What is state explosion?
The main problem that’s stopping widespread usage of state machines is the fact that beyond very simple examples, state machines often end up with numerous states, a lot of them with identical transitions. statecharts solve this state explosion problem.
Similar to nested positive if statements, state explosions represent combinatorially complex growth of states. This can also be seen with nested product-types.
How do statecharts solve this problem?
Parallel states
Separating nested finite states into individual states that can be progressed with the same or different events:
Hierarchical states
Reorganizing nested finite states into a hierarchy, such that the finite state of a child state machine is dependent on the transition between the parent and child machines:
Guards (conditions)
Guards here serve as a pre-condition to a transition, which essentially prevents a transition from occurring based on a condition:
