// bug, this test failed with a runtime panic.
	src := "package p\ntype T struct {\n\tF int `json:\"f\"` // a field\n}\n"

	fset := token.NewFileSet()
	f, err := parser.ParseFile(fset, "", src, 0)
	if err != nil {
		panic(err)
	}

	for n := range ast.Preorder(f) {
		if id, ok := n.(*ast.Ident); ok && id.Name == "F" {
			break
		}
	}

	var buf strings.Builder
	for _, g := range list {
		buf.WriteString(g.Text())
	}
	return buf.String()
}

func TestCommentMap(t *testing.T) {
	fset := token.NewFileSet()
	f, err := parser.ParseFile(fset, "", src, parser.ParseComments)
	if err != nil {
		t.Fatal(err)
	}
	cmap := NewCommentMap(fset, f, f.Comments)

	// very correct association of comments
	for n, list := range cmap {

	for _, src := range []string{
		`package p; func _()`,
		`package p; func _() {`,
		`package p; func _() { _ = 0`,
		`package p; func _() { _ = 0 }`,
	} {
		fset := token.NewFileSet()
		f, _ := parser.ParseFile(fset, "", src, parser.AllErrors)
		if f == nil {
			panic("invalid test setup: parser didn't return an AST")
		}

		// find corresponding token.File
		var tf *token.File
		fset.Iterate(func(f *token.File) bool {

	skip   = flag.String("skip", "", "files matching this regular expression are skipped by TestStdLib")
)

func TestParse(t *testing.T) {
	ParseFile(*src_, func(err error) { t.Error(err) }, nil, 0)
}

func TestVerify(t *testing.T) {
	ast, err := ParseFile(*src_, func(err error) { t.Error(err) }, nil, 0)
	if err != nil {
		return // error already reported
	}
	verifyPrint(t, *src_, ast)
}

	less []string
	op   string // Either "<" or "!<"
	def  []string
}

type syntaxError string

func (e syntaxError) Error() string {
	return string(e)
}

// parseRules parses the rules of a DAG.
func parseRules(rules string) (out []rule, err error) {
	defer func() {
		e := recover()
		switch e := e.(type) {
		case nil:
			return
		case syntaxError:
			err = e
		default:
			panic(e)

func initialize() {
	const filename = "testdata/parser.go"

	src, err := os.ReadFile(filename)
	if err != nil {
		log.Fatalf("%s", err)
	}

	file, err := parser.ParseFile(fset, filename, src, parser.ParseComments)
	if err != nil {
		log.Fatalf("%s", err)
	}

	var buf bytes.Buffer
	testprint(&buf, file)
	if !bytes.Equal(buf.Bytes(), src) {

				}
			}
		})
	})
}

func walkCodes(t *testing.T, f func(string, int, *ast.ValueSpec)) {
	t.Helper()
	fset := token.NewFileSet()
	file, err := parser.ParseFile(fset, "codes.go", nil, parser.ParseComments)
	if err != nil {
		t.Fatal(err)
	}
	conf := Config{Importer: importer.Default()}
	info := &Info{
		Types: make(map[ast.Expr]TypeAndValue),

	files, _ := filepath.Glob("testdata/*.txt")
	if len(files) == 0 {
		t.Fatalf("no testdata")
	}

	for _, file := range files {
		t.Run(filepath.Base(file), func(t *testing.T) {
			a, err := txtar.ParseFile(file)
			if err != nil {
				t.Fatal(err)
			}
			if len(a.Files) != 3 || a.Files[2].Name != "diff" {
				t.Fatalf("%s: want three files, third named \"diff\"", file)
			}

			fset := token.NewFileSet()
			astFile, err := parser.ParseFile(fset, filename, nil, parser.ParseComments)
			if err != nil {
				t.Fatal(err)
			}
			goldenFilename := strings.TrimSuffix(filename, ".go") + ".golden"
			archive, err := txtar.ParseFile(goldenFilename)
			if err != nil {
				t.Fatal(err)
			}
			golden := map[string]string{}

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package route

import (
	"syscall"
	"unsafe"
)

func (typ RIBType) parseable() bool {
	switch typ {
	case syscall.NET_RT_STATS, syscall.NET_RT_TABLE:
		return false
	default:
		return true
	}
}

// RouteMetrics represents route metrics.
type RouteMetrics struct {