/Src/Dependencies/Boost/libs/spirit/example/karma/complex_number_easier.cpp
http://hadesmem.googlecode.com/ · C++ · 133 lines · 89 code · 18 blank · 26 comment · 11 complexity · 8af4c52c3a8d38035a7bd6f726f9e2a7 MD5 · raw file
- // Copyright (c) 2001-2010 Hartmut Kaiser
- // Copyright (c) 2001-2010 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 generator - take 2. Look'ma no semantic actions!
- //
- // [ HK July 26, 2009 ] spirit2
- //
- ///////////////////////////////////////////////////////////////////////////////
- #include <boost/config/warning_disable.hpp>
- #include <boost/spirit/include/qi.hpp>
- #include <boost/spirit/include/karma.hpp>
- #include <boost/spirit/include/phoenix_core.hpp>
- #include <boost/spirit/include/phoenix_operator.hpp>
- #include <boost/fusion/include/std_pair.hpp>
- #include <iostream>
- #include <string>
- #include <complex>
- namespace client
- {
- ///////////////////////////////////////////////////////////////////////////
- // Our complex number parser/compiler (that's just a copy of the complex
- // number example from Qi (see examples/qi/complex_number.cpp)
- ///////////////////////////////////////////////////////////////////////////
- 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,
- (
- '(' >> double_[ref(rN) = _1]
- >> -(',' >> double_[ref(iN) = _1]) >> ')'
- | double_[ref(rN) = _1]
- ),
- space);
- if (!r || first != last) // fail if we did not get a full match
- return false;
- c = std::complex<double>(rN, iN);
- return r;
- }
- ///////////////////////////////////////////////////////////////////////////
- // Our complex number generator
- ///////////////////////////////////////////////////////////////////////////
- //[tutorial_karma_complex_number_easier
- template <typename OutputIterator>
- bool generate_complex(OutputIterator sink, std::complex<double> const& c)
- {
- using boost::spirit::karma::double_;
- using boost::spirit::karma::omit;
- using boost::spirit::karma::generate;
- return generate(sink,
- // Begin grammar
- (
- !double_(0.0) << '(' << double_ << ", " << double_ << ')'
- | omit[double_] << double_
- ),
- // End grammar
- c.imag(), c.real(), c.imag() // Data to output
- );
- }
- //]
- }
- ///////////////////////////////////////////////////////////////////////////////
- // Main program
- ///////////////////////////////////////////////////////////////////////////////
- int main()
- {
- std::cout << "/////////////////////////////////////////////////////////\n\n";
- std::cout << "\t\tA complex number micro generator 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::string generated;
- std::back_insert_iterator<std::string> sink(generated);
- if (!client::generate_complex(sink, c))
- {
- 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;
- }