func (p ErrorList) Err() error {
	if len(p) == 0 {
		return nil
	}
	return p
}

// PrintError is a utility function that prints a list of errors to w,
// one error per line, if the err parameter is an [ErrorList]. Otherwise
// it prints the err string.
func PrintError(w io.Writer, err error) {
	if list, ok := err.(ErrorList); ok {
		for _, e := range list {
			fmt.Fprintf(w, "%s\n", e)
		}

	var gofmtBuf strings.Builder
	if err := format.Node(&gofmtBuf, fset, n); err != nil {
		return "<" + err.Error() + ">"
	}
	return gofmtBuf.String()
}

func report(err error) {
	scanner.PrintError(os.Stderr, err)
	exitCode = 2
}

func walkDir(path string) {
	filepath.WalkDir(path, visitFile)
}

func visitFile(path string, f fs.DirEntry, err error) error {
	if err == nil && isGoFile(f) {

`

func usage() {
	fmt.Fprintln(os.Stderr, usageString)
	flag.PrintDefaults()
	os.Exit(2)
}

func report(err error) {
	if *panicOnError {
		panic(err)
	}
	scanner.PrintError(os.Stderr, err)
	if list, ok := err.(scanner.ErrorList); ok {
		errorCount += len(list)
		return
	}
	errorCount++
}

// parse may be called concurrently.