The parent poster was talking about immutability, "the early days" and copying data. I think my point was that you don't have to copy data all the time but this

The parent poster was talking about immutability, "the early days" and copying data. I think my point was that you don't have to copy data all the time but this requires a clever interpreter/compiler that you could not have run "in the early days". I'd also like to use the opportunity to say that I find those OOP vs FP posts at HN rather pointless.