| /*============================================================================= |
| 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 <boost/config/warning_disable.hpp> |
| //[tutorial_adder_includes |
| #include <boost/spirit/include/qi.hpp> |
| #include <boost/spirit/include/phoenix_core.hpp> |
| #include <boost/spirit/include/phoenix_operator.hpp> |
| #include <iostream> |
| #include <string> |
| //] |
| |
| 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 <typename Iterator> |
| 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; |
| } |
| |
| |