Thanks for the book Laurent_R and letting me know of your case-study. I may use your book to get my first contact with Perl 6.

As you say, selecting the data structure is challenging. The algorithm is there but different data structure will make it more convenient to use the algorithm in different tasks.

I am interested in Statistical Learning and in this algorithm (and Monte Carlo) which is so simple. And Perl gives us so much freedom in trying things and whipping code in no time.

I give myself joy...