enum Maybe<T> {
	Nothing;
	Just(v : T);
}

class QueryIterator<T> {
	var result : Dynamic;
	var nextValue : Maybe<T>;
	public function new(result) {
		this.result= result;
		/* We fetch the first row , so we can answer hasNext */
		fetch();
	}

	private function fetch() {
		var next : Dynamic = untyped __call__('db_fetch', this.result);
		nextValue = if(next) Just(next) else Nothing;
	}

	public function  hasNext() : Bool {
		return this.nextValue != Nothing;
	}

	public function next() : T {
		switch(this.nextValue) {
		case Nothing : throw 'Iterator exhausted';
		case Just(v) :  {
			this.fetch();
			return v;
		};
		}
	}
}