Some days you feel it would had been better to not quit the bed.
And some days you just can't quit your bed.
Yesterday I passed all the day with a strong pain in the back, and I couldn't even go to work. I passed the morning just checking that all the doctors near me where full, and the rest of the day trying to do something useful with my laptop... until yesterday evening, when the screen of the laptop decided enough was enough, and stopped working since then.
It turns out I was not just lacking concat and reverse on Arrays. It seems that I can't even read my own TODO items. I just had toString, join, pop and push, and thus I was lacking concat, reverse, shift, slice, sort, splice and unshift.
I have implemented now all of them, and they have all of them worked at the first try, except for splice (I got wrong some indexes on some for loops on splice). O'Caml is truly an outstanding language.