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
99
100
|
/*=============================================================================
Copyright (c) 2002-2015 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)
=============================================================================*/
///////////////////////////////////////////////////////////////////////////////
//
// This sample demontrates a parser for a comma separated list of numbers.
//
// [ JDG May 10, 2002 ] spirit1
// [ JDG March 24, 2007 ] spirit2
// [ JDG May 12, 2015 ] spirit X3
//
///////////////////////////////////////////////////////////////////////////////
#include <boost/spirit/home/x3.hpp>
#include <iostream>
#include <string>
#include <vector>
namespace client
{
namespace x3 = boost::spirit::x3;
namespace ascii = boost::spirit::x3::ascii;
///////////////////////////////////////////////////////////////////////////
// Our number list compiler
///////////////////////////////////////////////////////////////////////////
template <typename Iterator>
bool parse_numbers(Iterator first, Iterator last, std::vector<double>& v)
{
using x3::double_;
using x3::phrase_parse;
using x3::_attr;
using ascii::space;
auto push_back = [&](auto& ctx){ v.push_back(_attr(ctx)); };
bool r = phrase_parse(first, last,
// Begin grammar
(
double_[push_back] % ','
)
,
// End grammar
space);
if (first != last) // fail if we did not get a full match
return false;
return r;
}
}
////////////////////////////////////////////////////////////////////////////
// Main program
////////////////////////////////////////////////////////////////////////////
int
main()
{
std::cout << "/////////////////////////////////////////////////////////\n\n";
std::cout << "\t\tA comma separated list parser for Spirit...\n\n";
std::cout << "/////////////////////////////////////////////////////////\n\n";
std::cout << "Give me a comma separated list of numbers.\n";
std::cout << "The numbers will be inserted in a vector of numbers\n";
std::cout << "Type [q or Q] to quit\n\n";
std::string str;
while (getline(std::cin, str))
{
if (str.empty() || str[0] == 'q' || str[0] == 'Q')
break;
std::vector<double> v;
if (client::parse_numbers(str.begin(), str.end(), v))
{
std::cout << "-------------------------\n";
std::cout << "Parsing succeeded\n";
std::cout << str << " Parses OK: " << std::endl;
for (std::vector<double>::size_type i = 0; i < v.size(); ++i)
std::cout << i << ": " << v[i] << std::endl;
std::cout << "\n-------------------------\n";
}
else
{
std::cout << "-------------------------\n";
std::cout << "Parsing failed\n";
std::cout << "-------------------------\n";
}
}
std::cout << "Bye... :-) \n\n";
return 0;
}
|
