DISCLAIMER: These notes are from the defunct k8 project which precedes SquirrelJME. The notes for SquirrelJME start on 2016/02/26! The k8 project was effectively a Java SE 8 operating system and as such all of the notes are in the context of that scope. That project is no longer my goal as SquirrelJME is the spiritual successor to it.
Just putting down that real life busy.
Stack states can be done easily by just checking the list, first I would check pops for any match, if there are none then the operation has a stack state which it cannot operate on.
The state managing the stack stuff should make things easier to implement during translation to register based form.