1 /*=============================================================================
2 Copyright (c) 2003 Sam Nabialek
3 Copyright (c) 2001-2010 Joel de Guzman
4
5 Distributed under the Boost Software License, Version 1.0. (See accompanying
6 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7 =============================================================================*/
8 ///////////////////////////////////////////////////////////////////////////////
9 //
10 // The Nabialek trick.
11 //
12 // [ Sam Nabialek; Somewhere, sometime in 2003... ] spirit1
13 // [ JDG November 17, 2009 ] spirit2
14 // [ JDG January 10, 2010 ] Updated to use rule pointers
15 // for efficiency.
16 //
17 ///////////////////////////////////////////////////////////////////////////////
18
19 #include <boost/config/warning_disable.hpp>
20 #include <boost/spirit/include/qi.hpp>
21 #include <boost/spirit/include/phoenix_operator.hpp>
22 #include <iostream>
23 #include <string>
24
25 namespace client
26 {
27 namespace qi = boost::spirit::qi;
28 namespace ascii = boost::spirit::ascii;
29
30 ///////////////////////////////////////////////////////////////////////////////
31 // Our nabialek_trick grammar
32 ///////////////////////////////////////////////////////////////////////////////
33 template <typename Iterator>
34 struct nabialek_trick : qi::grammar<
35 Iterator, ascii::space_type, qi::locals<qi::rule<Iterator, ascii::space_type>*> >
36 {
nabialek_trickclient::nabialek_trick37 nabialek_trick() : nabialek_trick::base_type(start)
38 {
39 using ascii::alnum;
40 using qi::lexeme;
41 using qi::lazy;
42 using qi::_a;
43 using qi::_1;
44
45 id = lexeme[*(ascii::alnum | '_')];
46 one = id;
47 two = id >> ',' >> id;
48
49 keyword.add
50 ("one", &one)
51 ("two", &two)
52 ;
53
54 start = *(keyword[_a = _1] >> lazy(*_a));
55 }
56
57 qi::rule<Iterator, ascii::space_type> id, one, two;
58 qi::rule<Iterator, ascii::space_type, qi::locals<qi::rule<Iterator, ascii::space_type>*> > start;
59 qi::symbols<char, qi::rule<Iterator, ascii::space_type>*> keyword;
60 };
61 }
62
63 ///////////////////////////////////////////////////////////////////////////////
64 // Main program
65 ///////////////////////////////////////////////////////////////////////////////
66 int
main()67 main()
68 {
69 using boost::spirit::ascii::space;
70 typedef std::string::const_iterator iterator_type;
71 typedef client::nabialek_trick<iterator_type> nabialek_trick;
72
73 nabialek_trick g; // Our grammar
74
75 std::string str = "one only\none again\ntwo first,second";
76 std::string::const_iterator iter = str.begin();
77 std::string::const_iterator end = str.end();
78 bool r = phrase_parse(iter, end, g, space);
79
80 if (r && iter == end)
81 {
82 std::cout << "-------------------------\n";
83 std::cout << "Parsing succeeded\n";
84 std::cout << "-------------------------\n";
85 }
86 else
87 {
88 std::string rest(iter, end);
89 std::cout << "-------------------------\n";
90 std::cout << "Parsing failed\n";
91 std::cout << "stopped at: \": " << rest << "\"\n";
92 std::cout << "-------------------------\n";
93 }
94
95 return 0;
96 }
97
98
99