This sounds more like a product than a composition but I’m not sure. I think the parent is hinting to use established compcomp language. Sipser is a good read for this
I'm not sure if this is a new form of state machine.
If you look at the code here you'll see that the select state uses some functions from the parameter state.
https://github.com/sdzx-1/ray-game/blob/master/src/select.zi...
So you can see that the select state itself is incomplete, and the parameter state completes it.
It doesn't seem to be any of the 3 described above.
Perhaps it is reasonable to call it semantic composition.
Higher order finite state machines that require other states as parameters to work.
https://github.com/sdzx-1/ray-game/blob/master/src/select.zi...
The select, inside, and hover states here are all high-level states, and all require two state parameters. And these three states form a small state machine for handling mouse interactive selection.
Can I think of this way of using higher-order state machines as a kind of composition? A semantic composition.