switch n := x.(type) {
	default:
		error_(token.NoPos, "unexpected type %T in walk", x)
		panic("unexpected type")

	case *ast.IndexListExpr:
		f.walk(&n.X, ctxExpr, visit)
		f.walk(n.Indices, ctxExpr, visit)
	}
}

func funcTypeTypeParams(n *ast.FuncType) *ast.FieldList {
	return n.TypeParams
}

package main

import (
	"go/ast"
	"go/token"
)

func (f *File) walkUnexpected(x interface{}, context astContext, visit func(*File, interface{}, astContext)) {
	error_(token.NoPos, "unexpected type %T in walk", x)
	panic("unexpected type")
}

func funcTypeTypeParams(n *ast.FuncType) *ast.FieldList {
	return nil
}

func typeSpecTypeParams(n *ast.TypeSpec) *ast.FieldList {
	return nil

	dstRoot = filepath.Clean(dstRoot)
	if err := os.MkdirAll(dstRoot, 0777); err != nil {
		return err
	}

	srcRoot, err := filepath.Abs(srcRoot)
	if err != nil {
		return err
	}

	return filepath.Walk(srcRoot, func(srcPath string, info os.FileInfo, err error) error {
		if err != nil || srcPath == srcRoot {
			return err
		}

		suffix := strings.TrimPrefix(srcPath, srcRoot)

		if d.IsDir() {
			return nil
		}
		data, err := os.ReadFile(path)
		if err != nil {
			log.Fatal(err)
		}
		if strings.HasSuffix(path, ".zip") {
			log.Fatalf("unexpected file during walk: %s", path)
		}
		name := filepath.ToSlash(path)
		w, err := zw.CreateRaw(&zip.FileHeader{
			Name:               name,
			Method:             zip.Store,
			CompressedSize64:   uint64(len(data)),