler for ELF files. It is not a simple disassembler, it's mostly made for reverse engineering proprietary boxes for educational purposes. It has been successfully tested on Vodafone Station which has Broadcom binaries. These boxes don't have a sections table, therefore normal disassemblers don't work. Mipsdis instead will guess the bounds of those sections (most important ones are TEXT and RODATA for strings).

This console program outputs a friendly assembly code, whose each instruction is commented (comments copied directly from the mips specification). It also features labels for branches and symbol resolution for strings, global variables and functions.

More information and downloads here.

Idea duplicated again

2010-06-18T01:08:00.000-07:00

Hello,
I'd like to point you to this firefox extension HTTPS Everywhere (June 17th, 2010) and SSLGuard which is also a firefox extension (first released Oct 14th, 2009).

The code of the former extension is a lot more complicated and the result is not always quite the same as SSLGuard. In fact, while they support secure cookies and per-website custom rules, SSLGuard lets you add custom websites to be secured directly from a friendly graphical dialog.

You could even install both of them, apparently they don't conflict.

It's the second time decrew ideas are being duplicated. This happened sometimes ago with SSLtoHTML (ettercap plugin) and sslstrip (standalone application), but they released the code before us. Funny isn't it?

I'm not complaining about anything (I'm not saying "copy", I say "duplicate"), just clearing things out. Of course, better have more choice and more works.

Google Reader Fail

2010-05-02T12:08:00.000-07:00

Hello,
Google Reader has just wiped out my subscriptions list, which made me scream like a crazy monkey (other than cleaning up the list).Now I'm using bloglines, which looks pretty good except there's nothing like "read all items", but you must clean on each feed to see the items (any alternative to bloglines supporting this?).

But as far as I can see, I'm not the only one that lost the feeds, the difference is that I just opened the reader without any other operation.

I've also heard of MyYahoo! being a good aggregator, the only problem is that Epiphany/Webkit is broken with yahoo (no css), anybody experiencing this?

Valagtkdoc 1.0

2010-04-02T08:14:00.001-07:00

Hello,
yes... this is the nth program I'm writing in this period. I hope this is the last one :)

Valagtkdoc is a tool that integrates Vala with GTK-Doc for documentation generation.

You can find download and example usage at the homepage.

I think it's far from being perfect, and actually I haven't tried integrating it with autotools, but it shouldn't be that hard. Unfortunately, you have to somehow break the gtk-doc rule "do not run it manually" because valagtkdoc goes in the middle between gtkdoc-scan and gtkdoc-mkdb.

If anybody has a better solution, please tell me :)

Tdpkg troubleshooting and some news

2010-03-16T13:05:00.000-07:00

Hello,
lately I've received some feedback, thanks for this.

1) Is it compatible with apt? Can I use dpkg back again after using tdpkg?
The answer is... yes! You can use what you want in the order you want, and use tdpkg when you want. Take in consideration that after using dpkg (or apt) without tdpkg, then you use tdpkg the cache will be rebuilt for consistency.

2) It's not working here (Ubuntu, other distro...), doesn't create the cache.
First of all you have to be root when first running tdpkg in order to create the cache. If this didn't solve the problem you are maybe using an untested platform. Debian uses eglibc and tdpkg has been tested on i386 and amd64. Since tdpkg does wrapping around glibc calls it might happen to not wrap the right functions. If you want tdpkg to be ported to your platform please comment here with the result of these commands:
objdump -T /usr/bin/dpkg|grep open
objdump -T /usr/bin/dpkg|grep stat
objdump -T libtdpkg.so|grep open
objdump -T libtdpkg.so|grep stat

3) Should I put the alias also for apt-get and aptitude?
Yes you have to. Aptitude and apt-get bypass the shell so the only alias for dpkg won't work.

Another thing I'd like to say is that dpkg/experimental has a patch that speeds up a lot database reading by asking the kernel to cache .list files... i.e. dpkg will avoid cold start. This brings timing from 14 seconds to about 3 seconds! At all, using tokyocabinet you get 1 second. Think that including a cache inside dpkg would mean even less than 1 second.

Have fun... :)

Tdpkg 1.0 - speed up reading dpkg database

2010-03-15T13:21:00.000-07:00

Hello,
you may have noticed that dpkg takes a long time reading the database the first time you run it (e.g. through apt). This is because of the huge number of /var/lib/dpkg/info/*.list files (1700+ on my desktop machines). It can take up to 14 seconds and more at cold start to install/remove a single package.
Since 2007 in dpkg mailing list a first proposal (by Sean Finney) to using sqlite as cache has been posted, then a couple of weeks ago I reproposed it. No reply since then from the maintainers.

My first idea was to fork dpkg and only change the part about reading the list files. This means you had to install another dpkg version, and I haven't done it for two main reasons: most of people wouldn't have replaced dpkg and it'd have been too hard to maintain it.
The solution is tdpkg, a shared library that wrappes around glibc function calls of dpkg. You'll find in README to backup your /var/lib/dpkg/info but tdpkg is robust enough to not fuck it up.

Tdpkg comes with tokyocabinet (faster) and sqlite (handles concurrency better) cache backends. I've managed to bring cold startup time from about 14 seconds down to about 2 seconds. I will definitely have fun installing and removing applications back again.

Vala and Graphviz

2010-03-14T04:37:00.001-07:00

Hello,
it's often useful for Vala hackers to have a graphical representation of the code tree and control flow blocks. Therefore I've created a simple application called Valag which generates four types of diagrams using Graphviz for each state of the Vala compiler.

This is the first release, there're many things to fix and enhance (like command line options) but it is working quite good already to give support when hacking Vala.

Homepage, screenshots and download here.

Google search wrong again

2010-03-05T04:37:00.001-08:00

Hello,
sometimes ago I posted twice about google search having wrong results.
Now it happens again after a few months (it's like google breaks page weights like every 4-5 months).
The search is "debian dpkg list", I really expect the mailing list info page but after 3-4 pages of google search (and also bing this time) I couldn't find it. With yahoo search it's at the first position (lists.debian.org/debian-dpkg).

Like for the previous posts, using different search engines matters and matches your needs.

Debian/GNOME bug triage ended

2010-03-03T01:51:00.000-08:00

Hello,
I'm writing about the work done in the bug triage weekend of the Debian/GNOME team, started at 27th Feb and ended in 28th Feb.
The result is great, 167 bugs have been closed and many more have been triaged and forwarded upstream.

Thanks to everybody who contributed, especially to whom has done it for the first time (well, you can still continue working on the remaining bugs ;) ).

Secure and Decentralized Chat

2010-02-16T03:11:00.001-08:00

Hello,

I'm writing to let you know of the first release of SDChat.

It is a protocol with libraries and programs to create secure IM networks using GPG and RSA.

All the stack is written in Python but the page says it will be rewritten from scratch to provide a C API.

It features a GTK+ interface with many plugins (unfortunately audio and video are being broken due to gstreamer updates) and a simple server for routing. No installation is required.

Wondering if this can be any useful for Iranians.

Vala 0.7.10 released

2010-02-04T12:43:00.000-08:00

Hello,

I'm lately following the Vala development and finally we got a new release with plenty of bug fixes and enhancements which makes Vala even more interesting and usable as general purpose language.

Here's the announcement.

I'd like to point you to the new Vala journal, a good resource to stay tuned with Vala changes periodically.

News:

* Support coalescing operator ??.

* Support to_string and bitwise complement with enums.

* Return handler id when connecting signal handlers.

* Support struct comparison.

* Support constructor chaining in structs.

* Enforce protected member restrictions.

* Improve performance of flow analysis.

* Support automatic line continuations in Genie.

* Improvements to the .gir reader and writer.

* Add --enable-mem-profiler commandline option.

* Many bug fixes and binding updates.

Fetch web page with Vala and Soup

2010-01-24T03:04:00.000-08:00

Hello,

I'm lately using the Vala language widely. I find it a great and well designed language.

You may know I'm the maintainer of Freespeak. This program is written in Python. Now I'm rewriting it in Vala, both for providing a good and really simple API in C and for learning Vala.

I will now paste a snippet from the new freespeak code that I use for creating a cancellable asyncronous operation for fetching a web page using libsoup either with a GET or a POST method.

Here's the snippet at refactory.

Happy Holidays

2009-12-25T01:23:00.001-08:00

I wish you all a Merry Christmas and a Happy New Year!

Facebook and Berlusconi

2009-12-14T09:38:00.000-08:00

Hello,
today many people are getting subscribed (with NO authorization) automatically to this group: Sosteniamo SILVIO BERLUSCONI contro i FAN di massimo tartaglia. You have NO notification that you've been subscribed to this group.

Also consider the geographic position (screenshot) of the group contact.

Also consider that the group can't be signaled to facebook, because the feature looks like out of service.

It's clearly a mafia group, beware of!

Lua for Pythoners - Dictionary

2009-12-14T04:15:00.001-08:00

Hello,
as promised this is the second post, this time for dictionaries. The most important thing to notice is that tbl[key]=nil means deleting the entry from the table, while in python dict[key]=None is still a valid entry with None value.

Here's the snippet you can launch in a lua interpreter and this is the catalog of python dictionary examples.

Lua for Pythoners - Lists

2009-12-13T05:58:00.001-08:00

Hello,
lately I'm discovering Lua as general purpose language. Many people don't agree with lua being used as a general purpose language, many others (including a newbie like me) think Lua has such a simple syntax and powerful tables to become a full fledged language.
I use a lot of Python, so I start from here: what Python does that Lua can't do almost in the same way? Read the question as it is, don't read "what Python does that Lua can't do", it's different.

This is the first of several post series I'm writing. I'm trying to "translate" python pills in Lua + Penlight

Please consider that many things can be done really better in Lua. As I said, this is a kind of "translation". You will understand that Lua does better than Python in other things that will not be shown because the examples are made in Python.

Here's the snippet, you can run it with a stand-alone Lua interpreter.

If you know better ways of doing things like in Python please comment. Comments like 'Hey, it's inefficient! This is not the way you do things in Lua' are accepted of course but not related to the post.

Errata:
I've had some important feedback thanks to #lua people in IRC:
- Variables in Lua are globally assigned, so at least in functions you must use local
- Using table.insert in loops is slow, better use tbl[#tbl+1] assignment, and even better remember the next free position tbl[next] = element; next = next + 1

Mimaggia, cairo tester

2009-11-27T04:21:00.001-08:00

Hello,

From GNOME

I've created a simple pygtk project for testing cairo statements. It includes a sort of terminal where you write statements in a simple language. It features immediate preview of what you write.

Say it's a new format for images.
If you want to test it and see the code, ask me.

Python and RSA

2009-11-14T06:34:00.000-08:00

There are many Python toolkits for crypto, so I hope I've done the best choice (at least for now). This is a simple utility class for managing RSA keys, a sort of wrappera to the m2crypto class.

import M2Crypto

class RSA (object):
def __init__ (self, bits=1024, padding=M2Crypto.RSA.pkcs1_padding, exp=65537):
    self.bits = bits
    self.padding = padding
    self.exp = exp
    self.rsa = None

def generate (self):
    self.rsa = M2Crypto.RSA.gen_key(
        self.bits, self.exp, lambda x: None)

def encrypt (self, s):
    c = ""
    bytes = self.bits/8-11
    for i in range(0, len(s), bytes):
        c += self.rsa.public_encrypt (s[i:i+bytes], self.padding)
    return c

def sign (self, s, algo="sha1"):
    dgst = M2Crypto.EVP.MessageDigest (algo)
    dgst.update (s)
    return self.rsa.sign (dgst.digest (), algo)

def verify (self, s, sign, algo="sha1"):
    dgst = M2Crypto.EVP.MessageDigest (algo)
    dgst.update (s)
    try:
        self.rsa.verify (dgst.digest (), sign, algo)
    except:
        return False
    return True

def decrypt (self, c):
    s = ""
    bytes = self.bits/8
    for i in range(0, len(c), bytes):
        s += self.rsa.private_decrypt (c[i:i+bytes], self.padding)
    return s

Example usage:

rsa = RSA ()
rsa.generate () # generate key pair
s = "a"*2000 # test data
edata = rsa.encrypt (s)
sign = rsa.sign (s)

ddata = rsa.decrypt (edata)
assert rsa.verify (ddata, sign) == True

Debian+Apache+Tomcat+Axis

2009-10-09T06:08:00.001-07:00

Hello,
one of the courses I'm following at the university is "Laboratorio di reti
di calcolatori" which uses the technologies (really technologies?????)
listed in the post title. This is a little tutorial for making them works,
with a little script for registering .wsdd files.

- aptitude install apache2 tomcat6
- download the binaries of axis 1.x (latest is 2.x, it's not used in our course) and xerces then unpack them.
- copy *.jar of xerces into the "lib" dir of axis.
- create "/etc/tomcat6/policy.d/99axis.policy" with:

grant codeBase "file:/var/lib/tomcat6/webapps/-" {
permission java.security.AllPermission;
};

- copy the "axis" directory found under webapps of the axis binaries into /var/lib/tomcat6/webapps
- invoke-rc.d apache2 restart
- invoke-rc.d tomcat6 restart

Now go to http://localhost:8080 to make sure that Apache-Axis works.

Finally, this is the script for deploying web services (call it deploy.sh):

export AXIS_HOME="/home/lethal/ingegneria/reti/axis/axis-1_4"
export AXIS_LIB="$AXIS_HOME/lib"
export AXISCLASSPATH="$AXIS_LIB/axis.jar:$AXIS_LIB/commons-discovery-0.2.jar:$AXIS_LIB/commons-logging-1.0.4.jar:$AXIS_LIB/jaxrpc.jar:$AXIS_LIB/saaj.jar:$AXIS_LIB/log4j-1.2.8.jar:$AXIS_LIB/xml-apis.jar:$AXIS_LIB/xercesImpl.jar"
java -cp "$AXISCLASSPATH" org.apache.axis.client.AdminClient -lhttp://localhost:8080/axis/services/AdminService "$1"

In the script, you must tweak the AXIS_HOME variable to point to the unpacked axis binaries: avoid using spaces in this variable or you'll encounter several errors in terms of classpath.
Usage of the script:

sh deploy.sh file.wsdd

We're done!

Speeding up zsh completion

2009-10-07T14:23:00.001-07:00

Hello,

since I've started using zsh, a great shell with great out of the box completion, one of the most boring issues was having a really slow completion. I can understand it could be slow to get a list of packages, remote files or command line options, but also paths were often slow to be completed. After lots of searches I've ended up in adding this magic line to my ~/.zshrc:

zstyle ':completion:*' accept-exact '*(N)'

This way you tell zsh comp to take the first part of the path to be exact, and to avoid partial globs. Now path completions became nearly immediate.

Another important speed up is using the cache for packages and other stuff:

zstyle ':completion:*' use-cache on
zstyle ':completion:*' cache-path ~/.zsh/cache

If you know how to boost up options/remote files, please share :)

New GPG key

2009-08-29T05:46:00.000-07:00

Hello,
due to some synchronization problems between my desktop and laptop, unfortunately I've lost my GPG secret key. I was planning to renew my key after the SHA issues, but this way I can't neither revoke the old key nor sign the new key. So I please anybody having my pubkey to delete it:
gpg --delete-key C29A9371

I've uploaded my new key as usual so you can get it:
gpg --keyserver pgp.mit.edu --recv-keys D2C27B6B

Spadi source code

2009-08-09T11:10:00.000-07:00

Hello,
after I've written really a few docs, and cleaned up some stuff, I've published the code of both Spadi and Corraza on gitorious here. In the while, I've added support for floors and closeable views.
Help... help is needed.

Stay tuned.

Constructing a free ArchiCAD alternative

2009-08-06T04:02:00.000-07:00

Hello,
together a couple of university mates we talked about a possible free (as in freedom) ArchiCAD alternative. There are several free CAD out there but none is free for architects/engineers. The project is too big and ambitious, but I wanted to give OpenGL a shot with this excuse to learn something new.

I've started two projects:

Corraza, the OpenGL framework for editing 3d objects and exporting the scene graph to ray tracing software... think about a very very very minimal blender but as library

Spadi, the GTK+ application that runs on top of Corraza

You can find a video here to see what it can do now, after a week of development.
There's no code published at the moment, contact me if you would like to join the development.

Stay tuned.

Aruanne, pdf reporting framework

2009-07-21T23:34:00.000-07:00

Hello,
a while ago I've been talking about pango cairo and how to generate pdf with a couple of tables.
In the meantime I've worked on it, improving and enhancing new kinds of elements. This has lead to the creation of a small project, a library providing a simple framework for generating mostly PDF reports (I haven't tried to generate SVG or something else yet).

After a couple of release requests, I've found finally the time to publish a sort of working code.

Here's the git repository and here you can download the snapshot tarball.

Any patches welcome.

The less consuming radio player ever

2009-06-20T13:10:00.000-07:00

Hello,
multimedia always killed desktop performance, also audio with all such effect-based players out there. I've been using deezer for a long time, but sometimes I'm tired to see my desktop lagging.
I don't need that, I need random music from internet while I'm either programming or studying, and my computer has only 512mb ram and 2.4ghz amd64 (onLY??? yes nowadays it's a little amount).

Let's see what we can do using gst-launch:


while [ 1 ]; do wget -q -O - http://66.250.45.112:80/hard.ogg|gst-launch fdsrc fd=0 ! decodebin ! audioconvert ! alsasink; done

The URL above is a hard rock station :) The while ensures re-connection. I think performances are great, 6% cpu and 2% ram.

But there's yet a bettere solution (see comments):


mplayer http://66.250.45.112:80/hard.ogg

Syx changes web and git hosting

2009-05-29T15:45:00.000-07:00

Hello,
I'm officializing the change of web hosting and git hosting from googlecode to berlios:

The new website is up!

For several reasons, including reliability, we switched both the website and git hosting to berlios. Also the purpose of this change is to rewrite the website backend using Syx.

The mailing list and the bug tracker are still hosted at googlecode.

Some progress news in the while

We're working on a new memory management, object representation and garbage collector. On the other side the lack of time is making things harder for releasing the new version. Together with the above changes, new Smalltalk standard pieces will implemented as usual. I remind you the new code is in

the object branch.

Website: http://syx.berlios.de

GIT: git://git.berlios.de/syx

Project page: https://developer.berlios.de/projects/syx/

Render tables with pangocairo like reportlab

2009-05-27T14:22:00.000-07:00

Hello,
lately I was wondering if there was any alternative to the well known reportlab python software for creating PDF reports. I immediately thought about Cairo. The only two problems are:

Cairo doesn't create multiple pages
No support for creating tables containing text, necessary for table-based reports

I still can't realize how to achieve the first feature, but the second one could be solved using Pango layouts.

The idea is to create the cells of the table using such layouts, so that the text get wrapped etc.

Here's the Pango tables code snippet containing the necessary classes for achieving the job. Notice that the methods in the snippet often make use of Pango units instead of pixels.

Now let's use the Table class as follows: create a table with two rows and two columns, then show it twice with different background colors.

surface = cairo.PDFSurface ("test.pdf", 300, 400)
cr = cairo.Context (surface)
cr = pangocairo.CairoContext (cairo.Context (surface))

sizes = [pango.SCALE*12*10, pango.SCALE*12*10]
data = [["first test with pango tables", "seems to work correctly"],
   ["though it needs", "support for borders and spans"]]

table = Table (cr, sizes, data, pango.FontDescription ("Sans 12"))
cr.rectangle (0, 0, pango.PIXELS(table.get_width ()), pango.PIXELS(table.get_height()))
cr.set_source_rgb (0.8, 0.8, 0.8)
cr.fill ()
cr.set_source_rgb (0, 0, 0)
table.show_table (cr)

cr.translate (0, 200)
cr.rectangle (0, 0, pango.PIXELS(table.get_width ()), pango.PIXELS(table.get_height()))
cr.set_source_rgb (0.4, 0.5, 0.7)
cr.fill ()
cr.set_source_rgb (0, 0, 0)
table.show_table (cr)

Here's the result test.pdf:

Blogging from Epiphany WebKit

2009-05-18T11:33:00.000-07:00

Hello,
I've been using Midori for a while. It's a great browser: innovative and light. However all my bookmarks and data are in Epiphany. Last week the new epiphany-webkit version has been uploaded in Debian Sid and I couldn't wait to test it. I'm currently using it instead of gecko; it has still some issues but I begun living without it.

Create a GdkPixbuf from cairo surface

2009-04-26T10:40:00.000-07:00

Hello,
here's the inverted code snippet of the previous post.

w, h = surface.get_width(), surface.get_height()

pixmap = gtk.gdk.Pixmap (None, w, h, 24)

cr = pixmap.cairo_create ()

cr.set_source_surface (surface, 0, 0)

cr.paint ()

pixbuf = gtk.gdk.Pixbuf (gtk.gdk.COLORSPACE_RGB, True, 8, w, h)

pixbuf = pixbuf.get_from_drawable (pixmap, gtk.gdk.colormap_get_system(), 0, 0, 0, 0, w, h)

Create a cairo surface from a pixbuf

2009-04-25T02:03:00.000-07:00

Hello,
sometimes in the code of a couple of projects I see some hard algorithms to transform a pixbuf in a cairo surface.
Maybe most of people don't know that GdkCairoContext, contrarily to cairo_t, is created against a cairo context not a cairo surface:

surface = cairo.ImageSurface (cairo.FORMAT_ARGB32, pixbuf.get_width(), pixbuf.get_height())

cr = cairo.Context (surface)

gdkcr = gtk.gdk.CairoContext (cr)

gdkcr.set_source_pixbuf (pixbuf)

gdkcr.paint ()

Notice gtk.gdk.CairoContext (cr), which cr is not the surface. That's the key of the code snippet.

For instance this can be applied on a ClutterCairoTexture to render pixbufs in the canvas.

Awesome/other wrong keyboard layout

2009-02-27T15:12:00.001-08:00

Hello,
due to the high resource usage by Eclipse (I have to use that unfortunately because of my professor) I've temporarly dropped GNOME and now I'm using Awesome for a while.

Ok let's say the problem: the keyboard. Do you have different languages, layouts and so on among several configurations (GNOME, X, ...) and your keyboard layout is messed up with awesome?
Just do it:

setxkbmap -layout YOURLAYOUT

Where YOURLAYOUT for me is it.

I've found this utility in this mailing thread. Yet you can read that awesome is still too young and lacks some keyboard configuration features.

Have fun!

JMF and MPEG

2009-02-24T14:11:00.000-08:00

Hello,
I'm recently writing a game with Java AWT/Swing/SwingX/JMF for a university exam.
If you are using the Java Media Framework and most of the formats (all the well known and used formats) can't be handled by the library here's your definitive solution to the problem.
You will usually get "Unable to handle format: MPEG" or something like that.

How do you get rid of that and make things work? There's a great plugin named jffmpeg which handles a huge number of audio and video formats (including ogg/vob).
Just follow the instructions on the project website to install the plugins.

Alternatively you can register only the codec and demux you use from within your application code as follows (e.g. only handle MPEG video format on input):

Format[] inFormats = { new VideoFormat ("MPEG") };

PlugInManager.addPlugIn ("net.sourceforge.jffmpeg.VideoDecoder", inFormats, null, PlugInManager.CODEC);

PlugInManager.commit ();

FreeSpeak 0.3.0 has been released

2009-01-10T02:42:00.000-08:00

FreeSpeak is a free (as in freedom, developed and released under the terms of GPL) frontend to online translator engines (such as Google, Yahoo, etc.). It is written in Python, it uses the GTK toolkit and some GNOME infrastructure features.

This is a major enhancemenfts release.

Overview of Changes from FreeSpeak 0.2.0 to FreeSpeak 0.3.0
===========================================================

* Project is now hosted at BerliOS.de: http://freespeak.berlios.de

* Support for cancellating operations has been added

* Translation suggestions (open-tran) have been added

* A menubar has been added and the toolbar has been cleaned up

* The behavior of language/translation selection has been fixed and improved

* GNOME documentation has been added

* Dependencies in the configuration have been cleaned up

* Support for global keybindings has been added through python-xlib

* An introduction widget for the main window has been created

Mailbox-to-mbox

2008-12-26T10:54:00.000-08:00

Hello,
lately I've been looking for a way to convert a mailman archive to an mbox format so that I could open with mutt.
I then found a couple of scripts, but the one I've found simpler and working for my needs is mailbox2mbox.pl.
Sample usage:


$ gunzip YourArchive.txt.gz
$ perl mailbox2mbox.pl < YourArchive.txt > mbox
$ mutt -f mbox

And it simply works!
Does anybody know a method as simple as the above one but more powerful?

PS: Happy holidays!

Global keybinding on X

2008-12-21T01:52:00.000-08:00

Hello,
lately I've been looking for a way to create a desktop-wide keybinding for FreeSpeak.
I first looked into Tomboy and Deskbar source codes but the egg was too huge to be adopted, and it would have brought C dependency which isn't always nice for a Python project.
Then fargiolas pointed me to a blog post where I could find about gnome keybindings owned by gnome control center. Well that was only a mirage as it doesn't really grab the key but it's only a visual entry in the keyboard shortcuts preferences.
After a few days I've finally found a not-so-hackish solution in about one hundred lines of Python code.

Here is the snippet (download), only using Xlib and GTK+ Python bindings.

Sample usage:


def callback (keybinding):
   print 'Callback!'
   gtk.main_quit ()

gtk.gdk.threads_init ()
keybinding = GlobalKeyBinding ("/apps/appdir", "key_binding")
keybinding.connect ('activate', callback)
keybinding.grab ()
keybinding.start ()
gtk.main ()

The only problem is that it doesn't make use of GDK filters because PyGTK doesn't provide such function wrappers and there's no GDK-to-Xlib mapping available.
But yes, it works very good.

Aptitude-gtk progress

2008-12-01T14:58:00.001-08:00

Hello,
I was curious to see if aptitude-gtk was making some progress. I haven't followed the project since it's been merged into aptitude.
Well, I found it more functional and complete. Here's a screenshot showing pending packages for upgrade after an update:

From GNOME

The team is definitely doing a good job. Hopefully I'll find the time to give some help as I'm really interested in such full-featured GUI frontend.
Keep going on!

FreeSpeak gains translation suggestions

2008-11-30T03:47:00.000-08:00

Hello,
it hasn't been a long time since FreeSpeak 0.2.0 has been released. One of the TODOs for the next release was to support open-tran, and more over translation suggestions for development.
This is a screenshot of what's been included in the repository today:

From GNOME

FreeSpeak is a GNOME frontend to online translator engines.

FreeSpeak 0.2.0 has been released

2008-11-28T03:57:00.000-08:00

Hello,
after some work in these weeks now I have released a new version of FreeSpeak.

FreeSpeak is a free (as in freedom, developed and released under the terms of GPL) frontend to online translator engines (such as Google, Yahoo, etc.). It is written in Python, it uses the GTK toolkit and some GNOME infrastructure features

.

It's been rewritten almost from scratch so I think there's no need to post release notes here. Anyway you can always read what changed from the old version released a couple of years ago here.

Notice that the project homepage has been changed. The project has now moved to BerliOS.de.

Replace GTK+ with Clutter for fun

2008-11-23T12:38:00.000-08:00

Hello,
lately I was having fun with Clutter and Python. I've started by creating some Gtk-like widgets (such as GtkWindow, GtkBox, and GtkButton) in Clutter.
Well, this is the result... it's a simple example of a very poor toolkit, but it works:

Try it, it's only one .py file source code

Single app instances, Python and DBus

2008-11-16T10:01:00.000-08:00

Hello,
I'm working on FreeSpeak lately and I needed to run the application once per session, as it's got a trayicon and a notebook (maybe windows with an applet is better?)
I decided to use DBus for making the application run only a single instance; when you try to open it again it won't start another process, instead it will use the already running one.

This is how I would create a generic single app instance with dbus-python:

import dbus
import dbus.bus
import dbus.service
import dbus.mainloop.glib
import gobject

class Application (dbus.service.Object):
  def __init__ (self, bus, path, name):
    dbus.service.Object.__init__ (self, bus, path, name)
    self.loop = gobject.MainLoop ()

 @dbus.service.method ("org.domain.YourApplication",
                       in_signature='a{sv}', out_signature='')
 def start (self, options={}):
   if self.loop.is_running ():
     print 'instance already running'
   else:
     self.loop.run ()

dbus.mainloop.glib.DBusGMainLoop (set_as_default=True)
bus = dbus.SessionBus ()
request = bus.request_name ("org.domain.YourApplication", dbus.bus.NAME_FLAG_DO_NOT_QUEUE)
if request != dbus.bus.REQUEST_NAME_REPLY_EXISTS:
 app = Application (bus, '/', "org.domain.YourApplication")
else:
 object = bus.get_object ("org.domain.YourApplication", "/")
 app = dbus.Interface (object, "org.domain.YourApplication")

# Get your options from the command line, e.g. with OptionParser
options = {'option1': 'value1'}
app.start (options)

How it works?

Setup the mainloop for dbus
Request a session bus name, so that other applications (in our case another instance of the same application) can connect to it
Create a new instance at path / if the bus name doesn't exist (so we are the primary owner). If it exists, then obtain the object from dbus and call the method on the remote Application object using the known interface.
The Application.start method checks if it's already running then decide what to do in both situations.

Creating a GTK+ application this way is really easy. It only needs to use the GTK+ mainloop.
Let's suppose we want to present() the GtkWindow when the user tries to open another instance of the application:

import dbus
import dbus.bus
import dbus.service
import dbus.mainloop.glib
import gobject
import gtk
import gtk.gdk
import time

class Application (dbus.service.Object):
 def __init__ (self, bus, path, name):
   dbus.service.Object.__init__ (self, bus, path, name)
   self.running = False
   self.main_window = gtk.Window ()
   self.main_window.show_all ()

 @dbus.service.method ("org.domain.YourApplication",
                       in_signature='', out_signature='b')
 def is_running (self):
   return self.running

 @dbus.service.method ("org.domain.YourApplication",
                       in_signature='a{sv}i', out_signature='')
 def start (self, options, timestamp):
   if self.is_running ():
     self.main_window.present_with_time (timestamp)
   else:
     self.running = True
     gtk.main ()
     self.running = False

dbus.mainloop.glib.DBusGMainLoop (set_as_default=True)
bus = dbus.SessionBus ()
request = bus.request_name ("org.domain.YourApplication", dbus.bus.NAME_FLAG_DO_NOT_QUEUE)
if request != dbus.bus.REQUEST_NAME_REPLY_EXISTS:
 app = Application (bus, '/', "org.domain.YourApplication")
else:
 object = bus.get_object ("org.domain.YourApplication", "/")
 app = dbus.Interface (object, "org.domain.YourApplication")

# Get your options from the command line, e.g. with OptionParser
options = {'option1': 'value1'}
app.start (options, int (time.time ()))
if app.is_running ():
 gtk.gdk.notify_startup_complete ()

How it works?

Let's say we're running the Application for the first time, the loop begins and when it ends running is set to False, so gtk.gdk.notify_startup_complete() won't be called. Instead, if the application is already running, start() will be called on the remote object running the loop. The method then returns immediately so gtk.gdk.notify_startup_complete() will be called.
If you don't notify to the launcher that the startup is complete... guess what happens to your mouse and to your taskbar panel...

If the loop is running, the window is presented to the user with a little delay. If you don't use any timestamp, the UI interaction won't let the window have the time to be presented.

Of course, you can use DBus for many more things, like both setting options from the command line, as explained in the above code, and let other applications communicate with yours and viceversa.
Nowadays almost all systems use DBus, so it won't be a pain to add such dependency. In my opinion, it would be much more painful to use lock files, FIFO, unix sockets or whatever. FreeSpeak used such old technologies and it was a very poor emulation of what DBus already offers.

ping.fm is dead

2008-10-20T13:39:00.000-07:00

Hello,
lately I've been using ping.fm for a couple of weeks because I've found it really useful.
Today I've tried to update my status through sending a mail but I received delivery failures... I then discovered that ping.fm is dead!

FreeSpeak, a GTK+/GNOME translator

2008-10-14T14:31:00.001-07:00

Hello,
I've worked on FreeSpeak a couple of years ago, a Python/GTK+/GNOME project to translate text and web pages by querying already existing online translation tools.
PRO: It has been packed for Ubuntu and it has been publicized by a journal in Italy.
CONS: It has been discontinued until now. In fact I restarted the project and I'm doing a huge refactoring because of the ugly code I wrote in the past.

It's already working, but some features are still missing.
The new approach will allow applications to use FreeSpeak as a Python library to embed the translation widgets.

Contact me if you intend to help the project with suggestions, bug reports, critiques and coding.

How to contribute to APT

2008-10-10T09:12:00.000-07:00

Debian Get Satisfaction

2008-09-11T00:59:00.000-07:00

Hello,
lately I've found getsatisfaction, a social web2 free customer support for all companies and products.
Of course, what have I done is to look for the Debian company. Well it's there, but unused.

Easy for novice users to ask and find answers there.
You can share you ideas and get help
Report problems and get help on bug reporting
General and specific discussion
Subdivide the service in variuos products (for examples ports and distributions)

GTK Apps to replace Gnome Files

2008-09-08T10:20:00.000-07:00

Hello,
everyone knows that gnomefiles has went offline with that boring redirect to osnews.com.
Now many people is looking toward gtk-apps.org, I didn't know it before. It's looking really good.
The only problems is that I had (and I guess I'm not the only one) a few unmaintained projects on gnomefiles and they are now lost.
I'm wondering if it will be publicized a day by gtk.org to be something more official.

Where are you? Yahoo! Fire Eagle

2008-08-23T02:24:00.000-07:00

Hello,
the Twitter question was "What are you doing?". The new question is now "Where are you?"

Yahoo! has launched a sort of social application called Fire Eagle for updating your location and share it across other web services.

Cincom Industry Misinterpretations reached the 100th podcast

2008-08-16T17:07:00.000-07:00

Hello,
I'm listening to the Industry Misinterpretations podcasts (though my English is so poor to understand only a few words) and now they reached the century mark. They're managing an account on Podcast Alley.

Stay tuned!

Interviewed by Clubsmalltalk

2008-08-16T04:05:00.000-07:00

Hello,
lately I've been interviewed by the new clubsmalltalk. Hey, I know, I'm not so good with English ;)
I'm glad of this, thanks to Hernan Galante.

Vagalume, GTK+ and Last.fm

2008-08-16T03:28:00.001-07:00

Vagalume, GTK+ and Last.fm
Originally uploaded by Lethalman

I've found this great gstreamer application to listen to the last.fm stations. It works perfectly, fully functional and up-to-date. Features several IM status updates, including telepathy. It's definitely good-looking with my dark theme.
Homepage: http://vagalume.igalia.com/
Last.fm group: http://www.last.fm/group/Vagalume

Compiz with ATI RS480 on Debian

2008-08-11T13:41:00.000-07:00

Hello,
after years that compositing has been introduced in our desktop, it's finally come the time to try it.

Uninstall fglrx
My video card is not supported very well with Mesa 7.0.x, in fact I've been using the fglrx driver for a long time.... until now!
I had to manually dpkg --purge all the related packages.
Now it's better to rmmod fglrx.

Install mesa 7.1 from experimental
On #compiz-fusion some guys hinted me I should have used Mesa 7.1rc because of recent improvements on my video card. The only way to get such version was to include experimental sources.
Ok, no problem, if it doesn't work I can downgrade back to the previous one.

Upgrade xorg to experimental
But there're still problems, I had to upgrade to the latest xorg in experimental because of mesa compatibility. In fact AIGLX couldn't load DRI drivers because of missing symbols.
I had to dpkg -l|grep xorg the install the one by one. I did pray for everything to work, really.
Now backup xorg.conf and go ahead with X -configure.

Install compizconfig-settings-manager and compiz-fusion-plugins-extra
For some reason, the first time I've tried running compiz it's gone Segmentation Fault. On the IRC channel they hinted me to install the crash handler plugin to back track the error. After installing such packages, magically compiz --replace worked!
Now I have a GNOME Desktop with the Blue-Joy theme and the Avant Window Navigator.

Everything both nice and unuseful, but now I understand how eye-candy fancy stuff can change your desktop.

Before the war:

After:

iStream

2008-08-07T10:24:00.001-07:00

iStream
Originally uploaded by Lethalman

Very useful applet for listening to the radio. It lacks a perferences dialog, but it's still nice.

Gnome main menu

2008-08-07T10:09:00.001-07:00

Gnome main menu
Originally uploaded by Lethalman

Hello,
while I was playing with apt-cache I've discovered a new kind of main menu in GNOME. It's being developed by SuSE. It feels nice, robust and innovative.
The screenshot is showing the documents tab.
To install, aptitude install gnome-main-menu and add the new applet.

kqemu on Debian amd64

2008-08-07T09:07:00.001-07:00

Hello,
I've been using qemu a lot lately because I'm creating an usb hdd with debian live.
The image contains a system running postgresql, development packages for gtk and python and gnome-core . All this ends up loading in more than 5 minutes, this is really boring.

Then I begun looking for a faster virtualization system, and found KVM. Unfortunately my processor hasn't the right flag for it.

Finally I found kqemu, which is a module for the kernel that speeds up a lot qemu. I never thought it could speed up things...... so.... much!
Let's install it:

m-a a-i kqemu
modprobe kqemu

That's it, for those who owns an amd64 processor, this is the right way to use kqemu:

qemu-system-x86_64 -kernel-kqemu [your options]

You shouldn't get any error, if you do... boh.

The image now boots in 33 seconds down to the bottom init scripts, and GNOME works only with a slight delay but it's definitely a great speed up. With the real machine, I enter gnome in about 40 seconds.

Keep going the good work Qemu team, and thanks as usual to everyone who helped me on IRC.

Debian and zd1211 wifi

2008-08-06T09:08:00.000-07:00

Hello,
I'm using debian lenny and I've got these two problems:

With versions of the linux kernel prior to 2.6.20 (maybe) I could install zd1211 firmware using the module-assistant which has been now dropped from testing and unstable.
Boot process slowed down by 30 seconds and couldn't plug-in the usb pen because udev/hal screw up

What I've done is to remove the source and its created firmware, with the one shipped with testing and unstable (bug #411912):

aptitude remove --purge zd1211-firmware zd1211-source
aptitude update
m-a clean zd1211
aptitude install zd1211-firmware

Now let's fix the hotplug part, open /etc/udev/rules.d/z25_persistent-net.rules and remove similar lines:

# USB device 0ace:1215 (zd1211rw)
SUBSYSTEM=="net", DRIVERS=="?*", ATTR{address}=="00:1d:0f:b3:66:f7", NAME="eth2"

Now try to detach and reattach your usb pen and everything should magically work.

Thanks to Nss (#debianizzati), dcbw NetworkManager developer and gsimmons (#debian).

Syx gaining more stability and speed

2008-07-13T07:00:00.001-07:00

Hello,
in the new branches of Syx (an open source Smalltalk-80 implementation) we're working to try a new kind of memory management and add many features that have been missed until now to focus on other stuff.

The new faster and more modern v0.1.8 release will contain the following refactoring:

Objects will be variable-length (minumum 12 bytes on 32-bit processors and 16 bytes on 64-bit processors)
By changing the objects also the GC changed to a mark and compact GC
Threaded-switch statement to run processes
More efficient method cache (maybe a simple global cache lookup for this release)

API for primitives will only change slightly.

Suggestions for any new particular technologies are welcome.

identi.ca is worse

2008-07-03T10:35:00.000-07:00

Hello,
I'm using Twitter in this week and the API works "almost" perfectly while the website is down most of the time.
I've recently heard about identi.ca, so I decided to try it.
My first impression was bad, because I've seen many redirects of the page, and DNS changes sometimes.
But ok, I tried to register and again... I had problems. When I submitted the registration twice it just did nothing.
I then waited for a couple of hours then I've been registered to identi.ca.

Once I tuned all my account settings, the service has gone down. What happened? Too many twitterers have switched and now identi.ca is out of service? In the while Twitter has magically reopened its gate.

New debian tool proposal

2008-06-30T01:16:00.000-07:00

Hello,
this is my second post about Debian. I'm lately discovering all the tools for both managing my Debian system and creating packages.
dh_make is the first tool I've used for the "first debianization" (called so by the New maintainers' guide) which creates a basic template for your package.
Anyway after a few packagings I've seen that something redundant could be automatized further.
What I suggest is a tool that does the following stuff after dh_make has been called:

First dpkg-buildpackage -rfakeroot
Check for libraries and binaries and create new packages in debian/control
Find docs in usr/shared and modify the doc-base
Check for .desktop files and .xpm then create menu
Find info and manpages files
Obtain copyright from COPYING/LICENSE and such, authors from AUTHORS and so on
Find ITP on BTS and fill in the bug number in the changelog
Rebuild the project
Check for lintian errors and warnings and try to fix them (such as empty directories, wrong library name, etc.)

I'm sorry if I'm missing any files such as init.d or cron.d but I'm still newbie with packaging and I haven't tried all the stuff yet.
How this tool sounds to you? Would it be useful and easy to make at least for simple autotooled projects?

Syx 0.1.7 has been released

2008-06-07T14:18:00.001-07:00

Hello,
after several months a new version of Syx has been released. This release contains mostly VM changes and some changes to the Smalltalk Collections. As usual, release notes follow:

This versions enhances a new version of the interpreter, major updates to the scheduler, and as usual a lot of bug fixes. Syx left the Google Code SVN repositories because of many connection problems.

You can find informations about the new GIT repository here: http://code.google.com/p/syx/wiki/GitSource?tm=4

Installation instructions: http://code.google.com/p/syx/wiki/InstallationInstructions

API and environment:

SYX_ROOT_PATH and SYX_PLUGIN_PATH environment variables have been introduced.
Process and context creation changed.
New functions have been added for the scheduler, for manually do events iteration and adding idle functions to wake up semaphores.
Startup responsibility has been dropped from libsyx.
Added syx errors for system signals to be used with syx_signal.
Image recovering has been fixed.

Smalltalk:

Covered several standard methods for Collections, Numbers and Object printing/storing.
Error reporting from the VM now drops the exception to the Smalltalk environment when the interpreter is running.
Random class has been added.
Signal handling improvements for the GTK+ plugin.
#display family methods have been introduced for Smalltalk objects.

Interpreter:

System signal handling has been improved.
Cache hash code of Symbols.
The interpreter has been refactored to use one stack per Process.
Contexts are now created only on demand.
Optimized Symbols creation.
Signal class has been abstracted.

Parser:

The parser have been changed for handling new interpreter specifications.
Several fixes to the parser for special cases.
Fixed blocks scope.
Support <- assignment.

Image:

Image snapshot will nullify C pointers
Image format has been changed for handling new interpreter specifications.
Handle internal interpreter C pointers to be restored the right way.

Scheduler:

Different behavior of the scheduler for POSIX and Windows systems has been introduced.
Scheduler external idle sources have been added.
Asyncronous command line and GTK+ loop using semaphores. This leads to dropping readline.
A simple round robin scheduler has been added.
Dropped image saving of POSIX fd poll

Documentation:

Added lots of new comments.
Started documentation project including a manual still under development and a manpage.

Thanks to everyone contributing to the project.

See the ChangeLog for a complete list of things that changed.

Syx, GTK+ and threading

2008-05-23T14:00:00.000-07:00

Hello,
you all know that Gtk+ has locks for the GUI when dealing with the X server and prevent async events to be sent. This is done by manually acquiring/releasing the lock on Gdk. Many Gtk+ ports don't do this automatically.

Syx used gtk_main() into a thread and automatically put gdk enter/leave for each function in its wrapper. It would be somewhat ugly in Smalltalk code having to enter/leave each time.
Of course, on Windows everything leads to troubles with threads.

But Smalltalk has Processes, handled by an internal scheduler. I decided then to not create a thread but cycle through Gtk+ events in the scheduler itself. Now everything works correctly.

Difference with other wrappers? The way Smalltalk is thought let you perform multi-tasking without the need to use OS threads, which means no problems on Windows and no need to take care of the Gdk lock everytime.

In addition, I rewrote part of the Console (Smalltalk-side) to be asyncronous using Semaphores. Now you can work on widgets after you run Gtk main! A small example:

Smalltalk YX 0.1.7 is ready.
Type "help!" to get help.
> Smalltalk loadPlugin: 'gtk'!
true
> | w |
> w := GtkWindow new.
> Gtk main.
> w add: (GtkLabel new: 'hello').
> w showAll!
a GtkWindow

You can imagine the result ;)
If you want to try it out you can download the scheduler branch snapshot.

Stay tuned for next 0.1.7 release.

Syx Manual

2008-05-02T01:56:00.000-07:00

Hello,
I report the post on the mailing list below:

Hello,
with the next release 0.1.7, once I get a working interpreter and updated all the parts of Syx,
I will move output of doxygen to doc/reference and start a texinfo manual in doc/manual.

My idea is to have this kind of manual:
1) What is Smalltalk
2) Why Smalltalk YX
3) Introduction to the language
4) Introduction the Syx environment
5) COMPLETE Class and methods documentation, EACH non private method will be documented with examples
and EACH class will have usage examples
6) Embedding
7) Advanced topics, internal documentation

I know it's not the time yet for Smalltalk YX to get such documentation but I think it will be
a nice boost for the project and also for the entire Smalltalk community.
Since I don't have such fantasy now I will start directly with all except the 5th topic.

Any hint will be appreciated.
Bye.

EDIT:
The Smalltalk reference will be created automatically from Smalltalk itself.

Time for Debian

2008-04-22T11:55:00.000-07:00

Hello,
I switched to Debian lately and i think it will become my preferred distribution.
I started with Slackware, then an LFS and then Gentoo. I never found them definitive for me.

I used Slackware by compiling sources most of all, then i didn't see any reason to continue using it.

The LFS came since my new PC as a test, and as long I could maintain it I had no problems and had fun with it.

I then installed Gentoo when i got my first DSL. But the updates are slow for lack of testing, I'm on an amd64. I tried to contribute someway but for the time I've been using it I never seen a open and innovative development (not in the sense that it wasn't friendly). And also, I've seen many developers leaving the project.

In other words, I "almost" used always source-based distribution. All the time I tried other binary-based distribution also to change my way of linux-life, like OpenSUSE, Ubuntu, Kubuntu, Foresight, and so on but no one satisfied me.

Then i wanted to try Debian, hoping it was different than Ubuntu. And in fact it is!
What I like of Debian is it's very high QA, how new users deal with bugs, how stable it is, how the BTS work, how the packaging works (eventough there are lots of useful tools I still don't know), the rapid updates, the security.

The thing I dislike from other distribution is that they release new stable versions but that are not so stable at first. For example i had troubles with the package manager with both Ubuntu and Foresight. Boot problems with Ubuntu, several crashes with Foresight, and so on.

But, I don't want to say Debian is now my preferred distro (I'm still afraid of binaries), but this is the good way and hopefully the last choice. Go Debian!

Smalltalk YX toward a new interpreter

2008-04-15T02:51:00.000-07:00

Hello,
Smalltalk YX is currently working on refactoring a part of the interpreter, relative to contexts and stack management.
The current version uses one stack per process but always create contexts for each method or block entered.
The new branch, called newinterp, won't create those contexts anymore but they will be created only on-demand (e.g. thisContext). This means both less resources and garbage collector usage, and a possible speedup.

More informations on the mailing list here.

Smalltalk YX 0.1.6 has been released

2008-01-07T03:21:00.000-08:00

Hello,
as usual these release notes follows.

This is a major bug fixes release, but introduce as usual many features. First of all this release put the GNU build (autotools) as first build system, and SCons as secondary which is still useful for MingW and the WinCE port.

Full GNU build support
X11 plugin
A basic CommandLine class for parsing the command line
Basic support for handling foreign C pointers and structs/unions from Smalltalk has been added
Several fixes for building on Sparc 64 using SCons
The -e option from command line has been added
Some help and Syx status will be printed in console mode
FileStream fileIn has been fixed
Class declaration from Smalltalk has been fixed
Lexer fixes for symbols, identifier and strings
FileStream now handles FILE* instead of file descriptors and this fixed several bugs
System startup has been fixed when fileing in files
Dictionary rehashing has been fixed
Basic support for handling foreign C structs and unions from Smalltalk has been added

Thanks to everyone contributing to the project.

See the ChangeLog for a complete list of things that changed.

Google search? No thanks, Yahoo!

2008-01-05T05:00:00.000-08:00

Hello,

lately I've been searching for "maemo emulator" and "mod_python psp" and the results weren't good to me.

If you don't trust, try the above searches (without double quotes) with both Google and Yahoo. This happens with many more searches.

In my opinion, Google lately is lacking a good page weight system and therefore it breaks results showing for example mailing lists instead of more important web pages.

Conclusion? I'm using Yahoo! as my default search engine until Google fixes these troubles.

Merry Christmas

2007-12-25T01:14:00.000-08:00

Hi everyone, merry Christmas.

Happy holidays!

Hello world in console and GTK+

2007-12-17T06:11:00.000-08:00

Hello,
lately i received a request to show how to print Hello world from Syx and a small example on how to open a GTK+ window.

Here are the two examples:

Have fun!

Syx 0.1.5 has been released

2007-12-14T11:04:00.000-08:00

Hello,
after a few months of low activity due to the university, i finally released the new version of Syx. Release notes follows.

This version includes yet more features, compatibility with other build systems on different platforms, important bug fixes and a great performance boost, which will be continued in next releases. A list of the major changes:

MSVC support has been improved
ANSI C and strict ISO compilation
External declarations for C++
The ST runtime compiler has been replaced with a C-side compiler
Class creation issues from ST has been fixed
Tracebacks and error reporting have been improved
Install desktop files on GNU/Linux platforms
Support for the GNU building system has been added as an alternative to SCons
Build under MSYS has been fixed
Block ensuring has been fixed
New examples have been added such as web code browser and a simple GTK+ application
Dictionary rehashing has been fixed
A better implentation of OrderedCollection? has been enhanced
Internal profiling and gprof support at compile-time
Created one stack per process against one stack per context

This version breaks the API for creating new processes and contexts from C and ST too. Thanks for anyone who contributed to Syx.

2007-11-20T14:46:00.000-08:00

Finally ADSL then Gentoo

Hello,

i was a strong Linux From Scratch user since years.

My small city didn't have ADSL until now. ADSL came here with the Wireless technology.

OK, I've a low 256kb but it's better than a 56k, don't you think so? Then i started getting gentoo and compiling everything, and now I've got a complete Gnome desktop with all network working as well.

Yes, my first ADSL, my first distro!

Syx to run code browser over CGI

2007-11-01T04:25:00.000-07:00

Hello,
lately Dominic Letz in the Syx mailing list showed his simple version of a code browser for Syx for CGI. It has been added in the examples if you want to try it on your web server.

You can find an online working version on its site: http://dominicletz.de/cgi-bin/syx
You can also view the source code from the SVN repository: http://syx.googlecode.com/svn/trunk/examples/web/

Currently i'm not working on Syx so much because of lack of time, but remember the project is not dead and won't be.
Stay tuned, a new release of Syx is coming.

Thanks to everyone.

Syx architecture

2007-10-13T02:48:00.000-07:00

Hello,
did you forget Syx already?
After many months of inactivity (that will continue unfortunately) due to my lack of time, i created two images that briefly explains how the initialization and the scheduler of Smalltalk YX work.

The initialization is explained here: http://code.google.com/p/syx/wiki/InitArch
The scheduler here: http://code.google.com/p/syx/wiki/SchedulerArch

I hope to obtain more time to spend on Syx, i won't leave the project anyway.

Bye.

Syx on NAS Linux

2007-08-28T10:08:00.000-07:00

Hello,
on the Syx mailing list, Brian Zhou notified about yet another Syx platform compatibility.

He said Syx worked on nslu2, on both unslung (armeb linux 2.4) and slugosbe
(armeb linux 2.6) firmware.
Porting Smalltalk YX to these devices wasn't hard, in fact it doesn't need any specific patch to the sources.

Of course, would be a very good news if Syx is available in Optware.

Thanks to Brian Zhou and to everyone are currently working on Syx.

Bye.

Syx 0.1.4 has been released

2007-08-20T12:27:00.001-07:00

Hello,
release notes follow.

A more stable VM has been reached with this version. Many features have been added for both the embedding and the environment. This version also includes the "image endianness compatibility" target of the 0.2 roadmap and a lot of wrapper methods for GTK+ with a basic GtkWorkspace.
This is the list of the major changes:

Running blocking processes inside the scheduler has been fixed

Major fixes to the garbage collector, object finalization, number parsing and to the scheduler

Rehashing support for hashed collections such as Dictinoary, Set and Bag

#perform: and #copyReplace family ANSI methods have been added

Interval and StdIOStream classes have been added

Missing lexer rules for quoted symbols and double quotes in strings have been added

ZeroDivide exception check for number division

Comparing methods to String have been added

A bunch of improvements for the SyxGtk plugin

Rehash dictionaries from C

Visual Studio compilation and debugging support

Useful functions for embedding Syx have been added

Reorganized inline functions to support other compilers and use dllexport and dllimport when building the library on Windows

Inheritance for method and block objects has been fixed

rootdir and plugindir Scons options have been added

Install dependent-machine object files into libdir instead of sharedir

Option -c has been added to syx to continue the startup sequence once filed in files from the command line

Support for big endian machines has been completed

System signal handling has been added

Print a bug report to the stdout on SIGSEGV or SIGILL containing informations on the memory state, the execution state and the traceback of the active broken Process

Image recovery on SIGSEGV and SIGILL or through the syx --recovery option

Scripting header (e.g. #!/usr/bin/env syx) support on fileIn

argumentCount check for methods and blocks has been introduced

Documentation installation and uninstallation is now supported

Support for 'a' and 'w+' mode with O_CREAT flag have been added to FileStream

Several issues have been fixed for packaging binary distributions of Syx using Scons

Getopt dependency has been removed

Desktop files for Posix systems have been added

Syx changed its logo since previous version. The Windows installer will handle .st and .sim files.
Roadmap for 0.5 version includes both internal and OS-level threads based schedulers, with possibly parallel computing support.

Thanks for all critiques and suggestions, and a special thank to everyone who's contributing to Syx.

Bye.

Syx image recovering

2007-08-15T16:14:00.000-07:00

Hello,
lately Syx gained system signal handling. On Segmentation Violation or Illegal Instruction, a complete traceback of the execution state, the memory state and the active process contexts being entered is printed on stdout.

Sometimes, i had problems with Squeak while developing SqueakGtk, because i did interact with C and it was easy to get into an infinite loop or a segv.

In other words, sometimes these errors come just from one Process (in the above example, i'm talking about the Gtk main loop) that break things each time you start the same image.

In Syx, i managed to automatically create a copy of the image, appending the ".recover" extension, whenever SIGSEGV or SIGILL is signaled and then remove that broken Process from being scheduled.
Also, if this didn't work because the corruption involved the VM, you're still able to use the --recovery option from the command line.

Bye.

SyxGtk vs SqueakGtk

2007-08-11T14:56:00.000-07:00

Hello,
a friend requested me a screenshot of syxgtk, it's the first one here:
http://code.google.com/p/syx/wiki/ScreenShots.

I would like to explain how the 'asd.st' script works:
1) Create the window, and connect buttons with something like button when:
#clicked send: self -> #onClicked
2) Gtk main
2.1) This forks a process that calls a primitive
2.1.1) The primitive create a thread in which gtk_main() will run
2.2) Semaphore new wait (won't never be signaled this semaphore, it's used
just to keep the process suspended so keeping Syx up if no other process
is running)
3) Suspend the current process. This because the console actually is in
blocking mode, so we need to suspend the process. There's a way to let the
console be asyncronous, already tested using Semaphores, but won't work
with readline (any suggestion here?)

Now, we connected signals to a special syxgtk marshaller, which does the
following:

transform GValue to SyxOop

obtain the callback to call

create a new process

wait that process for being terminated (remember the callback is called within a OS thread)

These i think are pure Syx callbacks, really very easy to implement for
any other external loop.

How it differs from my old SqueakGtk? Just read:

each C call had one more redirection than in Syx, because in C calls using SWIG automatically handles self pointers by accessing instance variables

main loop had to be implemented in a Squeak-side method by doing the iteration manually

the marshaller had to forward its function to Squeak, because we can't convert from GValues to Squeak objects since we can't lookup classes

we save all that GValues in a special C-side stack

set the jump for future longjmp and call the interpreter

the main loop checks for callbacks, then obtain the list of arguments from that list of GValues and does its job

once returned from all callbacks, it's time to do the longjmp to return from the C callback

It was a pain, slow and moreover wasn't so safe to use setjmp/longjmp and a
stack of callbacks.

Bye.

Example on how to embed Smalltalk YX

2007-08-08T11:21:00.000-07:00

Hello,
Smalltalk YX is born also to be a scripting language to embed in C/C++ applications. Lately, i was looking an article which briefly explains how to use Lua with C.

Then, i decided to remake that article for Syx, and this is the result:
http://code.google.com/p/syx/wiki/ExampleEmbeddingLua

The examples in the article above can be executed if you have an updated working copy of the source repository.

Other examples can be found here. Contact me if you want to contribute to this project.

Thanks to everyone, bye.

SWIG module for Syx

2007-08-06T14:15:00.000-07:00

Hello,
lately i've been trying SWIG to test how much it can be useful to interface Syx to C/C++ libraries.
I got a good starting point with a very simple module which wraps C declarations very well. For instance, i wrapped many Glib/Gtk includes entirely without any problem.

Since writing Smalltalk YX primitives is really easy, it wasn't a pain to create a SWIG module for it. In fact, today i wrapped almost all GtkLabel functions as well.

The module is still missing C++ wrapping methods and some other typemaps, but i hope it to be available very soon for normal usage.

If anyone wants to contribute to the Syx project, please let me know.

Stay tuned for the next release of Syx.
Bye!

Syx 0.1.3 has been released

2007-07-30T08:16:00.005-07:00

Hello,
this new release of Smalltalk YX adds yet more support for other platforms (Windows CE), a bunch of bug fixes, and many features like the ST compiler. This is a list of what changed since previous release:

Fractions, division methods and some other match functions (floor, ceiling, quo, trunc, ...) have been added

Some lexer issues (quotes, minus, ...) have been fixed

Fixed garbage collection while finalizing objects

Many ANSI methods for Character have been covered

First attempt to reach endianness image compatibility

String to Number methods and viceversa have been added

Super messages have been fixed

Syntax shortucts such as Object>>#caseOf:otherwise: have been added

Fixed cascading parsing

A complete Smalltalk compiler has been added

Support for cross-compiling and with more options have been added to Scons

Save text of methods

Increased initial memory size from 20000 objects to 100000 objects

More C functions have been documented

An important issue in ArrayedCollection?>>#replace:From:To:With: primitive has been fixed

Access mode (read, write, read and write) to Streams and more methods to FileStreams? have been added

CompiledMethod? and CompiledBlock? inheritance has been reorganized

Run Smalltalk scripts from command line

New plugin to wrap native Win API to create a simple WinWorkspace

Build Syx for Windows CE with WinWorkspace running on the device

Support for user-defined startup sequence has been added

Support for wide-character strings has been added

getopt, errno, fstat, access, getenv and perror are now optional functions

Cross-compiling to Windows CE has been done with host=arm-wince-mingw32ce using CeGCC by disabling all configuration options. Endianness compatibility is not perfectly reached yet.

See the ChangeLog for a complete list of things that changed.

Smalltalk YX to run on PocketPC

2007-07-29T11:57:00.000-07:00

Hello,
Smalltalk YX is known to work on many platforms at this time. However, lately i've been working to port it on PocketPC with a small graphical workspace.
It took me about 3 days of work but now it works very well. Cross compilation has been easily done using CeGCC on Windows with just some changes in the VM.

The only problem is that Syx needs to be installed into the root device to work, it's not working in other directories, but i think this is the last problem to care about.

A plugin has been added, called WinWorkspace, which is a native Windows GUI containing a text box for both the input and the Transcript, and a DoIt button to evaluate the code. This plugin also works on Win32.
I think Syx can be easily ported to Smartphone as well without many changes.

Here you can find some screenshots: http://code.google.com/p/syx/wiki/ScreenShots

Stay tuned with the next 0.1.3 release, bye.

Smalltalk YX to compile itself

2007-07-19T10:49:00.000-07:00

Hello,
lately i've been working on a compiler for Syx in Smalltalk. Actually, it's mostly a plain translation of the C one, but works pretty nice. This is an example without using intermediate shortcuts:


$ syx
> | text lexer parser method context |
> text := 'message ^123+32'.
> lexer := CompilerLexer on: text.
> parser := CompilerParser on: text for: nil class.
> parser parse.
> method := CompiledMethod fromParser: parser.
> context := MethodContext on: method parent: thisContext receiver: nil arguments: #().
> ^Processor enter: context!
155
> EOF

Eventough it's still missing features such as cascading and optimized blocks, i hope to release 0.1.3 version very soon. The purpose is to use this compiler for the console and for files instead of the C one.

Stay tuned, bye!

Syx 0.1.2 has been released

2007-07-13T06:37:00.000-07:00

Hello,

this version of Syx has a bunch of new features added to the Smalltalk
environment, and a more stable VM. Major enhancements includes:

New compiler flags to build Syx on Mac OS

Added Sets and Bags

Refactored objects to hold both instance variables and indexed variables

Literals in methods are now constant

Added basic WriteStream

Doubled initial memory size to hold 20000 objects

Fixed ByteArray/String small integer to character conversion

Added object finalization by fixing GC transactions

Added support for infinite-precision numbers using GMP

Integer overflow checks when doing sum, difference, multiplication and bit-shift

Note that Syx can be compiled also without GMP. Eventough you use an
image containing LargeIntegers, Syx will run without problems but won't understand that
numbers.

Bye.