104 lines
2.8 KiB
C++
104 lines
2.8 KiB
C++
/*=============================================================================
|
|
Copyright (c) 2001-2003 Joel de Guzman
|
|
http://spirit.sourceforge.net/
|
|
|
|
Use, modification and distribution is subject to 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 (using subrules)
|
|
//
|
|
// [ JDG 5/10/2002 ]
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
#include <boost/spirit/include/classic_core.hpp>
|
|
#include <iostream>
|
|
#include <complex>
|
|
#include <string>
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
using namespace std;
|
|
using namespace BOOST_SPIRIT_CLASSIC_NS;
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Our complex number micro parser
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
bool
|
|
parse_complex(char const* str, complex<double>& c)
|
|
{
|
|
double rN = 0.0;
|
|
double iN = 0.0;
|
|
|
|
subrule<0> first;
|
|
subrule<1> r;
|
|
subrule<2> i;
|
|
|
|
if (parse(str,
|
|
|
|
// Begin grammar
|
|
(
|
|
first = '(' >> r >> !(',' >> i) >> ')' | r,
|
|
r = real_p[assign(rN)],
|
|
i = real_p[assign(iN)]
|
|
)
|
|
,
|
|
// End grammar
|
|
|
|
space_p).full)
|
|
{
|
|
c = complex<double>(rN, iN);
|
|
return true;
|
|
}
|
|
else
|
|
{
|
|
return false;
|
|
}
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Main program
|
|
//
|
|
////////////////////////////////////////////////////////////////////////////
|
|
int
|
|
main()
|
|
{
|
|
cout << "/////////////////////////////////////////////////////////\n\n";
|
|
cout << "\t\tA complex number micro parser for Spirit...\n\n";
|
|
cout << "/////////////////////////////////////////////////////////\n\n";
|
|
|
|
cout << "Give me a complex number of the form r or (r) or (r,i) \n";
|
|
cout << "Type [q or Q] to quit\n\n";
|
|
|
|
string str;
|
|
while (getline(cin, str))
|
|
{
|
|
if (str.empty() || str[0] == 'q' || str[0] == 'Q')
|
|
break;
|
|
|
|
complex<double> c;
|
|
if (parse_complex(str.c_str(), c))
|
|
{
|
|
cout << "-------------------------\n";
|
|
cout << "Parsing succeeded\n";
|
|
cout << str << " Parses OK: " << c << endl;
|
|
cout << "-------------------------\n";
|
|
}
|
|
else
|
|
{
|
|
cout << "-------------------------\n";
|
|
cout << "Parsing failed\n";
|
|
cout << "-------------------------\n";
|
|
}
|
|
}
|
|
|
|
cout << "Bye... :-) \n\n";
|
|
return 0;
|
|
}
|
|
|
|
|