Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // hash_peek_bitset.hpp
Chris@16: //
Chris@16: //  Copyright 2008 Eric Niebler. Distributed under the Boost
Chris@16: //  Software License, Version 1.0. (See accompanying file
Chris@16: //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_XPRESSIVE_DETAIL_HASH_PEEK_BITSET_HPP_EAN_10_04_2005
Chris@16: #define BOOST_XPRESSIVE_DETAIL_HASH_PEEK_BITSET_HPP_EAN_10_04_2005
Chris@16: 
Chris@16: // MS compatible compilers support #pragma once
Chris@101: #if defined(_MSC_VER)
Chris@16: # pragma once
Chris@16: # pragma warning(push)
Chris@16: # pragma warning(disable : 4100) // unreferenced formal parameter
Chris@16: # pragma warning(disable : 4127) // conditional expression constant
Chris@16: #endif
Chris@16: 
Chris@16: #include <bitset>
Chris@16: #include <string> // for std::char_traits
Chris@16: #include <boost/xpressive/detail/utility/chset/basic_chset.ipp>
Chris@16: 
Chris@16: namespace boost { namespace xpressive { namespace detail
Chris@16: {
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // hash_peek_bitset
Chris@16: //
Chris@16: template<typename Char>
Chris@16: struct hash_peek_bitset
Chris@16: {
Chris@16:     typedef Char char_type;
Chris@16:     typedef typename std::char_traits<char_type>::int_type int_type;
Chris@16: 
Chris@16:     hash_peek_bitset()
Chris@16:       : icase_(false)
Chris@16:       , bset_()
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     std::size_t count() const
Chris@16:     {
Chris@16:         return this->bset_.count();
Chris@16:     }
Chris@16: 
Chris@16:     void set_all()
Chris@16:     {
Chris@16:         this->icase_ = false;
Chris@16:         this->bset_.set();
Chris@16:     }
Chris@16: 
Chris@16:     template<typename Traits>
Chris@16:     void set_char(char_type ch, bool icase, Traits const &tr)
Chris@16:     {
Chris@16:         if(this->test_icase_(icase))
Chris@16:         {
Chris@16:             ch = icase ? tr.translate_nocase(ch) : tr.translate(ch);
Chris@16:             this->bset_.set(tr.hash(ch));
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     template<typename Traits>
Chris@16:     void set_range(char_type from, char_type to, bool no, bool icase, Traits const &tr)
Chris@16:     {
Chris@16:         int_type ifrom = std::char_traits<char_type>::to_int_type(from);
Chris@16:         int_type ito = std::char_traits<char_type>::to_int_type(to);
Chris@16:         BOOST_ASSERT(ifrom <= ito);
Chris@16:         // bound the computational complexity. BUGBUG could set the inverse range
Chris@16:         if(no || 256 < (ito - ifrom))
Chris@16:         {
Chris@16:             this->set_all();
Chris@16:         }
Chris@16:         else if(this->test_icase_(icase))
Chris@16:         {
Chris@16:             for(int_type i = ifrom; i <= ito; ++i)
Chris@16:             {
Chris@16:                 char_type ch = std::char_traits<char_type>::to_char_type(i);
Chris@16:                 ch = icase ? tr.translate_nocase(ch) : tr.translate(ch);
Chris@16:                 this->bset_.set(tr.hash(ch));
Chris@16:             }
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     template<typename Traits>
Chris@16:     void set_class(typename Traits::char_class_type char_class, bool no, Traits const &tr)
Chris@16:     {
Chris@16:         if(1 != sizeof(char_type))
Chris@16:         {
Chris@16:             // wide character set, no efficient way of filling in the bitset, so set them all to 1
Chris@16:             this->set_all();
Chris@16:         }
Chris@16:         else
Chris@16:         {
Chris@16:             for(std::size_t i = 0; i <= UCHAR_MAX; ++i)
Chris@16:             {
Chris@16:                 char_type ch = std::char_traits<char_type>::to_char_type(static_cast<int_type>(i));
Chris@16:                 if(no != tr.isctype(ch, char_class))
Chris@16:                 {
Chris@16:                     this->bset_.set(i);
Chris@16:                 }
Chris@16:             }
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     void set_bitset(hash_peek_bitset<Char> const &that)
Chris@16:     {
Chris@16:         if(this->test_icase_(that.icase()))
Chris@16:         {
Chris@16:             this->bset_ |= that.bset_;
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     void set_charset(basic_chset_8bit<Char> const &that, bool icase)
Chris@16:     {
Chris@16:         if(this->test_icase_(icase))
Chris@16:         {
Chris@16:             this->bset_ |= that.base();
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     bool icase() const
Chris@16:     {
Chris@16:         return this->icase_;
Chris@16:     }
Chris@16: 
Chris@16:     template<typename Traits>
Chris@16:     bool test(char_type ch, Traits const &tr) const
Chris@16:     {
Chris@16:         ch = this->icase_ ? tr.translate_nocase(ch) : tr.translate(ch);
Chris@16:         return this->bset_.test(tr.hash(ch));
Chris@16:     }
Chris@16: 
Chris@16:     template<typename Traits>
Chris@16:     bool test(char_type ch, Traits const &tr, mpl::false_) const
Chris@16:     {
Chris@16:         BOOST_ASSERT(!this->icase_);
Chris@16:         return this->bset_.test(tr.hash(tr.translate(ch)));
Chris@16:     }
Chris@16: 
Chris@16:     template<typename Traits>
Chris@16:     bool test(char_type ch, Traits const &tr, mpl::true_) const
Chris@16:     {
Chris@16:         BOOST_ASSERT(this->icase_);
Chris@16:         return this->bset_.test(tr.hash(tr.translate_nocase(ch)));
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16: 
Chris@16:     // Make sure all sub-expressions being merged have the same case-sensitivity
Chris@16:     bool test_icase_(bool icase)
Chris@16:     {
Chris@16:         std::size_t count = this->bset_.count();
Chris@16: 
Chris@16:         if(256 == count)
Chris@16:         {
Chris@16:             return false; // all set already, nothing to do
Chris@16:         }
Chris@16:         else if(0 != count && this->icase_ != icase)
Chris@16:         {
Chris@16:             this->set_all(); // icase mismatch! set all and bail
Chris@16:             return false;
Chris@16:         }
Chris@16: 
Chris@16:         this->icase_ = icase;
Chris@16:         return true;
Chris@16:     }
Chris@16: 
Chris@16:     bool icase_;
Chris@16:     std::bitset<256> bset_;
Chris@16: };
Chris@16: 
Chris@16: }}} // namespace boost::xpressive::detail
Chris@16: 
Chris@101: #if defined(_MSC_VER)
Chris@16: # pragma warning(pop)
Chris@16: #endif
Chris@16: 
Chris@16: #endif