code: func functions(args []string) {
  	files, err := ioutil.ReadDir("functions")
  	if err != nil {
  		return
  	}
  
  	for _, file := range files {
  		if !utils.ContainsString(args, file.Name()) {
  			fmt.Printf("%s ", file.Name())
  		}
  	}
  }
docs: // output (deduped) functions.