81 lines
1.4 KiB
Go
81 lines
1.4 KiB
Go
package main
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import "fmt"
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/*
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实例：
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汤宝宝坚信搭积木是人类的未来，因此开办了一家积木厂。
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*/
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// 抽象Node接口 Shape
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type Shape interface {
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Accept(visitor Visitor)
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ClaimShape()
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}
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type Circle struct{}
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func (c *Circle) Accept(visitor Visitor) {
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visitor.VisitCircle(c)
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}
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func (c *Circle) ClaimShape() {
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fmt.Println("I am a Circle")
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}
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type Square struct{}
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func (s *Square) Accept(visitor Visitor) {
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visitor.VisitSquare(s)
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}
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func (s *Square) ClaimShape() {
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fmt.Println("I am a Square")
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}
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type Triangle struct{}
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func (t *Triangle) Accept(visitor Visitor) {
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visitor.VisitTriangle(t)
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}
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func (t *Triangle) ClaimShape() {
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fmt.Println("I am a Triangle")
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}
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// 抽象NodeVisitor接口 Visitor
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type Visitor interface {
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VisitCircle(c *Circle)
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VisitSquare(s *Square)
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VisitTriangle(t *Triangle)
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}
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type ShapeVisitor struct{}
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func (sv *ShapeVisitor) VisitCircle(c *Circle) {
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fmt.Print("Visiting Circle: ")
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c.ClaimShape()
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}
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func (sv *ShapeVisitor) VisitSquare(s *Square) {
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fmt.Print("Visiting Square: ")
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s.ClaimShape()
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}
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func (sv *ShapeVisitor) VisitTriangle(t *Triangle) {
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fmt.Print("Visiting Triangle: ")
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t.ClaimShape()
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}
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func main() {
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fmt.Println("========== 访问者模式 ==========")
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shapes := []Shape{&Circle{}, &Square{}, &Triangle{}}
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visitor := &ShapeVisitor{}
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for _, shape := range shapes {
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shape.Accept(visitor)
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}
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fmt.Println()
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fmt.Println("======== 访问者模式结束 ========")
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}
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