1. Automata Based Programming Margarita Spitšakova Institute of Cybernetics at Tallinn University of Technology 19.03.08

2. Outline Introduction Definition of FSM Usage of FSM FSM as programs Example Future work Conclusions Software, further reading

3. Introduction Master thesis: “Genetic Inference of Finite State Machines” Finite state machine is something abstract Why I need to generate FSMs?

4. Finite State Machines States, transitions, input and output alphabets, final state, initial state. Moore machine (output at state) Mealy machine (output at transition) Deterministic machine

5. Using FSM FSM as hardware model Text recognition (regular expressions) Text transformations Pushdown automata in parsers

6. FSM as program Event Controller = Finite State Machines Controlled object Event Controlled object

7. Example. Traffic Lights Red Green Yellow Blinking green Red + yellow

8. Model

9. Source code. Controlled object public class TrafficLight implements ControlledObject { public void red(StateMachineContext context) { System.out.println("Red"); } public void green(StateMachineContext context) { System.out.println("Green"); } public void yellow(StateMachineContext context) { System.out.println("Yellow"); } public void greenblink(StateMachineContext context) { System.out.println("Green Blinking"); } public void redyellow(StateMachineContext context) { System.out.println("red yellow"); }

10. FSM

11. Source code. Controller switch (s) { case green: switch (event) { case next tick: if (counter_x4 < 20) { make transition to state “blinking green”; return new StateMachineConfig("blinking green"); } if (counter_x4 >= 20) { make transition to final state; return new StateMachineConfig(" final state "); } … } Switch technology

12. Conclusions Modeling system Modeling=writing the code Step-by-step Easier to verify Good for modeling reactive systems

13. Future work Event Controller = Finite State Machine Controlled object Event Controlled object Can be generated

14. Software. Further reading Unimod. Eclipse plugin for designing object- oriented event-driven applications using automata-based programming adapted for UML. http://unimod.sourceforge.nethttp://unimod.sourceforge.net AutoFSM. http://autogen.sourceforge.nethttp://autogen.sourceforge.net Сайт по автоматному программированию http://is.ifmo.ru/http://is.ifmo.ru/