/src/contrib/boost/spirit/home/lex/lexer/lexertl/semantic_action_data.hpp

  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_LEXER_SEMANTIC_ACTION_DATA_JUN_10_2009_0417PM)
  7#define BOOST_SPIRIT_LEX_LEXER_SEMANTIC_ACTION_DATA_JUN_10_2009_0417PM
  8
  9#if defined(_MSC_VER)
 10#pragma once
 11#endif
 12
 13#include <boost/spirit/home/lex/lexer/pass_flags.hpp>
 14#include <boost/mpl/bool.hpp>
 15#include <boost/function.hpp>
 16#include <vector>
 17
 18namespace boost { namespace spirit { namespace lex { namespace lexertl
 19{ 
 20    namespace detail
 21    {
 22        ///////////////////////////////////////////////////////////////////////
 23        template <typename Iterator, typename SupportsState, typename Data>
 24        struct semantic_actions;
 25
 26        // This specialization of semantic_actions will be used if the token
 27        // type (lexer definition) does not support states, which simplifies 
 28        // the data structures used to store the semantic action function 
 29        // objects.
 30        template <typename Iterator, typename Data>
 31        struct semantic_actions<Iterator, mpl::false_, Data>
 32        {
 33            typedef void functor_type(Iterator&, Iterator&
 34              , BOOST_SCOPED_ENUM(pass_flags)&, std::size_t&, Data&);
 35            typedef boost::function<functor_type> functor_wrapper_type;
 36
 37            // add a semantic action function object
 38            template <typename Idtype, typename F>
 39            void add_action(Idtype unique_id, std::size_t, F act) 
 40            {
 41                if (actions_.size() <= unique_id)
 42                    actions_.resize(unique_id + 1); 
 43
 44                actions_[unique_id] = act;
 45            }
 46
 47            // try to invoke a semantic action for the given token (unique_id)
 48            BOOST_SCOPED_ENUM(pass_flags) invoke_actions(std::size_t /*state*/
 49              , std::size_t& id, std::size_t unique_id, Iterator& end
 50              , Data& data) const
 51            {
 52                // if there is nothing to invoke, continue with 'match'
 53                if (unique_id >= actions_.size() || !actions_[unique_id]) 
 54                    return pass_flags::pass_normal;
 55
 56                // Note: all arguments might be changed by the invoked semantic 
 57                //       action
 58                BOOST_SCOPED_ENUM(pass_flags) match = pass_flags::pass_normal;
 59                actions_[unique_id](data.get_first(), end, match, id, data);
 60                return match;
 61            }
 62
 63            std::vector<functor_wrapper_type> actions_;
 64        }; 
 65
 66        // This specialization of semantic_actions will be used if the token
 67        // type (lexer definition) needs to support states, resulting in a more
 68        // complex data structure needed for storing the semantic action 
 69        // function objects.
 70        template <typename Iterator, typename Data>
 71        struct semantic_actions<Iterator, mpl::true_, Data>
 72        {
 73            typedef void functor_type(Iterator&, Iterator&
 74              , BOOST_SCOPED_ENUM(pass_flags)&, std::size_t&, Data&);
 75            typedef boost::function<functor_type> functor_wrapper_type;
 76
 77            // add a semantic action function object
 78            template <typename Idtype, typename F>
 79            void add_action(Idtype unique_id, std::size_t state, F act) 
 80            {
 81                if (actions_.size() <= state)
 82                    actions_.resize(state + 1); 
 83
 84                std::vector<functor_wrapper_type>& actions (actions_[state]);
 85                if (actions.size() <= unique_id)
 86                    actions.resize(unique_id + 1); 
 87
 88                actions[unique_id] = act;
 89            }
 90
 91            // try to invoke a semantic action for the given token (unique_id)
 92            BOOST_SCOPED_ENUM(pass_flags) invoke_actions(std::size_t state
 93              , std::size_t& id, std::size_t unique_id, Iterator& end
 94              , Data& data) const
 95            {
 96                // if there is no action defined for this state, return match
 97                if (state >= actions_.size())
 98                    return pass_flags::pass_normal;
 99
100                // if there is nothing to invoke, continue with 'match'
101                std::vector<functor_wrapper_type> const& actions = actions_[state];
102                if (unique_id >= actions.size() || !actions[unique_id]) 
103                    return pass_flags::pass_normal;
104
105                // Note: all arguments might be changed by the invoked semantic 
106                //       action
107                BOOST_SCOPED_ENUM(pass_flags) match = pass_flags::pass_normal;
108                actions[unique_id](data.get_first(), end, match, id, data);
109                return match;
110            }
111
112            std::vector<std::vector<functor_wrapper_type> > actions_;
113        }; 
114    }
115
116}}}}
117
118#endif