/*============================================================================= 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) =============================================================================*/ /////////////////////////////////////////////////////////////////////////////// // // A parser for summing a comma-separated list of numbers using phoenix. // // [ JDG June 28, 2002 ] spirit1 // [ JDG March 24, 2007 ] spirit2 // /////////////////////////////////////////////////////////////////////////////// #include //[tutorial_adder_includes #include #include #include #include #include //] namespace client { //[tutorial_adder_using namespace qi = boost::spirit::qi; namespace ascii = boost::spirit::ascii; namespace phoenix = boost::phoenix; using qi::double_; using qi::_1; using ascii::space; using phoenix::ref; //] /////////////////////////////////////////////////////////////////////////// // Our adder /////////////////////////////////////////////////////////////////////////// //[tutorial_adder template bool adder(Iterator first, Iterator last, double& n) { bool r = qi::phrase_parse(first, last, // Begin grammar ( double_[ref(n) = _1] >> *(',' >> double_[ref(n) += _1]) ) , // 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 parser for summing a list of numbers...\n\n"; std::cout << "/////////////////////////////////////////////////////////\n\n"; std::cout << "Give me a comma separated list of numbers.\n"; std::cout << "The numbers are added using Phoenix.\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; double n; if (client::adder(str.begin(), str.end(), n)) { std::cout << "-------------------------\n"; std::cout << "Parsing succeeded\n"; std::cout << str << " Parses OK: " << std::endl; std::cout << "sum = " << n; std::cout << "\n-------------------------\n"; } else { std::cout << "-------------------------\n"; std::cout << "Parsing failed\n"; std::cout << "-------------------------\n"; } } std::cout << "Bye... :-) \n\n"; return 0; }