Use a control flow enum, like https://doc.rust-lang.org/stable/std/ops/enum.ControlFlow.html, but perhaps with more variants:
- Ok / Continue (())
- Err / Halt ("")
- Break / Exit (in case the interpreter wants to exit? Probably works fine as a halt like it is now)
- Interrupt / Pause / Breakpoint / Step
- Wait / VBlank
Use a control flow enum, like https://doc.rust-lang.org/stable/std/ops/enum.ControlFlow.html, but perhaps with more variants: