func (s *byteScanner) error(pos token.Position, msg string) {
s.ErrorCount++
if !s.Quiet {
fmt.Fprintf(os.Stderr, "robotstxt from %s: %s\n", pos.String(), msg)
}
}
func MutationID(pos token.Position) string {
pos.Filename = filepath.Base(pos.Filename)
return pos.String()
}