func crawl(url string) []string { fmt.Println(url) list, err := links.Extract(url) if err != nil { log.Print(err) } return list }
func crawl(url string) []string { fmt.Println(url) tokens <- struct{}{} // acquire a token list, err := links.Extract(url) <-tokens // release the token if err != nil { log.Print(err) } return list }