Dr Jekyll & Mr Hyde

Tonight, I was willing to create a while construct in Factor taking two items on the stack:

a quotation to execute when the test is true
a test quotation

For example, I wanted to be able to find the smallest power of two greater than or equal to an arbitrary number (here 34098) by doing:

1 [ 2 * […]

Today, a friend of mine told me that he was writing a Sudoku solver in Haskell. I could not resist and also wrote a brute-force one. The code is ugly (I was trying to generate as short a program as possible), but it led me to interesting thoughts.
First, here is the code. Beware, you are […]

I may be the happiest computer-science teacher in the world: in less than three months, I will start teaching a whole new class called “non-classical paradigms and languages”. The goal is to let students pursuing their masters degree discover and manipulate concepts that they haven’t had a chance to play with when using mainstream languages […]

On his blog, tickletux advocates the use of FizzBuzz to find developers who grok coding. However, this kind of test may also cause difficulties. What do you do if a candidate answers with the following (correct) C code?
#include <stdio.h>
static const char *t[] = {”%d\n”, “Fizz\n”, “Buzz\n”, “FizzBuzz\n”};
int main()
{
unsigned int i;
for(i […]

As you may already know, I’m a big fan of stack-based languages such as Forth, functional languages such as Haskell and reflexive languages such as Smalltalk. You can imagine how happy I was when I discovered Factor a few days ago: it combines all those aspects.
Today, a friend sent me someone email signature and asked […]

As an experienced programmer, I participate in many Free Software projects when time permits. I am committed to a few projects, and I frequently submit patches to random projects that I happen to bump into. I also understand the dynamics of free software: when a bug stands in my way, I often fix it myself […]

I worked a lot on rforth1 lately, a Forth compiler targetting the PIC 18f family of microcontrollers. I have added many new optimizations in order to generate smaller and more efficient code.
Let’s take an example. The Forth code below cycles through the 8 possible states of 3 leds connected to ports B5, B6 and B7 […]

When I laugh at this joke while I’ve seen it at least a dozen times already, I wonder if I’m not a little bit geeky.

The ICFP contest of this year starts with the implementation of a virtual machine. While I didn’t participate to the contest itself, I wrote one in Python and rewrote another one in Ada for performance reasons. Here is its code, released in the public domain.

As a member of the Areabot association, I participated to the 2006 French robotics competition last week. We had to develop specific software for our robot, driven by two Shix boards containing each one a SH7750R processor at 240MHz running Linux and a Stratix EP1S25 FPGA.
We decided to use Mercurial from the beginning for our […]