I’ve found emulators to be a pretty poor first project for rust specifically for the reasons you alluded to: That you need to know to write it without heap allocation (or other hoop jumping so long as you avoid juggling lifetimes) when so much literature and example emulator code doesn’t do this is a recipe for a bad experience. Ask me how I know.
If you’re going to write an emulator in this style, why even use an imperative language when something like Haskell is designed for this sort of thing?
These emulators already exist in basically every language, so why do anything? The point is the journey, which doesn’t need to be the shortest, most optimal path possible.
I’m saying it’s not optimal for learning the language, not that it’s not worth doing. I’ve worked on 3 different emulators for fun over the last few years, my first in rust. It was a bad experience for learning rust because I was following prior art which relied heavily on shared data structures and lots of poking randomly at blocks of RAM, a very natural way to think when you’re engrossed in the mechanics of an 8-bit CPU.
I had a better time writing a raycaster and later a path tracer, although by then I had learned to avoid dealing with the borrow checker…
If you’re going to write an emulator in this style, why even use an imperative language when something like Haskell is designed for this sort of thing?