1/*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
3
4 Distributed under the Boost Software License, Version 1.0. (See accompanying
5 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6=============================================================================*/
7#if !defined(BOOST_SPIRIT_CALC8_ANNOTATION_HPP)
8#define BOOST_SPIRIT_CALC8_ANNOTATION_HPP
9
10#include <map>
11#include <boost/variant/apply_visitor.hpp>
12#include <boost/type_traits/is_base_of.hpp>
13#include <boost/mpl/bool.hpp>
14#include "ast.hpp"
15
16namespace client
17{
18 ///////////////////////////////////////////////////////////////////////////////
19 // The annotation handler links the AST to a map of iterator positions
20 // for the purpose of subsequent semantic error handling when the
21 // program is being compiled.
22 ///////////////////////////////////////////////////////////////////////////////
23 template <typename Iterator>
24 struct annotation
25 {
26 template <typename, typename>
27 struct result { typedef void type; };
28
29 std::vector<Iterator>& iters;
30 annotation(std::vector<Iterator>& iters)
31 : iters(iters) {}
32
33 struct set_id
34 {
35 typedef void result_type;
36
37 int id;
38 set_id(int id) : id(id) {}
39
40 template <typename T>
41 void operator()(T& x) const
42 {
43 this->dispatch(x, boost::is_base_of<ast::tagged, T>());
44 }
45
46 // This will catch all nodes except those inheriting from ast::tagged
47 template <typename T>
48 void dispatch(T& x, boost::mpl::false_) const
49 {
50 // (no-op) no need for tags
51 }
52
53 // This will catch all nodes inheriting from ast::tagged
54 template <typename T>
55 void dispatch(T& x, boost::mpl::true_) const
56 {
57 x.id = id;
58 }
59 };
60
61 void operator()(ast::operand& ast, Iterator pos) const
62 {
63 int id = iters.size();
64 iters.push_back(pos);
65 boost::apply_visitor(set_id(id), ast);
66 }
67
68 void operator()(ast::assignment& ast, Iterator pos) const
69 {
70 int id = iters.size();
71 iters.push_back(pos);
72 ast.lhs.id = id;
73 }
74 };
75}
76
77#endif
78
79

source code of boost/libs/spirit/example/qi/compiler_tutorial/calc8/annotation.hpp