Mealy Type State Models
There are fundamentally two formulations of state machines.
- The Moore type machine has its action performed upon entry into the state.
- The Mealy type machine has its action performed upon exiting from the state.
The Detailed RulesIt's important to enumerate the exact rules of state machines that we intend to support:
- The state model consists of a set of states that have relatively arbitrary names. Each state is associated with a body of Tcl code that is executed when the state is entered. A state may accept parameters.
- The state model responds to a set of events that also have relatively arbitrary names. Events may also carry parameters.
- The state model implements a set of transitions where an event is dispatched to a state machine causing a transition to a new state and the execution of the code associated with the state.
- A transition can be ignored by a state.
- A transition can be deemed a logical impossibility (i.e. it can't happen) and this is considered an error.
- Any event that causes a transition into a state must carry the same parameters that the state accepts.