1 // Copyright (c) 2001-2011 Hartmut Kaiser 2 // 3 // Distributed under the Boost Software License, Version 1.0. (See accompanying 4 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 5 6 #if !defined(BOOST_SPIRIT_LEX_STATIC_LEXER_FEB_10_2008_0753PM) 7 #define BOOST_SPIRIT_LEX_STATIC_LEXER_FEB_10_2008_0753PM 8 9 #if defined(_MSC_VER) 10 #pragma once 11 #endif 12 13 #include <boost/spirit/home/lex/lexer/lexertl/token.hpp> 14 #include <boost/spirit/home/lex/lexer/lexertl/functor.hpp> 15 #include <boost/spirit/home/lex/lexer/lexertl/static_functor_data.hpp> 16 #include <boost/spirit/home/lex/lexer/lexertl/iterator.hpp> 17 #include <boost/spirit/home/lex/lexer/lexertl/static_version.hpp> 18 #if defined(BOOST_SPIRIT_DEBUG) 19 #include <boost/spirit/home/support/detail/lexer/debug.hpp> 20 #endif 21 22 namespace boost { namespace spirit { namespace lex { namespace lexertl 23 { 24 /////////////////////////////////////////////////////////////////////////// 25 // forward declaration 26 /////////////////////////////////////////////////////////////////////////// 27 namespace static_ 28 { 29 struct lexer; 30 } 31 32 /////////////////////////////////////////////////////////////////////////// 33 // 34 // Every lexer type to be used as a lexer for Spirit has to conform to 35 // the following public interface: 36 // 37 // typedefs: 38 // iterator_type The type of the iterator exposed by this lexer. 39 // token_type The type of the tokens returned from the exposed 40 // iterators. 41 // 42 // functions: 43 // default constructor 44 // Since lexers are instantiated as base classes 45 // only it might be a good idea to make this 46 // constructor protected. 47 // begin, end Return a pair of iterators, when dereferenced 48 // returning the sequence of tokens recognized in 49 // the input stream given as the parameters to the 50 // begin() function. 51 // add_token Should add the definition of a token to be 52 // recognized by this lexer. 53 // clear Should delete all current token definitions 54 // associated with the given state of this lexer 55 // object. 56 // 57 // template parameters: 58 // Token The type of the tokens to be returned from the 59 // exposed token iterator. 60 // LexerTables See explanations below. 61 // Iterator The type of the iterator used to access the 62 // underlying character stream. 63 // Functor The type of the InputPolicy to use to instantiate 64 // the multi_pass iterator type to be used as the 65 // token iterator (returned from begin()/end()). 66 // 67 // Additionally, this implementation of a static lexer has a template 68 // parameter LexerTables allowing to customize the static lexer tables 69 // to be used. The LexerTables is expected to be a type exposing 70 // the following functions: 71 // 72 // static std::size_t const state_count() 73 // 74 // This function needs toreturn the number of lexer states 75 // contained in the table returned from the state_names() 76 // function. 77 // 78 // static char const* const* state_names() 79 // 80 // This function needs to return a pointer to a table of 81 // names of all lexer states. The table needs to have as 82 // much entries as the state_count() function returns 83 // 84 // template<typename Iterator> 85 // std::size_t next(std::size_t &start_state_, Iterator const& start_ 86 // , Iterator &start_token_, Iterator const& end_ 87 // , std::size_t& unique_id_); 88 // 89 // This function is expected to return the next matched 90 // token from the underlying input stream. 91 // 92 /////////////////////////////////////////////////////////////////////////// 93 94 /////////////////////////////////////////////////////////////////////////// 95 // 96 // The static_lexer class is a implementation of a Spirit.Lex 97 // lexer on top of Ben Hanson's lexertl library (For more information 98 // about lexertl go here: http://www.benhanson.net/lexertl.html). 99 // 100 // This class is designed to be used in conjunction with a generated, 101 // static lexer. For more information see the documentation (The Static 102 // Lexer Model). 103 // 104 // This class is supposed to be used as the first and only template 105 // parameter while instantiating instances of a lex::lexer class. 106 // 107 /////////////////////////////////////////////////////////////////////////// 108 template <typename Token = token<> 109 , typename LexerTables = static_::lexer 110 , typename Iterator = typename Token::iterator_type 111 , typename Functor = functor<Token, detail::static_data, Iterator> > 112 class static_lexer 113 { 114 private: true_boost::spirit::lex::lexertl::static_lexer::dummy115 struct dummy { void true_() {} }; 116 typedef void (dummy::*safe_bool)(); 117 118 public: 119 // object is always valid operator safe_bool() const120 operator safe_bool() const { return &dummy::true_; } 121 122 typedef typename boost::detail::iterator_traits<Iterator>::value_type 123 char_type; 124 typedef std::basic_string<char_type> string_type; 125 126 // Every lexer type to be used as a lexer for Spirit has to conform to 127 // a public interface 128 typedef Token token_type; 129 typedef typename Token::id_type id_type; 130 typedef iterator<Functor> iterator_type; 131 132 private: 133 // this type is purely used for the iterator_type construction below 134 struct iterator_data_type 135 { 136 typedef typename Functor::next_token_functor next_token_functor; 137 typedef typename Functor::semantic_actions_type semantic_actions_type; 138 typedef typename Functor::get_state_name_type get_state_name_type; 139 iterator_data_typeboost::spirit::lex::lexertl::static_lexer::iterator_data_type140 iterator_data_type(next_token_functor next 141 , semantic_actions_type const& actions 142 , get_state_name_type get_state_name, std::size_t num_states 143 , bool bol) 144 : next_(next), actions_(actions), get_state_name_(get_state_name) 145 , num_states_(num_states), bol_(bol) 146 {} 147 148 next_token_functor next_; 149 semantic_actions_type const& actions_; 150 get_state_name_type get_state_name_; 151 std::size_t num_states_; 152 bool bol_; 153 154 private: 155 // silence MSVC warning C4512: assignment operator could not be generated 156 iterator_data_type& operator= (iterator_data_type const&); 157 }; 158 159 typedef LexerTables tables_type; 160 161 // The following static assertion fires if the referenced static lexer 162 // tables are generated by a different static lexer version as used for 163 // the current compilation unit. Please regenerate your static lexer 164 // tables before trying to create a static_lexer<> instance. 165 BOOST_SPIRIT_ASSERT_MSG( 166 tables_type::static_version == SPIRIT_STATIC_LEXER_VERSION 167 , incompatible_static_lexer_version, (LexerTables)); 168 169 public: 170 // Return the start iterator usable for iterating over the generated 171 // tokens, the generated function next_token(...) is called to match 172 // the next token from the input. 173 template <typename Iterator_> begin(Iterator_ & first,Iterator_ const & last,char_type const * initial_state=0) const174 iterator_type begin(Iterator_& first, Iterator_ const& last 175 , char_type const* initial_state = 0) const 176 { 177 iterator_data_type iterator_data( 178 &tables_type::template next<Iterator_>, actions_ 179 , &tables_type::state_name, tables_type::state_count() 180 , tables_type::supports_bol 181 ); 182 return iterator_type(iterator_data, first, last, initial_state); 183 } 184 185 // Return the end iterator usable to stop iterating over the generated 186 // tokens. end() const187 iterator_type end() const 188 { 189 return iterator_type(); 190 } 191 192 protected: 193 // Lexer instances can be created by means of a derived class only. static_lexer(unsigned int)194 static_lexer(unsigned int) : unique_id_(0) {} 195 196 public: 197 // interface for token definition management add_token(char_type const *,char_type,std::size_t,char_type const *)198 std::size_t add_token (char_type const*, char_type, std::size_t 199 , char_type const*) 200 { 201 return unique_id_++; 202 } add_token(char_type const *,string_type const &,std::size_t,char_type const *)203 std::size_t add_token (char_type const*, string_type const& 204 , std::size_t, char_type const*) 205 { 206 return unique_id_++; 207 } 208 209 // interface for pattern definition management add_pattern(char_type const *,string_type const &,string_type const &)210 void add_pattern (char_type const*, string_type const& 211 , string_type const&) {} 212 clear(char_type const *)213 void clear(char_type const*) {} 214 add_state(char_type const * state)215 std::size_t add_state(char_type const* state) 216 { 217 return detail::get_state_id(state, &tables_type::state_name 218 , tables_type::state_count()); 219 } initial_state() const220 string_type initial_state() const 221 { 222 return tables_type::state_name(0); 223 } 224 225 // register a semantic action with the given id 226 template <typename F> add_action(id_type unique_id,std::size_t state,F act)227 void add_action(id_type unique_id, std::size_t state, F act) 228 { 229 typedef typename Functor::wrap_action_type wrapper_type; 230 actions_.add_action(unique_id, state, wrapper_type::call(act)); 231 } 232 init_dfa(bool minimize=false) const233 bool init_dfa(bool minimize = false) const { return true; } 234 235 private: 236 typename Functor::semantic_actions_type actions_; 237 std::size_t unique_id_; 238 }; 239 240 /////////////////////////////////////////////////////////////////////////// 241 // 242 // The static_actor_lexer class is another implementation of a 243 // Spirit.Lex lexer on top of Ben Hanson's lexertl library as outlined 244 // above (For more information about lexertl go here: 245 // http://www.benhanson.net/lexertl.html). 246 // 247 // Just as the static_lexer class it is meant to be used with 248 // a statically generated lexer as outlined above. 249 // 250 // The only difference to the static_lexer class above is that 251 // token_def definitions may have semantic (lexer) actions attached while 252 // being defined: 253 // 254 // int w; 255 // token_def<> word = "[^ \t\n]+"; 256 // self = word[++ref(w)]; // see example: word_count_lexer 257 // 258 // This class is supposed to be used as the first and only template 259 // parameter while instantiating instances of a lex::lexer class. 260 // 261 /////////////////////////////////////////////////////////////////////////// 262 template <typename Token = token<> 263 , typename LexerTables = static_::lexer 264 , typename Iterator = typename Token::iterator_type 265 , typename Functor 266 = functor<Token, detail::static_data, Iterator, mpl::true_> > 267 class static_actor_lexer 268 : public static_lexer<Token, LexerTables, Iterator, Functor> 269 { 270 protected: 271 // Lexer instances can be created by means of a derived class only. static_actor_lexer(unsigned int flags)272 static_actor_lexer(unsigned int flags) 273 : static_lexer<Token, LexerTables, Iterator, Functor>(flags) 274 {} 275 }; 276 277 }}}} 278 279 #endif 280