facade pattern

README.md

@@ -28,7 +28,7 @@ A curated collection of idiomatic design & application patterns for Go language.
 | [Bridge](/structural/bridge/main.go) | Decouples an interface from its implementation so that the two can vary independently | ✔ |
 | [Composite](/structural/composite/main.go) | Encapsulates and provides access to a number of different objects | ✔ |
 | [Decorator](/structural/decorator.md) | Adds behavior to an object, statically or dynamically | ✔ |
-| [Facade](/structural/facade.md) | Uses one type as an API to a number of others | ✘ |
+| [Facade](/structural/facade/main.go) | Uses one type as an API to a number of others | ✔ |
 | [Flyweight](/structural/flyweight.md) | Reuses existing instances of objects with similar/identical state to minimize resource usage | ✘ |
 | [Proxy](/structural/proxy.md) | Provides a surrogate for an object to control it's actions | ✔ |
 

structural/facade/main.go

@@ -0,0 +1,52 @@
+// 外观模式 facade pattern.
+// 为多个子模块提供一个统一的调用接口,子模块可以是同一接口的实现也可以不同.
+// 实际上编写程序的时候很多地方不知不觉的会使用了模式.
+// 这里以购买鸡蛋，牛奶，小麦粉为例，从代购处一次性购买三种而不需要分别访问三个商店
+package main
+
+type Shop interface {
+	Sell()
+}
+
+type EggShop struct {}
+
+func (EggShop)Sell(){
+	println("no more eggs left")
+}
+
+type MilkShop struct {}
+
+func (MilkShop)Sell(){
+	println("no more milk left")
+}
+
+type WheatFlourShop struct {}
+
+func (WheatFlourShop)Sell(){
+	println("no more wheat flour left")
+}
+
+type DealerFacade struct {
+	EgShop Shop
+	MkShop Shop
+	WfShop Shop
+}
+
+func (d DealerFacade)SellAll(){
+	d.EgShop.Sell()
+	d.MkShop.Sell()
+	d.WfShop.Sell()
+}
+
+func main(){
+	dealer := DealerFacade{
+		EggShop{},
+		MilkShop{},
+		WheatFlourShop{},
+	}
+	dealer.SellAll()
+}
+
+
+
+