boost/spirit/core/primitives/numerics.hpp
/*=============================================================================
Copyright (c) 1998-2003 Joel de Guzman
Copyright (c) 2001-2003 Hartmut Kaiser
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)
=============================================================================*/
#ifndef BOOST_SPIRIT_NUMERICS_HPP
#define BOOST_SPIRIT_NUMERICS_HPP
#include <boost/config.hpp>
#include <boost/spirit/core/parser.hpp>
#include <boost/spirit/core/composite/directives.hpp>
#include <boost/spirit/core/primitives/impl/numerics.ipp>
namespace boost { namespace spirit
{
///////////////////////////////////////////////////////////////////////////
//
// uint_parser class
//
///////////////////////////////////////////////////////////////////////////
template <
typename T = unsigned,
int Radix = 10,
unsigned MinDigits = 1,
int MaxDigits = -1
>
struct uint_parser : parser<uint_parser<T, Radix, MinDigits, MaxDigits> >
{
typedef uint_parser<T, Radix, MinDigits, MaxDigits> self_t;
template <typename ScannerT>
struct result
{
typedef typename match_result<ScannerT, T>::type type;
};
template <typename ScannerT>
typename parser_result<self_t, ScannerT>::type
parse(ScannerT const& scan) const
{
typedef impl::uint_parser_impl<T, Radix, MinDigits, MaxDigits> impl_t;
typedef typename parser_result<impl_t, ScannerT>::type result_t;
return impl::contiguous_parser_parse<result_t>(impl_t(), scan, scan);
}
};
///////////////////////////////////////////////////////////////////////////
//
// int_parser class
//
///////////////////////////////////////////////////////////////////////////
template <
typename T = unsigned,
int Radix = 10,
unsigned MinDigits = 1,
int MaxDigits = -1
>
struct int_parser : parser<int_parser<T, Radix, MinDigits, MaxDigits> >
{
typedef int_parser<T, Radix, MinDigits, MaxDigits> self_t;
template <typename ScannerT>
struct result
{
typedef typename match_result<ScannerT, T>::type type;
};
template <typename ScannerT>
typename parser_result<self_t, ScannerT>::type
parse(ScannerT const& scan) const
{
typedef impl::int_parser_impl<T, Radix, MinDigits, MaxDigits> impl_t;
typedef typename parser_result<impl_t, ScannerT>::type result_t;
return impl::contiguous_parser_parse<result_t>(impl_t(), scan, scan);
}
};
///////////////////////////////////////////////////////////////////////////
//
// uint_parser/int_parser instantiations
//
///////////////////////////////////////////////////////////////////////////
int_parser<int> const
int_p = int_parser<int>();
uint_parser<unsigned> const
uint_p = uint_parser<unsigned>();
uint_parser<unsigned, 2> const
bin_p = uint_parser<unsigned, 2>();
uint_parser<unsigned, 8> const
oct_p = uint_parser<unsigned, 8>();
uint_parser<unsigned, 16> const
hex_p = uint_parser<unsigned, 16>();
///////////////////////////////////////////////////////////////////////////
//
// sign_parser class
//
///////////////////////////////////////////////////////////////////////////
namespace impl
{
// Utility to extract the prefix sign ('-' | '+')
template <typename ScannerT>
bool extract_sign(ScannerT const& scan, std::size_t& count);
}
struct sign_parser : public parser<sign_parser>
{
typedef sign_parser self_t;
template <typename ScannerT>
struct result
{
typedef typename match_result<ScannerT, bool>::type type;
};
sign_parser() {}
template <typename ScannerT>
typename parser_result<self_t, ScannerT>::type
parse(ScannerT const& scan) const
{
if (!scan.at_end())
{
std::size_t length;
typename ScannerT::iterator_t save(scan.first);
bool neg = impl::extract_sign(scan, length);
if (length)
return scan.create_match(1, neg, save, scan.first);
}
return scan.no_match();
}
};
sign_parser const sign_p = sign_parser();
///////////////////////////////////////////////////////////////////////////
//
// default real number policies
//
///////////////////////////////////////////////////////////////////////////
template <typename T>
struct ureal_parser_policies
{
// trailing dot policy suggested suggested by Gustavo Guerra
BOOST_STATIC_CONSTANT(bool, allow_leading_dot = true);
BOOST_STATIC_CONSTANT(bool, allow_trailing_dot = true);
BOOST_STATIC_CONSTANT(bool, expect_dot = false);
typedef uint_parser<T, 10, 1, -1> uint_parser_t;
typedef int_parser<T, 10, 1, -1> int_parser_t;
template <typename ScannerT>
static typename match_result<ScannerT, nil_t>::type
parse_sign(ScannerT& scan)
{
return scan.no_match();
}
template <typename ScannerT>
static typename parser_result<uint_parser_t, ScannerT>::type
parse_n(ScannerT& scan)
{
return uint_parser_t().parse(scan);
}
template <typename ScannerT>
static typename parser_result<chlit<>, ScannerT>::type
parse_dot(ScannerT& scan)
{
return ch_p('.').parse(scan);
}
template <typename ScannerT>
static typename parser_result<uint_parser_t, ScannerT>::type
parse_frac_n(ScannerT& scan)
{
return uint_parser_t().parse(scan);
}
template <typename ScannerT>
static typename parser_result<chlit<>, ScannerT>::type
parse_exp(ScannerT& scan)
{
return as_lower_d['e'].parse(scan);
}
template <typename ScannerT>
static typename parser_result<int_parser_t, ScannerT>::type
parse_exp_n(ScannerT& scan)
{
return int_parser_t().parse(scan);
}
};
template <typename T>
struct real_parser_policies : public ureal_parser_policies<T>
{
template <typename ScannerT>
static typename parser_result<sign_parser, ScannerT>::type
parse_sign(ScannerT& scan)
{
return sign_p.parse(scan);
}
};
///////////////////////////////////////////////////////////////////////////
//
// real_parser class
//
///////////////////////////////////////////////////////////////////////////
template <
typename T = double,
typename RealPoliciesT = ureal_parser_policies<T>
>
struct real_parser
: public parser<real_parser<T, RealPoliciesT> >
{
typedef real_parser<T, RealPoliciesT> self_t;
template <typename ScannerT>
struct result
{
typedef typename match_result<ScannerT, T>::type type;
};
real_parser() {}
template <typename ScannerT>
typename parser_result<self_t, ScannerT>::type
parse(ScannerT const& scan) const
{
typedef typename parser_result<self_t, ScannerT>::type result_t;
return impl::real_parser_impl<result_t, T, RealPoliciesT>::parse(scan);
}
};
///////////////////////////////////////////////////////////////////////////
//
// real_parser instantiations
//
///////////////////////////////////////////////////////////////////////////
real_parser<double, ureal_parser_policies<double> > const
ureal_p = real_parser<double, ureal_parser_policies<double> >();
real_parser<double, real_parser_policies<double> > const
real_p = real_parser<double, real_parser_policies<double> >();
///////////////////////////////////////////////////////////////////////////
//
// strict reals (do not allow plain integers (no decimal point))
//
///////////////////////////////////////////////////////////////////////////
template <typename T>
struct strict_ureal_parser_policies : public ureal_parser_policies<T>
{
BOOST_STATIC_CONSTANT(bool, expect_dot = true);
};
template <typename T>
struct strict_real_parser_policies : public real_parser_policies<T>
{
BOOST_STATIC_CONSTANT(bool, expect_dot = true);
};
real_parser<double, strict_ureal_parser_policies<double> > const
strict_ureal_p
= real_parser<double, strict_ureal_parser_policies<double> >();
real_parser<double, strict_real_parser_policies<double> > const
strict_real_p
= real_parser<double, strict_real_parser_policies<double> >();
}} // namespace boost::spirit
#endif
