Golang如何使用组合模式管理层次结构

type Component interface {
    Display(indent string)
}

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

func (f *File) Display(indent string) {
    println(indent + "? " + f.name)
}

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

func (f *Folder) Add(child Component) {
    f.children = append(f.children, child)
}

func (f *Folder) Display(indent string) {
    println(indent + "? " + f.name)
    for _, child := range f.children {
        child.Display(indent + "  ")
    }
}

func main() {
    root := &Folder{name: "root"}
    
    src := &Folder{name: "src"}
    src.Add(&File{name: "main.go"})
    src.Add(&File{name: "utils.go"})

    doc := &Folder{name: "docs"}
    doc.Add(&File{name: "api.md"})

    root.Add(src)
    root.Add(doc)
    root.Add(&File{name: "README.md"})

    root.Display("")
}

? root
  ? src
    ? main.go
    ? utils.go
  ? docs
    ? api.md
  ? README.md