Wow you are good 
Just changed this tiny piece of code and runtime changed from 7sec to 0.7sec
Great lesson today, thanks again!
Still I would like to understand more about :
This endless suffixing is probably explaining all the time lost to rewriting and GCing terms. Reversing once at the end will ensure O(1) adding within the tight loop and a single rewrite once the program is done.
How so is this so different to append or prepend to a list? I would think it’s just about adding a pointer to a chained list, but I think I’m lacking knowledge about how things actually work under the hood
