1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
|
/*=============================================================================
Copyright (c) 2003 Sam Nabialek
Copyright (c) 2001-2010 Joel de Guzman
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
///////////////////////////////////////////////////////////////////////////////
//
// The Nabialek trick.
//
// [ Sam Nabialek; Somewhere, sometime in 2003... ] spirit1
// [ JDG November 17, 2009 ] spirit2
// [ JDG January 10, 2010 ] Updated to use rule pointers
// for efficiency.
//
///////////////////////////////////////////////////////////////////////////////
#include <boost/config/warning_disable.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix_operator.hpp>
#include <iostream>
#include <string>
namespace client
{
namespace qi = boost::spirit::qi;
namespace ascii = boost::spirit::ascii;
///////////////////////////////////////////////////////////////////////////////
// Our nabialek_trick grammar
///////////////////////////////////////////////////////////////////////////////
template <typename Iterator>
struct nabialek_trick : qi::grammar<
Iterator, ascii::space_type, qi::locals<qi::rule<Iterator, ascii::space_type>*> >
{
nabialek_trick() : nabialek_trick::base_type(start)
{
using ascii::alnum;
using qi::lexeme;
using qi::lazy;
using qi::_a;
using qi::_1;
id = lexeme[*(ascii::alnum | '_')];
one = id;
two = id >> ',' >> id;
keyword.add
("one", &one)
("two", &two)
;
start = *(keyword[_a = _1] >> lazy(*_a));
}
qi::rule<Iterator, ascii::space_type> id, one, two;
qi::rule<Iterator, ascii::space_type, qi::locals<qi::rule<Iterator, ascii::space_type>*> > start;
qi::symbols<char, qi::rule<Iterator, ascii::space_type>*> keyword;
};
}
///////////////////////////////////////////////////////////////////////////////
// Main program
///////////////////////////////////////////////////////////////////////////////
int
main()
{
using boost::spirit::ascii::space;
typedef std::string::const_iterator iterator_type;
typedef client::nabialek_trick<iterator_type> nabialek_trick;
nabialek_trick g; // Our grammar
std::string str = "one only\none again\ntwo first,second";
std::string::const_iterator iter = str.begin();
std::string::const_iterator end = str.end();
bool r = phrase_parse(iter, end, g, space);
if (r && iter == end)
{
std::cout << "-------------------------\n";
std::cout << "Parsing succeeded\n";
std::cout << "-------------------------\n";
}
else
{
std::string rest(iter, end);
std::cout << "-------------------------\n";
std::cout << "Parsing failed\n";
std::cout << "stopped at: \": " << rest << "\"\n";
std::cout << "-------------------------\n";
}
return 0;
}
|
