实现装饰器模式示例，添加相关类和方法，增强代码可读性

go/decorator/main.go

@@ -0,0 +1,66 @@
+package main
+
+import "fmt"
+
+/*
+实例
+汤宝宝家有一台咖啡机，他会自动给美式咖啡加奶和糖...
+*/
+
+type Drink interface {
+	GetPrice() float64
+	cost()
+}
+
+type Coffee struct {
+	name  string
+	Price float64
+}
+
+func (c *Coffee) GetPrice() float64 {
+	return c.Price
+}
+
+func (c *Coffee) cost() {
+	fmt.Printf("一杯%s咖啡，价格%.2f元。\n", c.name, c.Price)
+}
+
+type Maker struct {
+	wrappedDrink Drink
+	milkPrice    float64
+	sugarPrice   float64
+}
+
+func (m *Maker) GetPrice() float64 {
+	return m.wrappedDrink.GetPrice()
+}
+
+func (m *Maker) cost() {
+	m.wrappedDrink.cost()
+	fmt.Printf("加了奶和糖，总价%.2f元。\n",
+		m.wrappedDrink.GetPrice()+m.milkPrice+m.sugarPrice)
+}
+
+func main() {
+	fmt.Println("============= 装饰器模式 =============")
+
+	var coffee, newCoffee Drink
+
+	fmt.Println("自己泡杯咖啡")
+	coffee = &Coffee{
+		name:  "美式",
+		Price: 10.0,
+	}
+	coffee.cost()
+
+	fmt.Println("\n用咖啡机泡杯咖啡")
+	newCoffee = &Maker{
+		wrappedDrink: coffee,
+		milkPrice:    1.0,
+		sugarPrice:   1.0,
+	}
+	newCoffee.cost()
+
+	fmt.Println()
+	fmt.Println("=========== 装饰器模式结束 ===========")
+}