Add state machine example

examples/statemachine/statemachine.v

@@ -0,0 +1,33 @@
+import datatypes.fsm
+
+struct MyReceiver {
+mut:
+	data []string
+}
+
+fn main() {
+	mut receiver := &MyReceiver{}
+	mut s := fsm.new()
+	s.add_state('A', on_state_entry, on_state_run, on_state_exit)
+	s.add_state('B', on_state_entry, on_state_run, on_state_exit)
+	s.add_transition('A', 'B', condition_transition)
+	s.run(receiver)
+	s.run(receiver)
+	s.run(receiver)
+}
+
+fn on_state_entry(mut receiver MyReceiver) {
+	println('on_state_entry')
+}
+
+fn on_state_run(mut receiver MyReceiver) {
+	println('on_state_run')
+}
+
+fn on_state_exit(mut receiver MyReceiver) {
+	println('on_state_exit')
+}
+
+fn condition_transition(receiver &MyReceiver) bool {
+	return true
+}