133 lines
4.4 KiB
C++
133 lines
4.4 KiB
C++
// Copyright (c) 2001-2010 Hartmut Kaiser
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// Copyright (c) 2001-2010 Joel de Guzman
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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///////////////////////////////////////////////////////////////////////////////
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//
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// A complex number micro generator.
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//
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// [ HK July 7, 2009 ] spirit2
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//
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///////////////////////////////////////////////////////////////////////////////
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#include <boost/config/warning_disable.hpp>
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#include <boost/spirit/include/qi.hpp>
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#include <boost/spirit/include/karma.hpp>
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#include <boost/spirit/include/phoenix_core.hpp>
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#include <boost/spirit/include/phoenix_operator.hpp>
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#include <boost/fusion/include/std_pair.hpp>
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#include <iostream>
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#include <string>
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#include <complex>
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namespace client
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{
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///////////////////////////////////////////////////////////////////////////
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// Our complex number parser/compiler (that's just a copy of the complex
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// number example from Qi (see examples/qi/complex_number.cpp)
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///////////////////////////////////////////////////////////////////////////
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template <typename Iterator>
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bool parse_complex(Iterator first, Iterator last, std::complex<double>& c)
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{
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using boost::spirit::qi::double_;
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using boost::spirit::qi::_1;
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using boost::spirit::qi::phrase_parse;
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using boost::spirit::ascii::space;
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using boost::phoenix::ref;
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double rN = 0.0;
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double iN = 0.0;
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bool r = phrase_parse(first, last,
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(
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'(' >> double_[ref(rN) = _1]
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>> -(',' >> double_[ref(iN) = _1]) >> ')'
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| double_[ref(rN) = _1]
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),
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space);
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if (!r || first != last) // fail if we did not get a full match
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return false;
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c = std::complex<double>(rN, iN);
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return r;
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}
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///////////////////////////////////////////////////////////////////////////
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// Our complex number generator
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///////////////////////////////////////////////////////////////////////////
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//[tutorial_karma_complex_number
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template <typename OutputIterator>
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bool generate_complex(OutputIterator sink, std::complex<double> const& c)
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{
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using boost::spirit::karma::eps;
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using boost::spirit::karma::double_;
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using boost::spirit::karma::_1;
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using boost::spirit::karma::generate;
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return generate(sink,
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// Begin grammar
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(
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eps(c.imag() != 0) <<
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'(' << double_[_1 = c.real()] << ", " << double_[_1 = c.imag()] << ')'
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| double_[_1 = c.real()]
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)
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// End grammar
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);
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}
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//]
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}
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///////////////////////////////////////////////////////////////////////////////
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// Main program
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///////////////////////////////////////////////////////////////////////////////
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int main()
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{
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std::cout << "/////////////////////////////////////////////////////////\n\n";
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std::cout << "\t\tA complex number micro generator for Spirit...\n\n";
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std::cout << "/////////////////////////////////////////////////////////\n\n";
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std::cout << "Give me a complex number of the form r or (r) or (r,i) \n";
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std::cout << "Type [q or Q] to quit\n\n";
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std::string str;
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while (getline(std::cin, str))
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{
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if (str.empty() || str[0] == 'q' || str[0] == 'Q')
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break;
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std::complex<double> c;
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if (client::parse_complex(str.begin(), str.end(), c))
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{
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std::cout << "-------------------------\n";
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std::string generated;
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std::back_insert_iterator<std::string> sink(generated);
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if (!client::generate_complex(sink, c))
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{
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std::cout << "-------------------------\n";
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std::cout << "Generating failed\n";
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std::cout << "-------------------------\n";
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}
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else
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{
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std::cout << "-------------------------\n";
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std::cout << "Generated: " << generated << "\n";
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std::cout << "-------------------------\n";
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}
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}
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else
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{
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std::cout << "-------------------------\n";
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std::cout << "Parsing failed\n";
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std::cout << "-------------------------\n";
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}
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}
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std::cout << "Bye... :-) \n\n";
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return 0;
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}
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