Copy on modify would work, certainly. The term I was forgetting when I wrote that is “persistent” data structures, but I’m not sure whether it’s practical to im

Copy on modify would work, certainly. The term I was forgetting when I wrote that is “persistent” data structures, but I’m not sure whether it’s practical to implement persistent structures in a non-functional language like Python. https://hypirion.com/musings/understanding-persistent-vector-pt-1 https://hypirion.com/musings/understanding-persistent-vector...