Testando observáveis

observer_test.dart

void main(){
  final obs = Observable<String>();
  
  final items = List.generate(500,(i) => Observer<String>(obs));
  obs.setState("ib");
}

int fibonacci(int n) {
  if (n == 0 || n == 1) return n;
  return fibonacci(n - 1) + fibonacci(n - 2);
}



class Observable<T>{
   
   List<Observer<T>> observers = <Observer<T>>[];
   
   T data;

   void setState(T data){
     this.data = data;
     notifyObservers();
   }

   void notifyObservers(){
     final start = DateTime.now();
     print(start);
     final localObservers = List.from(observers);
     for (var observer in localObservers) {
       if(observers.contains(observer)){
          observer.update(data);
       }
     }
     
     final end = DateTime.now();
     print(end);
     
     print(start.difference(end).inMicroseconds);
   }
  
  void addObserver(Observer<T> observer){
    observers.add(observer);
  }
}

class Observer<T>{
    
  Observer(Observable observable){
    observable.addObserver(this);
  }
  

  void update(T data){
 fibonacci(20);
  }

}