1 /*============================================================================= 2 Copyright (c) 2001-2014 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_X3_LEXEME_MARCH_24_2007_0802AM) 8 #define BOOST_SPIRIT_X3_LEXEME_MARCH_24_2007_0802AM 9 10 #include <boost/spirit/home/x3/support/context.hpp> 11 #include <boost/spirit/home/x3/support/unused.hpp> 12 #include <boost/spirit/home/x3/core/skip_over.hpp> 13 #include <boost/spirit/home/x3/core/parser.hpp> 14 #include <boost/type_traits/remove_reference.hpp> 15 #include <boost/utility/enable_if.hpp> 16 17 namespace boost { namespace spirit { namespace x3 18 { 19 template <typename Subject> 20 struct lexeme_directive : unary_parser<Subject, lexeme_directive<Subject>> 21 { 22 typedef unary_parser<Subject, lexeme_directive<Subject> > base_type; 23 static bool const is_pass_through_unary = true; 24 static bool const handles_container = Subject::handles_container; 25 lexeme_directiveboost::spirit::x3::lexeme_directive26 lexeme_directive(Subject const& subject) 27 : base_type(subject) {} 28 29 template <typename Iterator, typename Context 30 , typename RContext, typename Attribute> 31 typename enable_if<has_skipper<Context>, bool>::type parseboost::spirit::x3::lexeme_directive32 parse(Iterator& first, Iterator const& last 33 , Context const& context, RContext& rcontext, Attribute& attr) const 34 { 35 x3::skip_over(first, last, context); 36 auto const& skipper = x3::get<skipper_tag>(context); 37 38 typedef unused_skipper< 39 typename remove_reference<decltype(skipper)>::type> 40 unused_skipper_type; 41 unused_skipper_type unused_skipper(skipper); 42 43 return this->subject.parse( 44 first, last 45 , make_context<skipper_tag>(unused_skipper, context) 46 , rcontext 47 , attr); 48 } 49 50 template <typename Iterator, typename Context 51 , typename RContext, typename Attribute> 52 typename disable_if<has_skipper<Context>, bool>::type parseboost::spirit::x3::lexeme_directive53 parse(Iterator& first, Iterator const& last 54 , Context const& context, RContext& rcontext, Attribute& attr) const 55 { 56 // no need to pre-skip if skipper is unused 57 return this->subject.parse( 58 first, last 59 , context 60 , rcontext 61 , attr); 62 } 63 }; 64 65 struct lexeme_gen 66 { 67 template <typename Subject> 68 lexeme_directive<typename extension::as_parser<Subject>::value_type> operator []boost::spirit::x3::lexeme_gen69 operator[](Subject const& subject) const 70 { 71 return { as_parser(subject) }; 72 } 73 }; 74 75 auto const lexeme = lexeme_gen{}; 76 }}} 77 78 #endif 79