/src/contrib/boost/spirit/home/lex/lexer/lexertl/static_lexer.hpp
C++ Header | 278 lines | 127 code | 28 blank | 123 comment | 1 complexity | e4101029c3beb6e3c7f7e0254650329c MD5 | raw file
1// Copyright (c) 2001-2010 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 22namespace 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: 115 struct dummy { void true_() {}; }; 116 typedef void (dummy::*safe_bool)(); 117 118 public: 119 // object is always valid 120 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; 139 140 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_> 174 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. 187 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. 194 static_lexer(unsigned int) : unique_id_(0) {} 195 196 public: 197 // interface for token definition management 198 std::size_t add_token (char_type const*, char_type, std::size_t) 199 { 200 return unique_id_++; 201 } 202 std::size_t add_token (char_type const*, string_type const& 203 , std::size_t) 204 { 205 return unique_id_++; 206 } 207 208 // interface for pattern definition management 209 void add_pattern (char_type const*, string_type const& 210 , string_type const&) {} 211 212 void clear(char_type const*) {} 213 214 std::size_t add_state(char_type const* state) 215 { 216 return detail::get_state_id(state, &tables_type::state_name 217 , tables_type::state_count()); 218 } 219 string_type initial_state() const 220 { 221 return tables_type::state_name(0); 222 } 223 224 // register a semantic action with the given id 225 template <typename F> 226 void add_action(id_type unique_id, std::size_t state, F act) 227 { 228 typedef typename Functor::wrap_action_type wrapper_type; 229 actions_.add_action(unique_id, state, wrapper_type::call(act)); 230 } 231 232 bool init_dfa(bool minimize = false) const { return true; } 233 234 private: 235 typename Functor::semantic_actions_type actions_; 236 std::size_t unique_id_; 237 }; 238 239 /////////////////////////////////////////////////////////////////////////// 240 // 241 // The static_actor_lexer class is another implementation of a 242 // Spirit.Lex lexer on top of Ben Hanson's lexertl library as outlined 243 // above (For more information about lexertl go here: 244 // http://www.benhanson.net/lexertl.html). 245 // 246 // Just as the static_lexer class it is meant to be used with 247 // a statically generated lexer as outlined above. 248 // 249 // The only difference to the static_lexer class above is that 250 // token_def definitions may have semantic (lexer) actions attached while 251 // being defined: 252 // 253 // int w; 254 // token_def<> word = "[^ \t\n]+"; 255 // self = word[++ref(w)]; // see example: word_count_lexer 256 // 257 // This class is supposed to be used as the first and only template 258 // parameter while instantiating instances of a lex::lexer class. 259 // 260 /////////////////////////////////////////////////////////////////////////// 261 template <typename Token = token<> 262 , typename LexerTables = static_::lexer 263 , typename Iterator = typename Token::iterator_type 264 , typename Functor 265 = functor<Token, detail::static_data, Iterator, mpl::true_> > 266 class static_actor_lexer 267 : public static_lexer<Token, LexerTables, Iterator, Functor> 268 { 269 protected: 270 // Lexer instances can be created by means of a derived class only. 271 static_actor_lexer(unsigned int flags) 272 : static_lexer<Token, LexerTables, Iterator, Functor>(flags) 273 {} 274 }; 275 276}}}} 277 278#endif