Event-driven finite-state machine

A finite state machine (FSM) is event driven if any incoming input has to be consumed immediately, i.e. the FSM has to perform a transition or input action otherwise the input disappears. In contrast to the virtual finite state machine (VFSM) technology, the application of event driven FSM in complex systems leads to the state explosion problem, as each truly required state path must be repeated for all possible input values. Event driven FSM is implemented with a state transition table and is mainly used for parser applications.