/*=============================================================================
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Copyright (arg) 2001-2014 Joel de Guzman
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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=============================================================================*/
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#if !defined(BOOST_SPIRIT_X3_ACTION_JANUARY_07_2007_1128AM)
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#define BOOST_SPIRIT_X3_ACTION_JANUARY_07_2007_1128AM
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#include <boost/spirit/home/x3/support/context.hpp>
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#include <boost/spirit/home/x3/support/traits/attribute_of.hpp>
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#include <boost/spirit/home/x3/core/call.hpp>
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#include <boost/spirit/home/x3/nonterminal/detail/transform_attribute.hpp>
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#include <boost/range/iterator_range_core.hpp>
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namespace boost { namespace spirit { namespace x3
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{
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struct raw_attribute_type;
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struct parse_pass_context_tag;
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template <typename Context>
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inline bool& _pass(Context const& context)
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{
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return x3::get<parse_pass_context_tag>(context);
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}
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template <typename Subject, typename Action>
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struct action : unary_parser<Subject, action<Subject, Action>>
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{
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typedef unary_parser<Subject, action<Subject, Action>> base_type;
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static bool const is_pass_through_unary = true;
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static bool const has_action = true;
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constexpr action(Subject const& subject, Action f)
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: base_type(subject), f(f) {}
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template <typename Iterator, typename Context, typename RuleContext, typename Attribute>
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bool call_action(
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Iterator& first, Iterator const& last
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, Context const& context, RuleContext& rcontext, Attribute& attr) const
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{
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bool pass = true;
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auto action_context = make_context<parse_pass_context_tag>(pass, context);
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call(f, first, last, action_context, rcontext, attr);
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return pass;
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}
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template <typename Iterator, typename Context
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, typename RuleContext, typename Attribute>
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bool parse_main(Iterator& first, Iterator const& last
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, Context const& context, RuleContext& rcontext, Attribute& attr) const
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{
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Iterator save = first;
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if (this->subject.parse(first, last, context, rcontext, attr))
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{
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if (call_action(first, last, context, rcontext, attr))
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return true;
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// reset iterators if semantic action failed the match
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// retrospectively
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first = save;
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}
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return false;
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}
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// attr==raw_attribute_type, action wants iterator_range (see raw.hpp)
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template <typename Iterator, typename Context, typename RuleContext>
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bool parse_main(Iterator& first, Iterator const& last
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, Context const& context, RuleContext& rcontext, raw_attribute_type&) const
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{
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boost::iterator_range<Iterator> rng;
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// synthesize the attribute since one is not supplied
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return parse_main(first, last, context, rcontext, rng);
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}
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// attr==unused, action wants attribute
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template <typename Iterator, typename Context, typename RuleContext>
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bool parse(Iterator& first, Iterator const& last
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, Context const& context, RuleContext& rcontext, unused_type) const
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{
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typedef typename
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traits::attribute_of<action<Subject, Action>, Context>::type
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attribute_type;
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// synthesize the attribute since one is not supplied
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attribute_type attr{};
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return parse_main(first, last, context, rcontext, attr);
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}
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// main parse function
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template <typename Iterator, typename Context
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, typename RuleContext, typename Attribute>
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bool parse(Iterator& first, Iterator const& last
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, Context const& context, RuleContext& rcontext, Attribute& attr) const
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{
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return parse_main(first, last, context, rcontext, attr);
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}
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Action f;
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};
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template <typename P, typename Action>
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constexpr action<typename extension::as_parser<P>::value_type, Action>
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operator/(P const& p, Action f)
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{
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return { as_parser(p), f };
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}
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}}}
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#endif
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