1 /*============================================================================= 2 Copyright (c) 2001-2011 Joel de Guzman 3 4 Distributed under the Boost Software License, Version 1.0. (See accompanying 5 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 6 ==============================================================================*/ 7 #if !defined(BOOST_SPIRIT_PARSER_BINDER_DECEMBER_05_2008_0516_PM) 8 #define BOOST_SPIRIT_PARSER_BINDER_DECEMBER_05_2008_0516_PM 9 10 #if defined(_MSC_VER) 11 #pragma once 12 #endif 13 14 #include <boost/fusion/include/at.hpp> 15 #include <boost/mpl/bool.hpp> 16 #include <boost/spirit/home/support/has_semantic_action.hpp> 17 18 namespace boost { namespace spirit { namespace qi { namespace detail 19 { 20 // parser_binder for plain rules 21 template <typename Parser, typename Auto> 22 struct parser_binder 23 { parser_binderboost::spirit::qi::detail::parser_binder24 parser_binder(Parser const& p_) 25 : p(p_) {} 26 27 template <typename Iterator, typename Skipper, typename Context> callboost::spirit::qi::detail::parser_binder28 bool call(Iterator& first, Iterator const& last 29 , Context& context, Skipper const& skipper, mpl::true_) const 30 { 31 // If DeducedAuto is false (semantic actions is present), the 32 // component's attribute is unused. 33 return p.parse(first, last, context, skipper, unused); 34 } 35 36 template <typename Iterator, typename Skipper, typename Context> callboost::spirit::qi::detail::parser_binder37 bool call(Iterator& first, Iterator const& last 38 , Context& context, Skipper const& skipper, mpl::false_) const 39 { 40 // If DeducedAuto is true (no semantic action), we pass the rule's 41 // attribute on to the component. 42 return p.parse(first, last, context, skipper 43 , fusion::at_c<0>(context.attributes)); 44 } 45 46 template <typename Iterator, typename Skipper, typename Context> operator ()boost::spirit::qi::detail::parser_binder47 bool operator()( 48 Iterator& first, Iterator const& last 49 , Context& context, Skipper const& skipper) const 50 { 51 // If Auto is false, we need to deduce whether to apply auto rule 52 typedef typename traits::has_semantic_action<Parser>::type auto_rule; 53 return call(first, last, context, skipper, auto_rule()); 54 } 55 56 Parser p; 57 }; 58 59 // parser_binder for auto rules 60 template <typename Parser> 61 struct parser_binder<Parser, mpl::true_> 62 { parser_binderboost::spirit::qi::detail::parser_binder63 parser_binder(Parser const& p_) 64 : p(p_) {} 65 66 template <typename Iterator, typename Skipper, typename Context> operator ()boost::spirit::qi::detail::parser_binder67 bool operator()( 68 Iterator& first, Iterator const& last 69 , Context& context, Skipper const& skipper) const 70 { 71 // If Auto is true, we pass the rule's attribute on to the component. 72 return p.parse(first, last, context, skipper 73 , fusion::at_c<0>(context.attributes)); 74 } 75 76 Parser p; 77 }; 78 79 template <typename Auto, typename Parser> 80 inline parser_binder<Parser, Auto> bind_parser(Parser const & p)81 bind_parser(Parser const& p) 82 { 83 return parser_binder<Parser, Auto>(p); 84 } 85 }}}} 86 87 #endif 88