// 팩토리
const Operator = class {
    static factory(v){
        if (v instanceof Object) {
            if (!Array.isArray(v)) v = Object.values(v);
            return new ArrayOp(v.map(v => Operator.factory(v)));
        }else return typeof v === "string" ? new StringOp(v) : new PrimaOp(v);
    }
    constructor(v) {this.v = v;}
    operation(f) {throw 'override';}
};

// 컴포지트
const StringOp = class extends Operator{
     constructor(v) {super(v);}
     operation(f){for (const a of this.v) f(a)}
 }

const PrimaOp = class extends Operator{
    constructor(v) {super(v);}
    operation(f){f(this.v);}
}

const ArrayOp = class extends Operator {
    constructor(v) {super(v);}
    operation(f){for (const v of this.v) v.operation(f);}
}

Operator.factory([1,2,3, {a:'abc', b:5}, 6, 7]).operation(console.log);

// 1
// 2
// 3
// a
// b
// c
// 5
// 6
// 7