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/*=============================================================================
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;
}
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