// All copyright is dedicated to the public domain with Creative Commons Zero 1.0 Universal.
// Anyone may do whatever they wish with this code.

package main

import "fmt"

type Visitor interface {
    Visit(e Element)
}

type Element interface {
    Accept(v Visitor)
}

type ConcreteElement1 struct {}

func (c ConcreteElement1) Accept(v Visitor) {
    v.Visit(c)
}

type ConcreteElement2 struct {}

func (c ConcreteElement2) Accept(v Visitor) {
    v.Visit(c)
}

type Visitor1 struct{}

func (v Visitor1) Visit(e Element) {
    switch e.(type) {
    case ConcreteElement1:
        fmt.Println("ConcreteElement1 in Visitor1")
    case ConcreteElement2:
        fmt.Println("ConcreteElement2 in Visitor1")
    }
}

func main() {
    var e Element = ConcreteElement1{}
    var v Visitor2 = Visitor2{}
    e.Accept(v)
}