装饰者模式

装饰者模式

统一接口

package decorator

type decorator interface {
    getPrice() uint8
    getDesc() string
}

炒饭（被装饰者）

package decorator

type rice struct {
	price uint8
}

func NewRice(price uint8) *rice {
	return &rice{price: price}
}

func (r *rice) getPrice() uint8 {
	return r.price
}

func (r *rice) getDesc() string {
	return "白炒饭"
}

炒面（被装饰者）

package decorator

type noodles struct {
	price uint8
}

func NewNoodles(price uint8) *noodles {
	return &noodles{price: price}
}

func (n *noodles) getPrice() uint8 {
	return n.price
}

func (n *noodles) getDesc() string {
	return "素炒面"
}

鸡蛋（装饰者）

package decorator

type egg struct {
	decorator
	price uint8
}

func NewEgg(d decorator, price uint8) decorator {
	return &egg{
		decorator: d,
		price:     price,
	}
}

func (e *egg) getPrice() uint8 {
	return e.price + e.decorator.getPrice()
}

func (e *egg) getDesc() string {
	return e.decorator.getDesc() + "加蛋"
}

火腿肠

package decorator

type ham struct {
	decorator
	price uint8
}

func NewHam(d decorator, price uint8) decorator {
	return &ham{
		decorator: d,
		price:     price,
	}
}

func (h *ham) getPrice() uint8 {
	return h.price + h.decorator.getPrice()
}

func (h *ham) getDesc() string {
	return h.decorator.getDesc() + "加火腿肠"
}

测试文件

package decorator

func TestDecorator(t *testing.T) {
	r := NewRice(10)
	re := NewEgg(r, 2)
	reh := NewHam(re, 3)
	fmt.Println(reh.getPrice(), reh.getDesc())

	n := NewNoodles(8)
	ne := NewEgg(n, 2)
	nee := NewEgg(ne, 3)
	fmt.Println(nee.getPrice(), nee.getDesc())
}