f.Comments = ast1.Comments
	f.AST = ast2
}

// Like ast.CommentGroup's Text method but preserves
// leading blank lines, so that line numbers line up.
func commentText(g *ast.CommentGroup) string {
	pieces := make([]string, 0, len(g.List))
	for _, com := range g.List {
		c := com.Text
		// Remove comment markers.
		// The parser has given us exactly the comment text.
		switch c[1] {

	if err != nil {
		log.Fatalf("unexpected api file: %v", name)
	}
	return n >= 19 // started tracking approvals in Go 1.19
}

func (w *Walker) collectDeprecated() {
	isDeprecated := func(doc *ast.CommentGroup) bool {
		if doc != nil {
			for _, c := range doc.List {
				if strings.HasPrefix(c.Text, "// Deprecated:") {
					return true
				}
			}
		}
		return false
	}

pkg go/ast, func NewCommentMap(*token.FileSet, Node, []*CommentGroup) CommentMap
pkg go/ast, method (CommentMap) Comments() []*CommentGroup
pkg go/ast, method (CommentMap) Filter(Node) CommentMap
pkg go/ast, method (CommentMap) String() string
pkg go/ast, method (CommentMap) Update(Node, Node) Node
pkg go/ast, type ChanType struct, Arrow token.Pos
pkg go/ast, type CommentMap map[Node][]*CommentGroup
pkg go/build, const AllowBinary = 2