// 1번
function makeFibonacci(n){
    let first = 0, second = 1, result;
    return () => {
        result = first + second;
        if (result > n) return null;
        first = second;
        second = result;
        return result;
    }
}

const fun = makeFibonacci(8);

// 2번
function makeFibonacci(n){
    let first = 0, second = 1, result, done = false;
    return {
        next(){
            if (done === true) return null;
            result = first + second;
            first = second;
            second = result; 
            if (result >= n) done = true;
            console.log({value: result, done: done});
            this.next();
        }
    }; 
}

const fun = makeFibonacci(1000);