134 lines
4.6 KiB
C++
134 lines
4.6 KiB
C++
/*=============================================================================
|
|
Copyright (c) 2002-2003 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 parser for a real number parser that parses thousands separated numbers
|
|
// with at most two decimal places and no exponent. This is discussed in the
|
|
// "Numerics" chapter in the Spirit User's Guide.
|
|
//
|
|
// [ JDG 12/16/2003 ]
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
#include <boost/spirit/include/classic_core.hpp>
|
|
#include <boost/spirit/include/classic_assign_actor.hpp>
|
|
#include <iostream>
|
|
#include <string>
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
using namespace std;
|
|
using namespace BOOST_SPIRIT_CLASSIC_NS;
|
|
|
|
template <typename T>
|
|
struct ts_real_parser_policies : public ureal_parser_policies<T>
|
|
{
|
|
// These policies can be used to parse thousand separated
|
|
// numbers with at most 2 decimal digits after the decimal
|
|
// point. e.g. 123,456,789.01
|
|
|
|
typedef uint_parser<int, 10, 1, 2> uint2_t;
|
|
typedef uint_parser<T, 10, 1, -1> uint_parser_t;
|
|
typedef int_parser<int, 10, 1, -1> int_parser_t;
|
|
|
|
////////////////////////////////// 2 decimal places Max
|
|
template <typename ScannerT>
|
|
static typename parser_result<uint2_t, ScannerT>::type
|
|
parse_frac_n(ScannerT& scan)
|
|
{ return uint2_t().parse(scan); }
|
|
|
|
////////////////////////////////// No exponent
|
|
template <typename ScannerT>
|
|
static typename parser_result<chlit<>, ScannerT>::type
|
|
parse_exp(ScannerT& scan)
|
|
{ return scan.no_match(); }
|
|
|
|
////////////////////////////////// No exponent
|
|
template <typename ScannerT>
|
|
static typename parser_result<int_parser_t, ScannerT>::type
|
|
parse_exp_n(ScannerT& scan)
|
|
{ return scan.no_match(); }
|
|
|
|
////////////////////////////////// Thousands separated numbers
|
|
template <typename ScannerT>
|
|
static typename parser_result<uint_parser_t, ScannerT>::type
|
|
parse_n(ScannerT& scan)
|
|
{
|
|
typedef typename parser_result<uint_parser_t, ScannerT>::type RT;
|
|
static uint_parser<unsigned, 10, 1, 3> uint3_p;
|
|
static uint_parser<unsigned, 10, 3, 3> uint3_3_p;
|
|
if (RT hit = uint3_p.parse(scan))
|
|
{
|
|
T n;
|
|
typedef typename ScannerT::iterator_t iterator_t;
|
|
iterator_t save = scan.first;
|
|
while (match<> next = (',' >> uint3_3_p[assign_a(n)]).parse(scan))
|
|
{
|
|
hit.value((hit.value() * 1000) + n);
|
|
scan.concat_match(hit, next);
|
|
save = scan.first;
|
|
}
|
|
scan.first = save;
|
|
return hit;
|
|
|
|
// Note: On erroneous input such as "123,45", the result should
|
|
// be a partial match "123". 'save' is used to makes sure that
|
|
// the scanner position is placed at the last *valid* parse
|
|
// position.
|
|
}
|
|
return scan.no_match();
|
|
}
|
|
};
|
|
|
|
real_parser<double, ts_real_parser_policies<double> > const
|
|
ts_real_p = real_parser<double, ts_real_parser_policies<double> >();
|
|
|
|
////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Main program
|
|
//
|
|
////////////////////////////////////////////////////////////////////////////
|
|
int
|
|
main()
|
|
{
|
|
cout << "/////////////////////////////////////////////////////////\n\n";
|
|
cout << "\t\tA real number parser that parses thousands separated\n";
|
|
cout << "\t\tnumbers with at most two decimal places and no exponent...\n\n";
|
|
cout << "/////////////////////////////////////////////////////////\n\n";
|
|
|
|
cout << "Give me a number.\n";
|
|
cout << "Type [q or Q] to quit\n\n";
|
|
|
|
string str;
|
|
double n;
|
|
while (getline(cin, str))
|
|
{
|
|
if (str.empty() || str[0] == 'q' || str[0] == 'Q')
|
|
break;
|
|
|
|
if (parse(str.c_str(), ts_real_p[assign_a(n)]).full)
|
|
{
|
|
cout << "-------------------------\n";
|
|
cout << "Parsing succeeded\n";
|
|
cout << str << " Parses OK: " << endl;
|
|
cout << "n=" << n << endl;
|
|
cout << "-------------------------\n";
|
|
}
|
|
else
|
|
{
|
|
cout << "-------------------------\n";
|
|
cout << "Parsing failed\n";
|
|
cout << "-------------------------\n";
|
|
}
|
|
}
|
|
|
|
cout << "Bye... :-) \n\n";
|
|
return 0;
|
|
}
|
|
|
|
|