/*============================================================================= 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 #include #include #include #include namespace client { namespace x3 = boost::spirit::x3; namespace ascii = boost::spirit::x3::ascii; /////////////////////////////////////////////////////////////////////////// // Our number list compiler /////////////////////////////////////////////////////////////////////////// template bool parse_numbers(Iterator first, Iterator last, std::vector& 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] >> *(',' >> 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 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::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; }