go/src/cmd/compile/internal/syntax/walk.go

// Inspect traverses an AST in pre-order: it starts by calling f(root);
// root must not be nil. If f returns true, Inspect invokes f recursively
// for each of the non-nil children of root, followed by a call of f(nil).
//
// See Walk for caveats about shared nodes.
func Inspect(root Node, f func(Node) bool) { … }

type inspector …

func (v inspector) Visit(node Node) Visitor { … }

// Walk traverses an AST in pre-order: It starts by calling
// v.Visit(node); node must not be nil. If the visitor w returned by
// v.Visit(node) is not nil, Walk is invoked recursively with visitor
// w for each of the non-nil children of node, followed by a call of
// w.Visit(nil).
//
// Some nodes may be shared among multiple parent nodes (e.g., types in
// field lists such as type T in "a, b, c T"). Such shared nodes are
// walked multiple times.
// TODO(gri) Revisit this design. It may make sense to walk those nodes
// only once. A place where this matters is types2.TestResolveIdents.
func Walk(root Node, v Visitor) { … }

type Visitor …

type walker …

func (w walker) node(n Node) { … }

func (w walker) declList(list []Decl) { … }

func (w walker) exprList(list []Expr) { … }

func (w walker) stmtList(list []Stmt) { … }

func (w walker) nameList(list []*Name) { … }

func (w walker) fieldList(list []*Field) { … }