modify the state

we must radicalize the gamers

well what if you take a copy every frame and pass it through calls to a tail recursive frame function?

then again screens and keyboards are literally side effects unless you write a program which outputs the outputs at the right time

then again screens and keyboards

Impure! Banish them!

in that case, write a program which inputs the right keystrokes to the main tail calling loop

but with what if not keyboards?