simple_service_locator.dart

void main() {
  setupLocator();
  print(locator<String>());
}
final locator = Locator();
void setupLocator(){
  locator.registerSingleton<String>(()=>'Yello World');
 
  locator.registerSingleton<double>(()=>25.0);
}

typedef FactoryFunc<T> = T Function();

///Simple service locator
class Locator{
  factory Locator() => _instance;
  static final Locator _instance = Locator._internal();
  
  final Map<dynamic, dynamic> _items = {};
  Locator._internal();
  
  void registerSingleton<T extends Object>(FactoryFunc<T> factoryFunc){
    _items.putIfAbsent(T, factoryFunc);
  }
  
  T get<T>(){
    return _items[T];
  }
  
  T call<T>(){
    return _items[T];
  }
  
}