引用另一个结构给出“未定义”

Question

I have some very simple golang code:

func main (){

      type config struct {
        interval     int    `mapstructure:"Interval"`
        statsdPrefix string `mapstructure:"statsd_prefix"`
        groups       []group
      }

      type group struct {
        group        string `mapstructure:"group"`
        targetPrefix string `mapstructure:"target_prefix"`
        targets      []target
      }
}

When I run this, I get the following:

undefined: group

What am I missing here?

Answer 1

Since you've defined the types in a function, the config type definition runs before there is a group type to reference. Reversing the order of your definitions works, although I had to remove the reference to target as you have not provided it's definition.

This works in the playgound https://play.golang.org/p/fzRCtCHqnH:

func main() {

    type group struct {
        group        string `mapstructure:"group"`
        targetPrefix string `mapstructure:"target_prefix"`
    }
    type config struct {
        interval     int    `mapstructure:"Interval"`
        statsdPrefix string `mapstructure:"statsd_prefix"`
        groups       []group
    }

}