| /*============================================================================= |
| 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 complex number micro parser. |
| // |
| // [ JDG May 10, 2002 ] spirit1 |
| // [ JDG May 9, 2007 ] spirit2 |
| // |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| #include <boost/config/warning_disable.hpp> |
| #include <boost/spirit/include/qi.hpp> |
| #include <boost/spirit/include/phoenix_core.hpp> |
| #include <boost/spirit/include/phoenix_operator.hpp> |
| |
| #include <iostream> |
| #include <string> |
| #include <complex> |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // Our complex number parser/compiler |
| /////////////////////////////////////////////////////////////////////////////// |
| //[tutorial_complex_number |
| namespace client |
| { |
| template <typename Iterator> |
| bool parse_complex(Iterator first, Iterator last, std::complex<double>& c) |
| { |
| using boost::spirit::qi::double_; |
| using boost::spirit::qi::_1; |
| using boost::spirit::qi::phrase_parse; |
| using boost::spirit::ascii::space; |
| using boost::phoenix::ref; |
| |
| double rN = 0.0; |
| double iN = 0.0; |
| bool r = phrase_parse(first, last, |
| |
| // Begin grammar |
| ( |
| '(' >> double_[ref(rN) = _1] |
| >> -(',' >> double_[ref(iN) = _1]) >> ')' |
| | double_[ref(rN) = _1] |
| ), |
| // End grammar |
| |
| space); |
| |
| if (!r || first != last) // fail if we did not get a full match |
| return false; |
| c = std::complex<double>(rN, iN); |
| return r; |
| } |
| } |
| //] |
| |
| //////////////////////////////////////////////////////////////////////////// |
| // Main program |
| //////////////////////////////////////////////////////////////////////////// |
| int |
| main() |
| { |
| std::cout << "/////////////////////////////////////////////////////////\n\n"; |
| std::cout << "\t\tA complex number micro parser for Spirit...\n\n"; |
| std::cout << "/////////////////////////////////////////////////////////\n\n"; |
| |
| std::cout << "Give me a complex number of the form r or (r) or (r,i) \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::complex<double> c; |
| if (client::parse_complex(str.begin(), str.end(), c)) |
| { |
| std::cout << "-------------------------\n"; |
| std::cout << "Parsing succeeded\n"; |
| std::cout << "got: " << c << 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; |
| } |
| |
| |