StateMachine
Implement a program that permits definition, creation and execution of finite state machine.
A state machine definition has the following Finite set of states One or more initial states One or more terminal states One or more events State transitions for events (explained in detail below)
Here is an example of a cash counting state machine. The machine will allow a purchase if and only the user deposits 4 rupees.Note that the lines starting with “//” are comments for your understanding
//states 0S 1S 2S 3S 4S CANCELLED COMPLETED
//initial state 0S
//terminal states CANCELLED COMPLETED
//events 1R 2R CANCEL BUY
// state transitions
(0S, 1R) 1S (0S, 2R) 2S (1S, 1R) 2S (1S, 2R) 3S (2S, 1R) 3S (2S, 2R) 4S (3S, 1R) 4S (*, CANCEL) CANCELLED (4S, COMPLETE) COMPLETED
The above input results in a state machine as follows
The next set of inputs/outputs show the creation and manipulation of a state machine i.e. an instance of the previously defined state machine is created and manipulated. Here’s a sample interaction. Lines starting with ‘>’ are inputs to the program, while lines starting with ‘<’ are outputs from the program
0S <0S 1R <1S 2R <3S 1R <4S BUY