| /*============================================================================= | |
| 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_IPP | |
| #define BOOST_SPIRIT_NUMERICS_IPP | |
| #include <boost/config/no_tr1/cmath.hpp> | |
| #include <limits> | |
| namespace boost { namespace spirit { | |
| BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN | |
| struct sign_parser; // forward declaration only | |
| namespace impl | |
| { | |
| /////////////////////////////////////////////////////////////////////// | |
| // | |
| // Extract the prefix sign (- or +) | |
| // | |
| /////////////////////////////////////////////////////////////////////// | |
| template <typename ScannerT> | |
| bool | |
| extract_sign(ScannerT const& scan, std::size_t& count) | |
| { | |
| // Extract the sign | |
| count = 0; | |
| bool neg = *scan == '-'; | |
| if (neg || (*scan == '+')) | |
| { | |
| ++scan; | |
| ++count; | |
| return neg; | |
| } | |
| return false; | |
| } | |
| /////////////////////////////////////////////////////////////////////// | |
| // | |
| // Traits class for radix specific number conversion | |
| // | |
| // Convert a digit from character representation, ch, to binary | |
| // representation, returned in val. | |
| // Returns whether the conversion was successful. | |
| // | |
| // template<typename CharT> static bool digit(CharT ch, T& val); | |
| // | |
| /////////////////////////////////////////////////////////////////////// | |
| template<const int Radix> | |
| struct radix_traits; | |
| ////////////////////////////////// Binary | |
| template<> | |
| struct radix_traits<2> | |
| { | |
| template<typename CharT, typename T> | |
| static bool digit(CharT ch, T& val) | |
| { | |
| val = ch - '0'; | |
| return ('0' == ch || '1' == ch); | |
| } | |
| }; | |
| ////////////////////////////////// Octal | |
| template<> | |
| struct radix_traits<8> | |
| { | |
| template<typename CharT, typename T> | |
| static bool digit(CharT ch, T& val) | |
| { | |
| val = ch - '0'; | |
| return ('0' <= ch && ch <= '7'); | |
| } | |
| }; | |
| ////////////////////////////////// Decimal | |
| template<> | |
| struct radix_traits<10> | |
| { | |
| template<typename CharT, typename T> | |
| static bool digit(CharT ch, T& val) | |
| { | |
| val = ch - '0'; | |
| return impl::isdigit_(ch); | |
| } | |
| }; | |
| ////////////////////////////////// Hexadecimal | |
| template<> | |
| struct radix_traits<16> | |
| { | |
| template<typename CharT, typename T> | |
| static bool digit(CharT ch, T& val) | |
| { | |
| if (radix_traits<10>::digit(ch, val)) | |
| return true; | |
| CharT lc = impl::tolower_(ch); | |
| if ('a' <= lc && lc <= 'f') | |
| { | |
| val = lc - 'a' + 10; | |
| return true; | |
| } | |
| return false; | |
| } | |
| }; | |
| /////////////////////////////////////////////////////////////////////// | |
| // | |
| // Helper templates for encapsulation of radix specific | |
| // conversion of an input string to an integral value. | |
| // | |
| // main entry point: | |
| // | |
| // extract_int<Radix, MinDigits, MaxDigits, Accumulate> | |
| // ::f(first, last, n, count); | |
| // | |
| // The template parameter Radix represents the radix of the | |
| // number contained in the parsed string. The template | |
| // parameter MinDigits specifies the minimum digits to | |
| // accept. The template parameter MaxDigits specifies the | |
| // maximum digits to parse. A -1 value for MaxDigits will | |
| // make it parse an arbitrarilly large number as long as the | |
| // numeric type can hold it. Accumulate is either | |
| // positive_accumulate<Radix> (default) for parsing positive | |
| // numbers or negative_accumulate<Radix> otherwise. | |
| // Checking is only performed when std::numeric_limits<T>:: | |
| // is_specialized is true. Otherwise, there's no way to | |
| // do the check. | |
| // | |
| // scan.first and scan.last are iterators as usual (i.e. | |
| // first is mutable and is moved forward when a match is | |
| // found), n is a variable that holds the number (passed by | |
| // reference). The number of parsed characters is added to | |
| // count (also passed by reference) | |
| // | |
| // NOTE: | |
| // Returns a non-match, if the number to parse | |
| // overflows (or underflows) the used type. | |
| // | |
| // BEWARE: | |
| // the parameters 'n' and 'count' should be properly | |
| // initialized before calling this function. | |
| // | |
| /////////////////////////////////////////////////////////////////////// | |
| #if defined(BOOST_MSVC) | |
| #pragma warning(push) | |
| #pragma warning(disable:4127) //conditional expression is constant | |
| #endif | |
| template <typename T, int Radix> | |
| struct positive_accumulate | |
| { | |
| // Use this accumulator if number is positive | |
| static bool add(T& n, T digit) | |
| { | |
| if (std::numeric_limits<T>::is_specialized) | |
| { | |
| static T const max = (std::numeric_limits<T>::max)(); | |
| static T const max_div_radix = max/Radix; | |
| if (n > max_div_radix) | |
| return false; | |
| n *= Radix; | |
| if (n > max - digit) | |
| return false; | |
| n += digit; | |
| return true; | |
| } | |
| else | |
| { | |
| n *= Radix; | |
| n += digit; | |
| return true; | |
| } | |
| } | |
| }; | |
| template <typename T, int Radix> | |
| struct negative_accumulate | |
| { | |
| // Use this accumulator if number is negative | |
| static bool add(T& n, T digit) | |
| { | |
| if (std::numeric_limits<T>::is_specialized) | |
| { | |
| typedef std::numeric_limits<T> num_limits; | |
| static T const min = | |
| (!num_limits::is_integer && num_limits::is_signed && num_limits::has_denorm) ? | |
| -(num_limits::max)() : (num_limits::min)(); | |
| static T const min_div_radix = min/Radix; | |
| if (n < min_div_radix) | |
| return false; | |
| n *= Radix; | |
| if (n < min + digit) | |
| return false; | |
| n -= digit; | |
| return true; | |
| } | |
| else | |
| { | |
| n *= Radix; | |
| n -= digit; | |
| return true; | |
| } | |
| } | |
| }; | |
| template <int MaxDigits> | |
| inline bool allow_more_digits(std::size_t i) | |
| { | |
| return i < MaxDigits; | |
| } | |
| template <> | |
| inline bool allow_more_digits<-1>(std::size_t) | |
| { | |
| return true; | |
| } | |
| ////////////////////////////////// | |
| template < | |
| int Radix, unsigned MinDigits, int MaxDigits, | |
| typename Accumulate | |
| > | |
| struct extract_int | |
| { | |
| template <typename ScannerT, typename T> | |
| static bool | |
| f(ScannerT& scan, T& n, std::size_t& count) | |
| { | |
| std::size_t i = 0; | |
| T digit; | |
| while( allow_more_digits<MaxDigits>(i) && !scan.at_end() && | |
| radix_traits<Radix>::digit(*scan, digit) ) | |
| { | |
| if (!Accumulate::add(n, digit)) | |
| return false; // Overflow | |
| ++i, ++scan, ++count; | |
| } | |
| return i >= MinDigits; | |
| } | |
| }; | |
| /////////////////////////////////////////////////////////////////////// | |
| // | |
| // uint_parser_impl class | |
| // | |
| /////////////////////////////////////////////////////////////////////// | |
| template < | |
| typename T = unsigned, | |
| int Radix = 10, | |
| unsigned MinDigits = 1, | |
| int MaxDigits = -1 | |
| > | |
| struct uint_parser_impl | |
| : parser<uint_parser_impl<T, Radix, MinDigits, MaxDigits> > | |
| { | |
| typedef uint_parser_impl<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 | |
| { | |
| if (!scan.at_end()) | |
| { | |
| T n = 0; | |
| std::size_t count = 0; | |
| typename ScannerT::iterator_t save = scan.first; | |
| if (extract_int<Radix, MinDigits, MaxDigits, | |
| positive_accumulate<T, Radix> >::f(scan, n, count)) | |
| { | |
| return scan.create_match(count, n, save, scan.first); | |
| } | |
| // return no-match if number overflows | |
| } | |
| return scan.no_match(); | |
| } | |
| }; | |
| /////////////////////////////////////////////////////////////////////// | |
| // | |
| // int_parser_impl class | |
| // | |
| /////////////////////////////////////////////////////////////////////// | |
| template < | |
| typename T = unsigned, | |
| int Radix = 10, | |
| unsigned MinDigits = 1, | |
| int MaxDigits = -1 | |
| > | |
| struct int_parser_impl | |
| : parser<int_parser_impl<T, Radix, MinDigits, MaxDigits> > | |
| { | |
| typedef int_parser_impl<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 extract_int<Radix, MinDigits, MaxDigits, | |
| negative_accumulate<T, Radix> > extract_int_neg_t; | |
| typedef extract_int<Radix, MinDigits, MaxDigits, | |
| positive_accumulate<T, Radix> > extract_int_pos_t; | |
| if (!scan.at_end()) | |
| { | |
| T n = 0; | |
| std::size_t count = 0; | |
| typename ScannerT::iterator_t save = scan.first; | |
| bool hit = impl::extract_sign(scan, count); | |
| if (hit) | |
| hit = extract_int_neg_t::f(scan, n, count); | |
| else | |
| hit = extract_int_pos_t::f(scan, n, count); | |
| if (hit) | |
| return scan.create_match(count, n, save, scan.first); | |
| else | |
| scan.first = save; | |
| // return no-match if number overflows or underflows | |
| } | |
| return scan.no_match(); | |
| } | |
| }; | |
| /////////////////////////////////////////////////////////////////////// | |
| // | |
| // real_parser_impl class | |
| // | |
| /////////////////////////////////////////////////////////////////////// | |
| template <typename RT, typename T, typename RealPoliciesT> | |
| struct real_parser_impl | |
| { | |
| typedef real_parser_impl<RT, T, RealPoliciesT> self_t; | |
| template <typename ScannerT> | |
| RT parse_main(ScannerT const& scan) const | |
| { | |
| if (scan.at_end()) | |
| return scan.no_match(); | |
| typename ScannerT::iterator_t save = scan.first; | |
| typedef typename parser_result<sign_parser, ScannerT>::type | |
| sign_match_t; | |
| typedef typename parser_result<chlit<>, ScannerT>::type | |
| exp_match_t; | |
| sign_match_t sign_match = RealPoliciesT::parse_sign(scan); | |
| std::size_t count = sign_match ? sign_match.length() : 0; | |
| bool neg = sign_match.has_valid_attribute() ? | |
| sign_match.value() : false; | |
| RT n_match = RealPoliciesT::parse_n(scan); | |
| T n = n_match.has_valid_attribute() ? | |
| n_match.value() : T(0); | |
| bool got_a_number = n_match; | |
| exp_match_t e_hit; | |
| if (!got_a_number && !RealPoliciesT::allow_leading_dot) | |
| return scan.no_match(); | |
| else | |
| count += n_match.length(); | |
| if (neg) | |
| n = -n; | |
| if (RealPoliciesT::parse_dot(scan)) | |
| { | |
| // We got the decimal point. Now we will try to parse | |
| // the fraction if it is there. If not, it defaults | |
| // to zero (0) only if we already got a number. | |
| if (RT hit = RealPoliciesT::parse_frac_n(scan)) | |
| { | |
| #if !defined(BOOST_NO_STDC_NAMESPACE) | |
| using namespace std; // allow for ADL to find pow() | |
| #endif | |
| hit.value(hit.value() | |
| * pow(T(10), T(-hit.length()))); | |
| if (neg) | |
| n -= hit.value(); | |
| else | |
| n += hit.value(); | |
| count += hit.length() + 1; | |
| } | |
| else if (!got_a_number || | |
| !RealPoliciesT::allow_trailing_dot) | |
| return scan.no_match(); | |
| e_hit = RealPoliciesT::parse_exp(scan); | |
| } | |
| else | |
| { | |
| // We have reached a point where we | |
| // still haven't seen a number at all. | |
| // We return early with a no-match. | |
| if (!got_a_number) | |
| return scan.no_match(); | |
| // If we must expect a dot and we didn't see | |
| // an exponent, return early with a no-match. | |
| e_hit = RealPoliciesT::parse_exp(scan); | |
| if (RealPoliciesT::expect_dot && !e_hit) | |
| return scan.no_match(); | |
| } | |
| if (e_hit) | |
| { | |
| // We got the exponent prefix. Now we will try to parse the | |
| // actual exponent. It is an error if it is not there. | |
| if (RT e_n_hit = RealPoliciesT::parse_exp_n(scan)) | |
| { | |
| #if !defined(BOOST_NO_STDC_NAMESPACE) | |
| using namespace std; // allow for ADL to find pow() | |
| #endif | |
| n *= pow(T(10), T(e_n_hit.value())); | |
| count += e_n_hit.length() + e_hit.length(); | |
| } | |
| else | |
| { | |
| // Oops, no exponent, return a no-match | |
| return scan.no_match(); | |
| } | |
| } | |
| return scan.create_match(count, n, save, scan.first); | |
| } | |
| template <typename ScannerT> | |
| static RT parse(ScannerT const& scan) | |
| { | |
| static self_t this_; | |
| return impl::implicit_lexeme_parse<RT>(this_, scan, scan); | |
| } | |
| }; | |
| #if defined(BOOST_MSVC) | |
| #pragma warning(pop) | |
| #endif | |
| } // namespace impl | |
| /////////////////////////////////////////////////////////////////////////////// | |
| BOOST_SPIRIT_CLASSIC_NAMESPACE_END | |
| }} // namespace boost::spirit | |
| #endif |