1 | // (C) Copyright Jeremy Siek 1999. |
2 | // Distributed under the Boost Software License, Version 1.0. (See |
3 | // accompanying file LICENSE_1_0.txt or copy at |
4 | // http://www.boost.org/LICENSE_1_0.txt) |
5 | |
6 | #ifndef BOOST_TREE_STRUCTURE_HPP |
7 | #define BOOST_TREE_STRUCTURE_HPP |
8 | |
9 | namespace boost { |
10 | |
11 | template <class T> |
12 | struct tree_traits { |
13 | typedef typename T::node_descriptor node_descriptor; |
14 | typedef typename T::children_iterator children_iterator; |
15 | }; |
16 | |
17 | |
18 | template <class Tree, class TreeVisitor> |
19 | void traverse_tree(typename tree_traits<Tree>::node_descriptor v, |
20 | Tree& t, TreeVisitor visitor) |
21 | { |
22 | visitor.preorder(v, t); |
23 | typename tree_traits<Tree>::children_iterator i, end; |
24 | boost::tie(i, end) = children(v, t); |
25 | if (i != end) { |
26 | traverse_tree(*i++, t, visitor); |
27 | visitor.inorder(v, t); |
28 | while (i != end) |
29 | traverse_tree(*i++, t, visitor); |
30 | } else |
31 | visitor.inorder(v, t); |
32 | visitor.postorder(v, t); |
33 | } |
34 | |
35 | struct null_tree_visitor { |
36 | template <typename Node, typename Tree> void preorder(Node, Tree&) { } |
37 | template <typename Node, typename Tree> void inorder(Node, Tree&) { } |
38 | template <typename Node, typename Tree> void postorder(Node, Tree&) { } |
39 | }; |
40 | |
41 | } /* namespace boost */ |
42 | |
43 | #endif /* BOOST_TREE_STRUCTURE_HPP */ |
44 | |