102 lines
3.2 KiB
C++
102 lines
3.2 KiB
C++
/*=============================================================================
|
|
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;
|
|
}
|
|
|
|
|