| // Copyright (c) 2001-2009 Hartmut Kaiser |
| // |
| // Distributed under 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) |
| |
| #if !defined(BOOST_SPIRIT_LEX_LEXERTL_LEXER_MAR_17_2007_0139PM) |
| #define BOOST_SPIRIT_LEX_LEXERTL_LEXER_MAR_17_2007_0139PM |
| |
| #if defined(_MSC_VER) && (_MSC_VER >= 1020) |
| #pragma once // MS compatible compilers support #pragma once |
| #endif |
| |
| #include <iosfwd> |
| |
| #include <boost/spirit/home/support/safe_bool.hpp> |
| #include <boost/spirit/home/support/detail/lexer/generator.hpp> |
| #include <boost/spirit/home/support/detail/lexer/rules.hpp> |
| #include <boost/spirit/home/support/detail/lexer/consts.hpp> |
| #include <boost/spirit/home/lex/lexer/lexer_fwd.hpp> |
| #include <boost/spirit/home/lex/lexer/lexertl/lexertl_token.hpp> |
| #include <boost/spirit/home/lex/lexer/lexertl/lexertl_functor.hpp> |
| #include <boost/spirit/home/lex/lexer/lexertl/lexertl_iterator.hpp> |
| #if defined(BOOST_SPIRIT_LEXERTL_DEBUG) |
| #include <boost/spirit/home/support/detail/lexer/debug.hpp> |
| #endif |
| |
| namespace boost { namespace spirit { namespace lex |
| { |
| /////////////////////////////////////////////////////////////////////////// |
| namespace detail |
| { |
| /////////////////////////////////////////////////////////////////////// |
| // The must_escape function checks if the given character value needs |
| // to be preceded by a backslash character to disable its special |
| // meaning in the context of a regular expression |
| /////////////////////////////////////////////////////////////////////// |
| template <typename Char> |
| inline bool must_escape(Char c) |
| { |
| // FIXME: more needed? |
| switch (c) { |
| case '+': case '/': case '*': case '?': |
| case '|': |
| case '(': case ')': |
| case '[': case ']': |
| case '{': case '}': |
| case '.': |
| case '^': case '$': |
| case '\\': |
| case '"': |
| return true; |
| |
| default: |
| break; |
| } |
| return false; |
| } |
| |
| /////////////////////////////////////////////////////////////////////// |
| // The escape function returns the string representation of the given |
| // character value, possibly escaped with a backslash character, to |
| // allow it being safely used in a regular expression definition. |
| /////////////////////////////////////////////////////////////////////// |
| template <typename Char> |
| inline std::basic_string<Char> escape(Char ch) |
| { |
| std::basic_string<Char> result(1, ch); |
| if (detail::must_escape(ch)) |
| { |
| typedef typename std::basic_string<Char>::size_type size_type; |
| result.insert((size_type)0, 1, '\\'); |
| } |
| return result; |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // lexertl_token_set |
| /////////////////////////////////////////////////////////////////////////// |
| template <typename Token, typename Iterator = typename Token::iterator_type> |
| class lexertl_token_set |
| { |
| protected: |
| typedef typename |
| boost::detail::iterator_traits<Iterator>::value_type |
| char_type; |
| typedef std::basic_string<char_type> string_type; |
| |
| public: |
| typedef Token token_type; |
| typedef typename Token::id_type id_type; |
| |
| // interface for token definition management |
| void add_token (char_type const* state, string_type const& tokendef, |
| std::size_t token_id) |
| { |
| rules.add(state, tokendef, token_id, state); |
| } |
| |
| // interface for pattern definition management |
| void add_pattern (char_type const* state, string_type const& name, |
| string_type const& patterndef) |
| { |
| add_state(state); |
| rules.add_macro(name.c_str(), patterndef); |
| } |
| |
| boost::lexer::rules const& get_rules() const { return rules; } |
| |
| void clear() { rules.clear(); } |
| |
| std::size_t add_state(char_type const* state) |
| { |
| rules.add_state(state); |
| return rules.state(state); |
| } |
| string_type initial_state() const |
| { |
| return string_type(rules.initial()); |
| } |
| |
| private: |
| boost::lexer::basic_rules<char_type> rules; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////// |
| template <typename Lexer> |
| bool generate_static(Lexer const& lex, std::ostream& os, char const* name); |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // |
| // Every lexer type to be used as a lexer for Spirit has to conform to |
| // the following public interface: |
| // |
| // typedefs: |
| // iterator_type The type of the iterator exposed by this lexer. |
| // token_type The type of the tokens returned from the exposed |
| // iterators. |
| // token_set The type of the token set representing a lexer |
| // state. |
| // |
| // functions: |
| // default constructor |
| // Since lexers are instantiated as base classes |
| // only it might be a good idea to make this |
| // constructor protected. |
| // begin, end Return a pair of iterators, when dereferenced |
| // returning the sequence of tokens recognized in |
| // the input stream given as the parameters to the |
| // begin() function. |
| // add_token Should add the definition of a token to be |
| // recognized by this lexer. |
| // clear Should delete all current token definitions |
| // associated with the given state of this lexer |
| // object. |
| // |
| // template parameters: |
| // Iterator The type of the iterator used to access the |
| // underlying character stream. |
| // Token The type of the tokens to be returned from the |
| // exposed token iterator. |
| // Functor The type of the InputPolicy to use to instantiate |
| // the multi_pass iterator type to be used as the |
| // token iterator (returned from begin()/end()). |
| // TokenSet The type of the token set to use in conjunction |
| // with this lexer type. This is used for the |
| // token_set typedef described above only. |
| // |
| /////////////////////////////////////////////////////////////////////////// |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // |
| // The lexertl_lexer class is a implementation of a Spirit.Lex lexer on |
| // top of Ben Hanson's lexertl library as outlined above (For more |
| // information about lexertl go here: http://www.benhanson.net/lexertl.html). |
| // |
| // This class is supposed to be used as the first and only template |
| // parameter while instantiating instances of a lex::lexer_def class. |
| // |
| /////////////////////////////////////////////////////////////////////////// |
| template < |
| typename Token = lexertl_token<>, |
| typename Iterator = typename Token::iterator_type, |
| typename Functor = lexertl_functor<Token, Iterator, mpl::false_>, |
| typename TokenSet = token_set<lexertl_token_set<Token, Iterator> > |
| > |
| class lexertl_lexer |
| : public safe_bool<lexertl_lexer<Token, Iterator, Functor, TokenSet> > |
| { |
| public: |
| // operator_bool() is needed for the safe_bool base class |
| bool operator_bool() const { return initialized_dfa; } |
| |
| typedef typename |
| boost::detail::iterator_traits<Iterator>::value_type |
| char_type; |
| typedef std::basic_string<char_type> string_type; |
| |
| // Every lexer type to be used as a lexer for Spirit has to conform to |
| // a public interface . |
| typedef Token token_type; |
| typedef typename Token::id_type id_type; |
| typedef TokenSet token_set; |
| typedef lexertl_iterator<Functor> iterator_type; |
| |
| private: |
| // this type is purely used for the iterator_type construction below |
| struct iterator_data_type { |
| boost::lexer::basic_state_machine<char_type> const& state_machine_; |
| boost::lexer::basic_rules<char_type> const& rules_; |
| typename Functor::semantic_actions_type const& actions_; |
| }; |
| |
| public: |
| // Return the start iterator usable for iterating over the generated |
| // tokens. |
| iterator_type begin(Iterator& first, Iterator const& last) const |
| { |
| if (!init_dfa()) |
| return iterator_type(); |
| |
| iterator_data_type iterator_data = { state_machine, rules, actions }; |
| return iterator_type(iterator_data, first, last); |
| } |
| |
| // Return the end iterator usable to stop iterating over the generated |
| // tokens. |
| iterator_type end() const |
| { |
| return iterator_type(); |
| } |
| |
| protected: |
| // Lexer instances can be created by means of a derived class only. |
| lexertl_lexer() |
| : initialized_dfa(false) |
| { |
| } |
| |
| public: |
| // interface for token definition management |
| void add_token (char_type const* state, string_type const& tokendef, |
| std::size_t token_id) |
| { |
| add_state(state); |
| rules.add(state, tokendef, token_id, state); |
| initialized_dfa = false; |
| } |
| void add_token(char_type const* state, token_set& tokset) |
| { |
| add_state(state); |
| rules.add(state, tokset.get_rules()); |
| initialized_dfa = false; |
| } |
| |
| // interface for pattern definition management |
| void add_pattern (char_type const* state, string_type const& name, |
| string_type const& patterndef) |
| { |
| add_state(state); |
| rules.add_macro(name.c_str(), patterndef); |
| initialized_dfa = false; |
| } |
| |
| void clear(char_type const* state) |
| { |
| std::size_t s = rules.state(state); |
| if (boost::lexer::npos != s) |
| rules.clear(state); |
| initialized_dfa = false; |
| } |
| std::size_t add_state(char_type const* state) |
| { |
| std::size_t stateid = rules.state(state); |
| if (boost::lexer::npos == stateid) { |
| rules.add_state(state); |
| stateid = rules.state(state); |
| initialized_dfa = false; |
| } |
| return stateid; |
| } |
| string_type initial_state() const |
| { |
| return string_type(rules.initial()); |
| } |
| |
| // Register a semantic action with the given id |
| template <typename F> |
| void add_action(std::size_t id, F act) |
| { |
| // If you get compilation errors below stating value_type not being |
| // a member of boost::fusion::unused_type, then you are probably |
| // using semantic actions in your token definition without |
| // the lexertl_actor_lexer being specified as the base class |
| // (instead of the lexertl_lexer class). |
| typedef |
| typename Functor::semantic_actions_type::value_type |
| value_type; |
| |
| typedef typename Functor::wrap_action_type wrapper_type; |
| |
| actions.insert(value_type(id, wrapper_type::call(act))); |
| } |
| |
| bool init_dfa() const |
| { |
| if (!initialized_dfa) { |
| state_machine.clear(); |
| try { |
| typedef boost::lexer::basic_generator<char_type> generator; |
| generator::build (rules, state_machine); |
| generator::minimise (state_machine); |
| |
| #if defined(BOOST_SPIRIT_LEXERTL_DEBUG) |
| boost::lexer::debug::dump(state_machine, std::cerr); |
| #endif |
| } |
| catch (std::runtime_error const&) { |
| return false; |
| } |
| initialized_dfa = true; |
| } |
| return true; |
| } |
| |
| private: |
| mutable boost::lexer::basic_state_machine<char_type> state_machine; |
| boost::lexer::basic_rules<char_type> rules; |
| typename Functor::semantic_actions_type actions; |
| mutable bool initialized_dfa; |
| |
| template <typename Lexer> |
| friend bool generate_static(Lexer const&, std::ostream&, char const*); |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // |
| // The lexertl_actor_lexer class is another implementation of a Spirit.Lex |
| // lexer on top of Ben Hanson's lexertl library as outlined above (For |
| // more information about lexertl go here: |
| // http://www.benhanson.net/lexertl.html). |
| // |
| // The only difference to the lexertl_lexer class above is that token_def |
| // definitions may have semantic (lexer) actions attached while being |
| // defined: |
| // |
| // int w; |
| // token_def word = "[^ \t\n]+"; |
| // self = word[++ref(w)]; // see example: word_count_lexer |
| // |
| // This class is supposed to be used as the first and only template |
| // parameter while instantiating instances of a lex::lexer_def class. |
| // |
| /////////////////////////////////////////////////////////////////////////// |
| template < |
| typename Token = lexertl_token<>, |
| typename Iterator = typename Token::iterator_type, |
| typename Functor = lexertl_functor<Token, Iterator, mpl::true_>, |
| typename TokenSet = token_set<lexertl_token_set<Token, Iterator> > |
| > |
| class lexertl_actor_lexer |
| : public lexertl_lexer<Token, Iterator, Functor, TokenSet> |
| { |
| protected: |
| // Lexer instances can be created by means of a derived class only. |
| lexertl_actor_lexer() {} |
| }; |
| |
| }}} |
| |
| #endif |