go文档模式，编译出错，各位道友帮忙看看

```go package config import "strings" type doc struct { value string sub map[string]doc } var root = new(doc) func Add(key string, value string) { keys := strings.Split(key, ".") var target = root for index, subkey := range keys { if target.sub == nil { target.sub = make(map[string]doc) target.sub[subkey] = doc{} } if index == len(keys)-1 { target.sub[subkey].value = value } else { target = target.sub[subkey] } } } func Get(key string) string { keys := strings.Split(key, ".") target := root for index, subkey := range keys { target = target.sub[subkey] if index == len(keys)-1 { return target.value } } return "" } ```


你这主题正文啥也不放，全放评论…… 编译错误信息也不给！