It would be nice to group all the functions that operate on a piece of state together in the same place. It would also be nice to prevent functions that are no

It would be nice to group all the functions that operate on a piece of state together in the same place. It would also be nice to prevent functions that are not in this group to make changes to that part of the state. Then you could prefix all those functions with a name, so it's clear what's their scope. Finally, in some cases it would be great if you could create multiple independent "instances" of the state, so you could manage more than one at a time without risking conflicts between the various copies.