1 /*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
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_INFO_NOVEMBER_22_2008_1132AM)
8 #define BOOST_SPIRIT_INFO_NOVEMBER_22_2008_1132AM
14 #include <boost/variant/variant.hpp>
15 #include <boost/variant/recursive_variant.hpp>
16 #include <boost/variant/apply_visitor.hpp>
17 #include <boost/foreach.hpp>
18 #include <boost/spirit/home/support/utf8.hpp>
23 namespace boost { namespace spirit
25 // info provides information about a component. Each component
26 // has a what member function that returns an info object.
27 // strings in the info object are assumed to be encoded as UTF8
37 , recursive_wrapper<info>
38 , recursive_wrapper<std::pair<info, info> >
43 explicit info(utf8_string const& tag)
44 : tag(tag), value(nil()) {}
47 info(utf8_string const& tag, T const& value)
48 : tag(tag), value(value) {}
50 info(utf8_string const& tag, char value)
51 : tag(tag), value(utf8_string(1, value)) {}
53 info(utf8_string const& tag, wchar_t value)
54 : tag(tag), value(to_utf8(value)) {}
56 info(utf8_string const& tag, ucs4_char value)
57 : tag(tag), value(to_utf8(value)) {}
59 template <typename Char>
60 info(utf8_string const& tag, Char const* str)
61 : tag(tag), value(to_utf8(str)) {}
63 template <typename Char, typename Traits, typename Allocator>
64 info(utf8_string const& tag
65 , std::basic_string<Char, Traits, Allocator> const& str)
66 : tag(tag), value(to_utf8(str)) {}
72 template <typename Callback>
73 struct basic_info_walker
75 typedef void result_type;
76 typedef basic_info_walker<Callback> this_type;
78 basic_info_walker(Callback& callback, utf8_string const& tag, int depth)
79 : callback(callback), tag(tag), depth(depth) {}
81 void operator()(info::nil) const
83 callback.element(tag, "", depth);
86 void operator()(utf8_string const& str) const
88 callback.element(tag, str, depth);
91 void operator()(info const& what) const
94 this_type(callback, what.tag, depth+1), what.value);
97 void operator()(std::pair<info, info> const& pair) const
99 callback.element(tag, "", depth);
100 boost::apply_visitor(
101 this_type(callback, pair.first.tag, depth+1), pair.first.value);
102 boost::apply_visitor(
103 this_type(callback, pair.second.tag, depth+1), pair.second.value);
106 void operator()(std::list<info> const& l) const
108 callback.element(tag, "", depth);
109 BOOST_FOREACH(info const& what, l)
111 boost::apply_visitor(
112 this_type(callback, what.tag, depth+1), what.value);
117 utf8_string const& tag;
121 // silence MSVC warning C4512: assignment operator could not be generated
122 basic_info_walker& operator= (basic_info_walker const&);
125 // bare-bones print support
126 template <typename Out>
127 struct simple_printer
129 typedef utf8_string string;
131 simple_printer(Out& out)
134 void element(string const& tag, string const& value, int /*depth*/) const
137 out << '<' << tag << '>';
139 out << '"' << value << '"';
145 // silence MSVC warning C4512: assignment operator could not be generated
146 simple_printer& operator= (simple_printer const&);
149 template <typename Out>
150 Out& operator<<(Out& out, info const& what)
152 simple_printer<Out> pr(out);
153 basic_info_walker<simple_printer<Out> > walker(pr, what.tag, 0);
154 boost::apply_visitor(walker, what.value);