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 […]

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 […]

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.

For the 2006 French robotics cup, I wrote two utility packages for GNAT, the GNU Ada compiler:

areadline: access the readline library from Ada;
aforth: embeddable Forth interpreter written in Ada (uses the areadline library).

I haven’t put a license file in them yet, but you can get them under the GNU General Public License version 2.

Before leaving for my vacation,here are two small Python libraries I wrote that may help you if you want to participate to Project Euler:

primes.py: fast prime number generation and integer factorization
pell.py: find solutions pairs to Pell diophantine equation x2-Dy2=1

This may come as a surprise, but I will today write about a programming language for which no Free Software implementation exists, the J programming language. J does not stand for the J dirty word (Java), but is the full name of the language.
I first heard about J while solving some problems on the Project […]

I feel quite ashamed of the pun on the name and the logo of my new Forth compiler…