bridge pattern

README.md

@@ -25,7 +25,7 @@ A curated collection of idiomatic design & application patterns for Go language.
 
 | Pattern | Description | Status |
 |:-------:|:----------- |:------:|
-| [Bridge](/structural/bridge.md) | Decouples an interface from its implementation so that the two can vary independently | ✘ |
+| [Bridge](/structural/bridge/main.go) | Decouples an interface from its implementation so that the two can vary independently | ✔ |
 | [Composite](/structural/composite.md) | 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 | ✘ |

structural/bridge/main.go

@@ -0,0 +1,91 @@
+// 桥接模式 bridge pattern.
+// 桥接模式与策略模式有很多相似之处，原因在于他们都将行为交给了另一个接口实现，
+// 桥接解决的是A+M、B+N、A+N等这样的调用者和行为的组合问题，是将不匹配的接口相组合,使之能够被统一的调用,一旦组合运行时一般不会发生变化.
+// 策略模式则是为了动态的扩展，改变算法.本质上说桥接是结构模式策略是行为模式，侧重的分别是结构的组合和结构之间的通信
+package main
+
+// abstraction
+type VehicleAbstraction interface {
+	Run()
+	MaxSpeed() int
+}
+
+// refined abstraction
+type Truck struct {
+	Driver DriverImplementor
+	maxSpeed int
+}
+
+func (t Truck)Run(){
+	println("truck begin to move...")
+	t.Driver.Drive(t)
+}
+
+func (t Truck)MaxSpeed() int{
+	return t.maxSpeed
+}
+
+// refined abstraction
+type Car struct {
+	Driver DriverImplementor
+	maxSpeed int
+}
+
+func (c Car)Run(){
+	println("car begin to move...")
+	c.Driver.Drive(c)
+}
+
+func (c Car)MaxSpeed() int{
+	return c.maxSpeed
+}
+
+// implementor
+type DriverImplementor interface {
+	Drive(vi VehicleAbstraction)
+}
+
+// concrete implementor
+type RookieDriver struct {}
+
+func (RookieDriver) Drive(vi VehicleAbstraction) {
+	println("rookie driver -> speed" ,vi.MaxSpeed() >> 1 ,"km/h")
+}
+
+// concrete implementor
+type OldDriver struct {}
+
+func (OldDriver)Drive(vi VehicleAbstraction){
+	println("old driver -> speed" ,vi.MaxSpeed() ,"km/h")
+}
+
+func main(){
+	old := OldDriver{}
+	rk := RookieDriver{}
+	v1 := Truck{old ,60}
+	v2 := Car{old ,130}
+	v3 := Truck{rk ,60}
+	v4 := Car{rk ,130}
+	list := []VehicleAbstraction{v1 ,v2 ,v3 ,v4}
+	for _ ,v := range list{
+		v.Run()
+	}
+	/*
+	output:
+	truck begin to move...
+	old driver -> speed 60 km/h
+	car begin to move...
+	old driver -> speed 130 km/h
+	truck begin to move...
+	rookie driver -> speed 30 km/h
+	car begin to move...
+	rookie driver -> speed 65 km/h
+	 */
+
+}
+
+
+
+
+
+