Golang组合模式树形结构应用实例

package main

import "fmt"

// Component 接口：统一处理文件和目录
type Component interface {
    Print(indent string)
    Add(c Component)
}

// File 叶子节点
type File struct {
    name string
}

func (f *File) Print(indent string) {
    fmt.Println(indent + f.name)
}

func (f *File) Add(c Component) {
    fmt.Println("文件不能添加子元素")
}

// Directory 容器节点
type Directory struct {
    name     string
    children []Component
}

func (d *Directory) Print(indent string) {
    fmt.Println(indent + d.name + "/")
    for _, child := range d.children {
        child.Print(indent + "  ")
    }
}

func (d *Directory) Add(c Component) {
    d.children = append(d.children, c)
}

func main() {
    root := &Directory{name: "root"}
    src := &Directory{name: "src"}
    bin := &Directory{name: "bin"}

    root.Add(src)
    root.Add(bin)
    src.Add(&File{name: "main.go"})
    bin.Add(&File{name: "app.exe"})

    root.Print("")
}

root/
  src/
    main.go
  bin/
    app.exe