spirit/test/x3/real.hpp
2019-05-04 17:47:31 +08:00

123 lines
3.7 KiB
C++

/*=============================================================================
Copyright (c) 2001-2010 Joel de Guzman
Copyright (c) 2001-2010 Hartmut Kaiser
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)
=============================================================================*/
#if !defined(BOOST_SPIRIT_TEST_X3_REAL_HPP)
#define BOOST_SPIRIT_TEST_X3_REAL_HPP
#include <climits>
#include <boost/math/concepts/real_concept.hpp>
#include <boost/detail/lightweight_test.hpp>
#include <boost/spirit/home/x3/char.hpp>
#include <boost/spirit/home/x3/numeric.hpp>
#include <boost/spirit/home/x3/operator.hpp>
#include <boost/math/special_functions/fpclassify.hpp>
#include <boost/math/special_functions/sign.hpp>
#include "test.hpp"
///////////////////////////////////////////////////////////////////////////////
// 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
///////////////////////////////////////////////////////////////////////////////
template <typename T>
struct ts_real_policies : boost::spirit::x3::ureal_policies<T>
{
// 2 decimal places Max
template <typename Iterator, typename Attribute>
static bool
parse_frac_n(Iterator& first, Iterator const& last, Attribute& attr)
{
namespace x3 = boost::spirit::x3;
return boost::spirit::x3::extract_uint<T, 10, 1, 2, true>::call(first, last, attr);
}
// No exponent
template <typename Iterator>
static bool
parse_exp(Iterator&, Iterator const&)
{
return false;
}
// No exponent
template <typename Iterator, typename Attribute>
static bool
parse_exp_n(Iterator&, Iterator const&, Attribute&)
{
return false;
}
// Thousands separated numbers
template <typename Iterator, typename Accumulator>
static bool
parse_n(Iterator& first, Iterator const& last, Accumulator& result)
{
using boost::spirit::x3::uint_parser;
namespace x3 = boost::spirit::x3;
uint_parser<unsigned, 10, 1, 3> uint3;
uint_parser<unsigned, 10, 3, 3> uint3_3;
if (parse(first, last, uint3, result))
{
Accumulator n;
Iterator iter = first;
while (x3::parse(iter, last, ',') && x3::parse(iter, last, uint3_3, n))
{
result = result * 1000 + n;
first = iter;
}
return true;
}
return false;
}
};
template <typename T>
struct no_trailing_dot_policy : boost::spirit::x3::real_policies<T>
{
static bool const allow_trailing_dot = false;
};
template <typename T>
struct no_leading_dot_policy : boost::spirit::x3::real_policies<T>
{
static bool const allow_leading_dot = false;
};
template <typename T, typename T2>
bool
compare(T n, T2 expected)
{
T const eps = std::pow(10.0, -std::numeric_limits<T>::digits10);
T delta = n - expected;
return (delta >= -eps) && (delta <= eps);
}
///////////////////////////////////////////////////////////////////////////////
// A custom real type
struct custom_real
{
double n;
custom_real() : n(0) {}
custom_real(double n_) : n(n_) {}
friend bool operator==(custom_real a, custom_real b)
{ return a.n == b.n; }
friend custom_real operator*(custom_real a, custom_real b)
{ return custom_real(a.n * b.n); }
friend custom_real operator+(custom_real a, custom_real b)
{ return custom_real(a.n + b.n); }
friend custom_real operator-(custom_real a, custom_real b)
{ return custom_real(a.n - b.n); }
};
#endif