So I tried this XP approach of first creating unittests the last couple of days. Writing the tests goes soooo slow! I was a bit surprised on how easily I could write the real functions afterwards tho. Maybe it is good. But it requires lots of tinking in advace and that's painfull and makes you wonder what you're wasting your time on since you're not actually writing code.
Apparently I haven't thought enough yet. I'm currently struggeling with the decision if I should allow to separate the numbers of the calls and the recursive calls. Practically it means this: would anyone ever want only the total number of calls or only the recursive number of calls in the report? I'm more and more tinking of not.
So appart from that issue, which will force me to modify quite a bit, I've done not too bad. I can sort data and everything. Am now working on printing. But I get confused with the above issue and technicalities involving it. Maybe I just need to look at it with a fresh mind. Maybe I'll work withouth the horrible changes.