Boost C++ Libraries

libs/spirit/example/karma/num_list2.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/config/warning_disable.hpp>
#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;
    }

    ///////////////////////////////////////////////////////////////////////////
    //  Our number list generator
    ///////////////////////////////////////////////////////////////////////////
    //[tutorial_karma_numlist2
    template <typename OutputIterator, typename Container>
    bool generate_numbers(OutputIterator& sink, Container const& v)
    {
        using boost::spirit::karma::double_;
        using boost::spirit::karma::generate_delimited;
        using boost::spirit::ascii::space;

        bool r = generate_delimited(
            sink,                           // destination: output iterator
            double_ % ',',                  // the generator
            space,                          // the delimiter-generator
            v                               // the data to output 
        );
        return r;
    }
    //]
}

////////////////////////////////////////////////////////////////////////////
//  Main program
////////////////////////////////////////////////////////////////////////////
int
main()
{
    std::cout << "/////////////////////////////////////////////////////////\n\n";
    std::cout << "\t\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 to generate
        if (client::parse_numbers(str.begin(), str.end(), v))
        {
            // ok, we got some numbers, now print them back out
            std::cout << "-------------------------\n";

            std::string generated;
            std::back_insert_iterator<std::string> sink(generated);
            if (!client::generate_numbers(sink, v))
            {
                std::cout << "-------------------------\n";
                std::cout << "Generating failed\n";
                std::cout << "-------------------------\n";
            }
            else
            {
                std::cout << "-------------------------\n";
                std::cout << "Generated: " << generated << "\n";
                std::cout << "-------------------------\n";
            }
        }
        else
        {
            std::cout << "-------------------------\n";
            std::cout << "Parsing failed\n";
            std::cout << "-------------------------\n";
        }
    }

    std::cout << "Bye... :-) \n\n";
    return 0;
}