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%META:TOPICINFO{author="IsaacGouy" date="1075391940" format="1.0" version="1.1"}%
%META:TOPICPARENT{name="CodeExamples"}%
/* Please try the NoviceExamples before the MultiMethodExamples
To compile:
nicec --sourcepath=.. -a benderfsm.jar benderfsm
To run:
java -jar benderfsm.jar
*/
private enum FsmState {Idle, On, Active}
class BenderFSM {
public void event(String e) = this.transition(state,e);
private FsmState state = Idle;
String last = "Unknown";
private void transition(FsmState s, String e){ last = "Unknown"; }
// Transition State Event Action
transition( Idle, "TurnOn" ){ state = On; last = "TurnOn"; }
transition( On, "TurnOff" ){ state = Idle; last = "TurnOff"; }
transition( On, "Activate" ){ state = Active; last = "Activate"; }
transition( Active, "Walk" ){ last = "Walk"; }
transition( Active, "Run" ){ last = "Run"; }
transition( Active, "Talk" ){ last = "Talk"; }
transition( Active, "Stop" ){ state = On; last = "Stop"; }
}
class SuperBenderFSM extends BenderFSM {
// Transition State Event Action
transition( Active, "Skip" ){ last = "Skip"; }
transition( Active, "Jump" ){ last = "Jump"; }
}
void main(String[] args){
let String[] events = [
"TurnOn", "Activate",
"Talk", "Run",
"Skip", "Jump", // Only SuperBenderFSM
"Stop", "TurnOff"
];
let bender = new BenderFSM();
let superB = new SuperBenderFSM();
for (e : events){
println("\n" + "Bender" +"\t"+"\t"+ "Super Bender");
println("State: " + bender.state + "\t" + superB.state);
bender.event(e); superB.event(e);
println("Event: " + bender.last + "\t" + superB.last);
println("State: " + bender.state + "\t" + superB.state);
}
}
/* Notes - language
Compare with Java and C++ at "Finite State Machine Tutorial"
http://www.generation5.org/content/2003/FSM_Tutorial.asp
private enum FsmState {Idle, On, Active}
Simple enumeration of possible Bender FSM states
// Transition State Event Action
transition( Idle, "TurnOn" ){ state = On; last = "TurnOn"; }
Multi methods allow a declarative encoding of FSM transitions as simple
message sends. In BenderFSM, Nice will dispatch the transition method by
BenderFSM instance, and by FsmState instance, and by String value, so we
simply provide an implementation of transition for each legal transition.
class SuperBenderFSM extends BenderFSM {
Simply subclass the Bender Finite State Machine to create a FSM with
additional transitions.
*/
-- IsaacGouy - 29 Jan 2004 |