Chris@102: /*=============================================================================
Chris@102:     Copyright (c) 2001-2014 Joel de Guzman
Chris@102:     Copyright (c) 2001-2011 Hartmut Kaiser
Chris@102: 
Chris@102:     Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@102:     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@102: ==============================================================================*/
Chris@102: #if !defined(SPIRIT_REAL_POLICIES_APRIL_17_2006_1158PM)
Chris@102: #define SPIRIT_REAL_POLICIES_APRIL_17_2006_1158PM
Chris@102: 
Chris@102: #if defined(_MSC_VER)
Chris@102: #pragma once
Chris@102: #endif
Chris@102: 
Chris@102: #include <boost/spirit/home/x3/string/detail/string_parse.hpp>
Chris@102: #include <boost/spirit/home/x3/support/numeric_utils/extract_int.hpp>
Chris@102: 
Chris@102: namespace boost { namespace spirit { namespace x3
Chris@102: {
Chris@102:     ///////////////////////////////////////////////////////////////////////////
Chris@102:     //  Default (unsigned) real number policies
Chris@102:     ///////////////////////////////////////////////////////////////////////////
Chris@102:     template <typename T>
Chris@102:     struct ureal_policies
Chris@102:     {
Chris@102:         // trailing dot policy suggested by Gustavo Guerra
Chris@102:         static bool const allow_leading_dot = true;
Chris@102:         static bool const allow_trailing_dot = true;
Chris@102:         static bool const expect_dot = false;
Chris@102: 
Chris@102:         template <typename Iterator>
Chris@102:         static bool
Chris@102:         parse_sign(Iterator& /*first*/, Iterator const& /*last*/)
Chris@102:         {
Chris@102:             return false;
Chris@102:         }
Chris@102: 
Chris@102:         template <typename Iterator, typename Attribute>
Chris@102:         static bool
Chris@102:         parse_n(Iterator& first, Iterator const& last, Attribute& attr_)
Chris@102:         {
Chris@102:             return extract_uint<T, 10, 1, -1>::call(first, last, attr_);
Chris@102:         }
Chris@102: 
Chris@102:         template <typename Iterator>
Chris@102:         static bool
Chris@102:         parse_dot(Iterator& first, Iterator const& last)
Chris@102:         {
Chris@102:             if (first == last || *first != '.')
Chris@102:                 return false;
Chris@102:             ++first;
Chris@102:             return true;
Chris@102:         }
Chris@102: 
Chris@102:         template <typename Iterator, typename Attribute>
Chris@102:         static bool
Chris@102:         parse_frac_n(Iterator& first, Iterator const& last, Attribute& attr_)
Chris@102:         {
Chris@102:             return extract_uint<T, 10, 1, -1, true>::call(first, last, attr_);
Chris@102:         }
Chris@102: 
Chris@102:         template <typename Iterator>
Chris@102:         static bool
Chris@102:         parse_exp(Iterator& first, Iterator const& last)
Chris@102:         {
Chris@102:             if (first == last || (*first != 'e' && *first != 'E'))
Chris@102:                 return false;
Chris@102:             ++first;
Chris@102:             return true;
Chris@102:         }
Chris@102: 
Chris@102:         template <typename Iterator>
Chris@102:         static bool
Chris@102:         parse_exp_n(Iterator& first, Iterator const& last, int& attr_)
Chris@102:         {
Chris@102:             return extract_int<int, 10, 1, -1>::call(first, last, attr_);
Chris@102:         }
Chris@102: 
Chris@102:         ///////////////////////////////////////////////////////////////////////
Chris@102:         //  The parse_nan() and parse_inf() functions get called whenever:
Chris@102:         //
Chris@102:         //    - a number to parse does not start with a digit (after having
Chris@102:         //      successfully parsed an optional sign)
Chris@102:         //
Chris@102:         //  or
Chris@102:         //
Chris@102:         //    - after a floating point number of the value 1 (having no
Chris@102:         //      exponential part and a fractional part value of 0) has been
Chris@102:         //      parsed.
Chris@102:         //
Chris@102:         //  The first call allows to recognize representations of NaN or Inf
Chris@102:         //  starting with a non-digit character (such as NaN, Inf, QNaN etc.).
Chris@102:         //
Chris@102:         //  The second call allows to recognize representation formats starting
Chris@102:         //  with a 1.0 (such as 1.0#NAN or 1.0#INF etc.).
Chris@102:         //
Chris@102:         //  The functions should return true if a Nan or Inf has been found. In
Chris@102:         //  this case the attr should be set to the matched value (NaN or
Chris@102:         //  Inf). The optional sign will be automatically applied afterwards.
Chris@102:         //
Chris@102:         //  The default implementation below recognizes representations of NaN
Chris@102:         //  and Inf as mandated by the C99 Standard and as proposed for
Chris@102:         //  inclusion into the C++0x Standard: nan, nan(...), inf and infinity
Chris@102:         //  (the matching is performed case-insensitively).
Chris@102:         ///////////////////////////////////////////////////////////////////////
Chris@102:         template <typename Iterator, typename Attribute>
Chris@102:         static bool
Chris@102:         parse_nan(Iterator& first, Iterator const& last, Attribute& attr_)
Chris@102:         {
Chris@102:             if (first == last)
Chris@102:                 return false;   // end of input reached
Chris@102: 
Chris@102:             if (*first != 'n' && *first != 'N')
Chris@102:                 return false;   // not "nan"
Chris@102: 
Chris@102:             // nan[(...)] ?
Chris@102:             if (detail::string_parse("nan", "NAN", first, last, unused))
Chris@102:             {
Chris@102:                 if (*first == '(')
Chris@102:                 {
Chris@102:                     // skip trailing (...) part
Chris@102:                     Iterator i = first;
Chris@102: 
Chris@102:                     while (++i != last && *i != ')')
Chris@102:                         ;
Chris@102:                     if (i == last)
Chris@102:                         return false;     // no trailing ')' found, give up
Chris@102: 
Chris@102:                     first = ++i;
Chris@102:                 }
Chris@102:                 attr_ = std::numeric_limits<T>::quiet_NaN();
Chris@102:                 return true;
Chris@102:             }
Chris@102:             return false;
Chris@102:         }
Chris@102: 
Chris@102:         template <typename Iterator, typename Attribute>
Chris@102:         static bool
Chris@102:         parse_inf(Iterator& first, Iterator const& last, Attribute& attr_)
Chris@102:         {
Chris@102:             if (first == last)
Chris@102:                 return false;   // end of input reached
Chris@102: 
Chris@102:             if (*first != 'i' && *first != 'I')
Chris@102:                 return false;   // not "inf"
Chris@102: 
Chris@102:             // inf or infinity ?
Chris@102:             if (detail::string_parse("inf", "INF", first, last, unused))
Chris@102:             {
Chris@102:                 // skip allowed 'inity' part of infinity
Chris@102:                 detail::string_parse("inity", "INITY", first, last, unused);
Chris@102:                 attr_ = std::numeric_limits<T>::infinity();
Chris@102:                 return true;
Chris@102:             }
Chris@102:             return false;
Chris@102:         }
Chris@102:     };
Chris@102: 
Chris@102:     ///////////////////////////////////////////////////////////////////////////
Chris@102:     //  Default (signed) real number policies
Chris@102:     ///////////////////////////////////////////////////////////////////////////
Chris@102:     template <typename T>
Chris@102:     struct real_policies : ureal_policies<T>
Chris@102:     {
Chris@102:         template <typename Iterator>
Chris@102:         static bool
Chris@102:         parse_sign(Iterator& first, Iterator const& last)
Chris@102:         {
Chris@102:             return extract_sign(first, last);
Chris@102:         }
Chris@102:     };
Chris@102: 
Chris@102:     template <typename T>
Chris@102:     struct strict_ureal_policies : ureal_policies<T>
Chris@102:     {
Chris@102:         static bool const expect_dot = true;
Chris@102:     };
Chris@102: 
Chris@102:     template <typename T>
Chris@102:     struct strict_real_policies : real_policies<T>
Chris@102:     {
Chris@102:         static bool const expect_dot = true;
Chris@102:     };
Chris@102: }}}
Chris@102: 
Chris@102: #endif