Chris@102: /*=============================================================================
Chris@102:     Copyright (c) 2014 Joel de Guzman
Chris@102: 
Chris@102:     Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@102:     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@102: =============================================================================*/
Chris@102: #if !defined(SPIRIT_X3_WITH_MAY_02_2014_0749AM)
Chris@102: #define SPIRIT_X3_WITH_MAY_02_2014_0749AM
Chris@102: 
Chris@102: #include <boost/spirit/home/x3/support/unused.hpp>
Chris@102: #include <boost/spirit/home/x3/core/parser.hpp>
Chris@102: 
Chris@102: namespace boost { namespace spirit { namespace x3
Chris@102: {
Chris@102:     ///////////////////////////////////////////////////////////////////////////
Chris@102:     // with directive injects a value into the context prior to parsing.
Chris@102:     ///////////////////////////////////////////////////////////////////////////
Chris@102:     template <typename Subject, typename Derived, typename T>
Chris@102:     struct with_value_holder
Chris@102:       : unary_parser<Subject, Derived>
Chris@102:     {
Chris@102:         typedef unary_parser<Subject, Derived> base_type;
Chris@102:         mutable T val;
Chris@102:         with_value_holder(Subject const& subject, T const& val)
Chris@102:           : base_type(subject)
Chris@102:           , val(val) {}
Chris@102:     };
Chris@102:     
Chris@102:     template <typename Subject, typename Derived, typename T>
Chris@102:     struct with_value_holder<Subject, Derived, T const>
Chris@102:       : unary_parser<Subject, Derived>
Chris@102:     {
Chris@102:         typedef unary_parser<Subject, Derived> base_type;
Chris@102:         T val;
Chris@102:         with_value_holder(Subject const& subject, T const& val)
Chris@102:           : base_type(subject)
Chris@102:           , val(val) {}
Chris@102:     };
Chris@102: 
Chris@102:     template <typename Subject, typename ID, typename T>
Chris@102:     struct with_directive
Chris@102:       : with_value_holder<Subject, with_directive<Subject, ID, T>, T>
Chris@102:     {
Chris@102:         typedef with_value_holder<Subject, with_directive<Subject, ID, T>, T> base_type;
Chris@102:         static bool const is_pass_through_unary = true;
Chris@102:         static bool const handles_container = Subject::handles_container;
Chris@102: 
Chris@102:         typedef Subject subject_type;
Chris@102: 
Chris@102:         with_directive(Subject const& subject, T const& val)
Chris@102:           : base_type(subject, val) {}
Chris@102: 
Chris@102:         template <typename Iterator, typename Context
Chris@102:           , typename RContext, typename Attribute>
Chris@102:         bool parse(Iterator& first, Iterator const& last
Chris@102:           , Context const& context, RContext& rcontext, Attribute& attr) const
Chris@102:         {
Chris@102:             return this->subject.parse(
Chris@102:                 first, last
Chris@102:               , make_context<ID>(this->val, context)
Chris@102:               , rcontext
Chris@102:               , attr);
Chris@102:         }
Chris@102:     };
Chris@102:    
Chris@102:     template <typename ID, typename T, typename NextContext = unused_type>
Chris@102:     struct with_context
Chris@102:     {
Chris@102:         typedef context<ID, T, NextContext> type;
Chris@102:     };
Chris@102:     
Chris@102:     template <typename ID, typename T>
Chris@102:     struct with_context<ID, T, unused_type>
Chris@102:     {
Chris@102:         typedef context<ID, T> const type;
Chris@102:     };
Chris@102: 
Chris@102:     template <typename ID, typename T>
Chris@102:     struct with_gen
Chris@102:     {
Chris@102:         T& val;
Chris@102: 
Chris@102:         with_gen(T& val)
Chris@102:           : val(val) {}
Chris@102: 
Chris@102:         template <typename Subject>
Chris@102:         with_directive<typename extension::as_parser<Subject>::value_type, ID, T>
Chris@102:         operator[](Subject const& subject) const
Chris@102:         {
Chris@102:             return {as_parser(subject), val};
Chris@102:         }
Chris@102:     };
Chris@102: 
Chris@102:     template <typename ID, typename T>
Chris@102:     inline with_gen<ID, T> with(T& val)
Chris@102:     {
Chris@102:         return with_gen<ID, T>{val};
Chris@102:     }
Chris@102:     
Chris@102:     template <typename ID, typename T>
Chris@102:     inline with_gen<ID, T const> with(T const& val)
Chris@102:     {
Chris@102:         return with_gen<ID, T const>{val};
Chris@102:     }
Chris@102: }}}
Chris@102: 
Chris@102: #endif