libs/spirit/example/karma/num_list3.cpp
/*=============================================================================
Copyright (c) 2002-2010 Hartmut Kaiser
Copyright (c) 2002-2010 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)
=============================================================================*/
///////////////////////////////////////////////////////////////////////////////
//
// This sample demonstrates a generator for a comma separated list of numbers.
// No actions. It is based on the example qi/num_lists.cpp for reading in
// some numbers to generate.
//
///////////////////////////////////////////////////////////////////////////////
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/karma.hpp>
#include <iostream>
#include <string>
#include <vector>
namespace client
{
///////////////////////////////////////////////////////////////////////////
// Our number list parser, please see the example qi/numlist1.cpp for
// more information
///////////////////////////////////////////////////////////////////////////
template <typename Iterator>
bool parse_numbers(Iterator first, Iterator last, std::vector<double>& v)
{
using boost::spirit::qi::double_;
using boost::spirit::qi::phrase_parse;
using boost::spirit::ascii::space;
bool r = phrase_parse(first, last, double_ % ',', space, v);
if (first != last)
return false;
return r;
}
//[tutorial_karma_numlist3_complex
// a simple complex number representation z = a + bi
struct complex
{
complex (double a, double b = 0.0) : a(a), b(b) {}
double a;
double b;
};
// the streaming operator for the type complex
std::ostream&
operator<< (std::ostream& os, complex const& z)
{
os << "{" << z.a << "," << z.b << "}";
return os;
}
//]
///////////////////////////////////////////////////////////////////////////
// Our number list generator
///////////////////////////////////////////////////////////////////////////
//[tutorial_karma_numlist3
template <typename OutputIterator, typename Container>
bool generate_numbers(OutputIterator& sink, Container const& v)
{
using boost::spirit::karma::stream;
using boost::spirit::karma::generate;
using boost::spirit::karma::eol;
bool r = generate(
sink, // destination: output iterator
stream % eol, // the generator
v // the data to output
);
return r;
}
//]
}
////////////////////////////////////////////////////////////////////////////
// Main program
////////////////////////////////////////////////////////////////////////////
int
main()
{
std::cout << "/////////////////////////////////////////////////////////\n\n";
std::cout << "\tA comma separated list generator for Spirit...\n\n";
std::cout << "/////////////////////////////////////////////////////////\n\n";
std::cout << "Give me a comma separated list 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; // here we put the data gotten from input
if (client::parse_numbers(str.begin(), str.end(), v))
{
// ok, we got some numbers, fill a vector of client::complex
// instances and print them back out
std::vector<client::complex> vc;
std::vector<double>::const_iterator end = v.end();
for (std::vector<double>::const_iterator it = v.begin();
it != end; ++it)
{
double real(*it);
if (++it != end)
vc.push_back(client::complex(real, *it));
else {
vc.push_back(client::complex(real));
break;
}
}
std::cout << "-------------------------\n";
std::string generated;
std::back_insert_iterator<std::string> sink(generated);
if (!client::generate_numbers(sink, vc))
{
std::cout << "-------------------------\n";
std::cout << "Generating failed\n";
std::cout << "-------------------------\n";
}
else
{
std::cout << "-------------------------\n";
std::cout << "Generated:\n" << generated << "\n";
std::cout << "-------------------------\n";
}
}
else
{
std::cout << "-------------------------\n";
std::cout << "Parsing failed\n";
std::cout << "-------------------------\n";
}
}
std::cout << "Bye... :-) \n\n";
return 0;
}