1 /////////////////////////////////////////////////////////////////////////////// 2 // peeker.hpp 3 // 4 // Copyright 2008 Eric Niebler. Distributed under the Boost 5 // Software License, Version 1.0. (See accompanying file 6 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 7 8 #ifndef BOOST_XPRESSIVE_DETAIL_CORE_PEEKER_HPP_EAN_10_04_2005 9 #define BOOST_XPRESSIVE_DETAIL_CORE_PEEKER_HPP_EAN_10_04_2005 10 11 // MS compatible compilers support #pragma once 12 #if defined(_MSC_VER) 13 # pragma once 14 #endif 15 16 #include <string> 17 #include <typeinfo> 18 #include <boost/assert.hpp> 19 #include <boost/mpl/bool.hpp> 20 #include <boost/mpl/assert.hpp> 21 #include <boost/mpl/size_t.hpp> 22 #include <boost/mpl/equal_to.hpp> 23 #include <boost/utility/enable_if.hpp> 24 #include <boost/xpressive/detail/detail_fwd.hpp> 25 #include <boost/xpressive/detail/core/matchers.hpp> 26 #include <boost/xpressive/detail/utility/hash_peek_bitset.hpp> 27 #include <boost/xpressive/detail/utility/never_true.hpp> 28 #include <boost/xpressive/detail/utility/algorithm.hpp> 29 30 namespace boost { namespace xpressive { namespace detail 31 { 32 33 /////////////////////////////////////////////////////////////////////////////// 34 // peeker_string 35 // 36 template<typename Char> 37 struct peeker_string 38 { 39 Char const *begin_; 40 Char const *end_; 41 bool icase_; 42 }; 43 44 /////////////////////////////////////////////////////////////////////////////// 45 // char_sink 46 // 47 template<typename Traits, bool ICase> 48 struct char_sink 49 { 50 typedef typename Traits::char_type char_type; 51 char_sinkboost::xpressive::detail::char_sink52 char_sink(hash_peek_bitset<char_type> &bset, Traits const &tr) 53 : bset_(bset) 54 , traits_(tr) 55 {} 56 operator ()boost::xpressive::detail::char_sink57 void operator()(char_type ch) const 58 { 59 this->bset_.set_char(ch, ICase, this->traits_); 60 } 61 62 hash_peek_bitset<char_type> &bset_; 63 Traits const &traits_; 64 private: 65 char_sink &operator =(char_sink const &); 66 }; 67 68 /////////////////////////////////////////////////////////////////////////////// 69 // xpression_peeker 70 // 71 template<typename Char> 72 struct xpression_peeker 73 { 74 template<typename Traits> xpression_peekerboost::xpressive::detail::xpression_peeker75 xpression_peeker(hash_peek_bitset<Char> &bset, Traits const &tr, bool has_backrefs = false) 76 : bset_(bset) 77 , str_() 78 , line_start_(false) 79 , traits_(0) 80 , traits_type_(0) 81 , leading_simple_repeat_(0) 82 , has_backrefs_(has_backrefs) 83 { 84 this->set_traits(tr); 85 } 86 87 /////////////////////////////////////////////////////////////////////////////// 88 // accessors get_stringboost::xpressive::detail::xpression_peeker89 peeker_string<Char> const &get_string() const 90 { 91 return this->str_; 92 } 93 line_startboost::xpressive::detail::xpression_peeker94 bool line_start() const 95 { 96 return this->line_start_; 97 } 98 leading_simple_repeatboost::xpressive::detail::xpression_peeker99 bool leading_simple_repeat() const 100 { 101 return 0 < this->leading_simple_repeat_; 102 } 103 bitsetboost::xpressive::detail::xpression_peeker104 hash_peek_bitset<Char> const &bitset() const 105 { 106 return this->bset_; 107 } 108 109 /////////////////////////////////////////////////////////////////////////////// 110 // modifiers failboost::xpressive::detail::xpression_peeker111 void fail() 112 { 113 this->bset_.set_all(); 114 } 115 116 template<typename Matcher> acceptboost::xpressive::detail::xpression_peeker117 mpl::false_ accept(Matcher const &) 118 { 119 this->fail(); 120 return mpl::false_(); 121 } 122 acceptboost::xpressive::detail::xpression_peeker123 mpl::true_ accept(mark_begin_matcher const &) 124 { 125 if(this->has_backrefs_) 126 { 127 --this->leading_simple_repeat_; 128 } 129 return mpl::true_(); 130 } 131 acceptboost::xpressive::detail::xpression_peeker132 mpl::true_ accept(repeat_begin_matcher const &) 133 { 134 --this->leading_simple_repeat_; 135 return mpl::true_(); 136 } 137 138 template<typename Traits> acceptboost::xpressive::detail::xpression_peeker139 mpl::true_ accept(assert_bol_matcher<Traits> const &) 140 { 141 this->line_start_ = true; 142 return mpl::true_(); 143 } 144 145 template<typename Traits, typename ICase> acceptboost::xpressive::detail::xpression_peeker146 mpl::false_ accept(literal_matcher<Traits, ICase, mpl::false_> const &xpr) 147 { 148 this->bset_.set_char(xpr.ch_, ICase(), this->get_traits_<Traits>()); 149 return mpl::false_(); 150 } 151 152 template<typename Traits, typename ICase> acceptboost::xpressive::detail::xpression_peeker153 mpl::false_ accept(string_matcher<Traits, ICase> const &xpr) 154 { 155 this->bset_.set_char(xpr.str_[0], ICase(), this->get_traits_<Traits>()); 156 this->str_.begin_ = detail::data_begin(xpr.str_); 157 this->str_.end_ = detail::data_end(xpr.str_); 158 this->str_.icase_ = ICase::value; 159 return mpl::false_(); 160 } 161 162 template<typename Alternates, typename Traits> acceptboost::xpressive::detail::xpression_peeker163 mpl::false_ accept(alternate_matcher<Alternates, Traits> const &xpr) 164 { 165 BOOST_ASSERT(0 != xpr.bset_.count()); 166 this->bset_.set_bitset(xpr.bset_); 167 return mpl::false_(); 168 } 169 170 template<typename Matcher, typename Traits, typename ICase> acceptboost::xpressive::detail::xpression_peeker171 mpl::false_ accept(attr_matcher<Matcher, Traits, ICase> const &xpr) 172 { 173 xpr.sym_.peek(char_sink<Traits, ICase::value>(this->bset_, this->get_traits_<Traits>())); 174 return mpl::false_(); 175 } 176 177 template<typename Xpr, typename Greedy> acceptboost::xpressive::detail::xpression_peeker178 mpl::false_ accept(optional_matcher<Xpr, Greedy> const &) 179 { 180 this->fail(); // a union of xpr and next 181 return mpl::false_(); 182 } 183 184 template<typename Xpr, typename Greedy> acceptboost::xpressive::detail::xpression_peeker185 mpl::false_ accept(optional_mark_matcher<Xpr, Greedy> const &) 186 { 187 this->fail(); // a union of xpr and next 188 return mpl::false_(); 189 } 190 191 //template<typename Xpr, typename Greedy> 192 //mpl::true_ accept(optional_matcher<Xpr, Greedy> const &xpr) 193 //{ 194 // xpr.xpr_.peek(*this); // a union of xpr and next 195 // return mpl::true_(); 196 //} 197 198 //template<typename Xpr, typename Greedy> 199 //mpl::true_ accept(optional_mark_matcher<Xpr, Greedy> const &xpr) 200 //{ 201 // xpr.xpr_.peek(*this); // a union of xpr and next 202 // return mpl::true_(); 203 //} 204 205 template<typename Traits> acceptboost::xpressive::detail::xpression_peeker206 mpl::false_ accept(posix_charset_matcher<Traits> const &xpr) 207 { 208 this->bset_.set_class(xpr.mask_, xpr.not_, this->get_traits_<Traits>()); 209 return mpl::false_(); 210 } 211 212 template<typename ICase, typename Traits> 213 typename enable_if<is_narrow_char<typename Traits::char_type>, mpl::false_>::type acceptboost::xpressive::detail::xpression_peeker214 accept(charset_matcher<Traits, ICase, basic_chset<Char> > const &xpr) 215 { 216 BOOST_ASSERT(0 != xpr.charset_.base().count()); 217 this->bset_.set_charset(xpr.charset_, ICase()); 218 return mpl::false_(); 219 } 220 221 template<typename Traits, typename ICase> acceptboost::xpressive::detail::xpression_peeker222 mpl::false_ accept(range_matcher<Traits, ICase> const &xpr) 223 { 224 this->bset_.set_range(xpr.ch_min_, xpr.ch_max_, xpr.not_, ICase(), this->get_traits_<Traits>()); 225 return mpl::false_(); 226 } 227 228 template<typename Xpr, typename Greedy> acceptboost::xpressive::detail::xpression_peeker229 mpl::false_ accept(simple_repeat_matcher<Xpr, Greedy> const &xpr) 230 { 231 if(Greedy() && 1U == xpr.width_) 232 { 233 ++this->leading_simple_repeat_; 234 xpr.leading_ = this->leading_simple_repeat(); 235 } 236 0 != xpr.min_ ? xpr.xpr_.peek(*this) : this->fail(); // could be a union of xpr and next 237 return mpl::false_(); 238 } 239 240 template<typename Xpr> acceptboost::xpressive::detail::xpression_peeker241 mpl::false_ accept(keeper_matcher<Xpr> const &xpr) 242 { 243 xpr.xpr_.peek(*this); 244 return mpl::false_(); 245 } 246 247 template<typename Traits> set_traitsboost::xpressive::detail::xpression_peeker248 void set_traits(Traits const &tr) 249 { 250 if(0 == this->traits_) 251 { 252 this->traits_ = &tr; 253 this->traits_type_ = &typeid(Traits); 254 } 255 else if(*this->traits_type_ != typeid(Traits) || this->get_traits_<Traits>() != tr) 256 { 257 this->fail(); // traits mis-match! set all and bail 258 } 259 } 260 261 private: 262 xpression_peeker(xpression_peeker const &); 263 xpression_peeker &operator =(xpression_peeker const &); 264 265 template<typename Traits> get_traits_boost::xpressive::detail::xpression_peeker266 Traits const &get_traits_() const 267 { 268 BOOST_ASSERT(!!(*this->traits_type_ == typeid(Traits))); 269 return *static_cast<Traits const *>(this->traits_); 270 } 271 272 hash_peek_bitset<Char> &bset_; 273 peeker_string<Char> str_; 274 bool str_icase_; 275 bool line_start_; 276 void const *traits_; 277 std::type_info const *traits_type_; 278 int leading_simple_repeat_; 279 bool has_backrefs_; 280 }; 281 282 }}} // namespace boost::xpressive::detail 283 284 #endif 285