Golang如何使用组合模式实现树状结构

type Component interface {
    GetName() string
    Print(depth int)
}

type File struct {
    name string
}
<p>func (f *File) GetName() string {
return f.name
}</p><p>func (f *File) Print(depth int) {
indent := strings.Repeat("  ", depth)
fmt.Printf("%s- %s\n", indent, f.name)
}

type Directory struct {
    name     string
    children []Component
}
<p>func (d *Directory) Add(child Component) {
d.children = append(d.children, child)
}</p><p>func (d *Directory) GetName() string {
return d.name
}</p><p>func (d *Directory) Print(depth int) {
indent := strings.Repeat("  ", depth)
fmt.Printf("%s+ %s\n", indent, d.name)
for _, child := range d.children {
child.Print(depth + 1)
}
}

root := &Directory{name: "root"}
docs := &Directory{name: "docs"}
pic := &Directory{name: "pics"}
<p>file1 := &File{name: "readme.txt"}
file2 := &File{name: "photo.jpg"}</p><p>docs.Add(file1)
pic.Add(file2)
root.Add(docs)
root.Add(pic)</p><p>root.Print(0)

+ root
  + docs
    - readme.txt
  + pics
    - photo.jpg