Chris@16: /*=============================================================================
Chris@16:     Copyright (c) 2001-2011 Joel de Guzman
Chris@16: 
Chris@16:     Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16:     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: ==============================================================================*/
Chris@16: #if !defined(BOOST_SPIRIT_LAZY_MARCH_27_2007_1002AM)
Chris@16: #define BOOST_SPIRIT_LAZY_MARCH_27_2007_1002AM
Chris@16: 
Chris@16: #if defined(_MSC_VER)
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/spirit/home/qi/domain.hpp>
Chris@16: #include <boost/spirit/home/qi/skip_over.hpp>
Chris@16: #include <boost/spirit/home/qi/meta_compiler.hpp>
Chris@16: #include <boost/spirit/home/qi/detail/attributes.hpp>
Chris@16: #include <boost/spirit/home/support/unused.hpp>
Chris@16: #include <boost/spirit/home/support/info.hpp>
Chris@16: #include <boost/spirit/home/support/lazy.hpp>
Chris@16: #include <boost/spirit/include/phoenix_core.hpp>
Chris@16: #include <boost/fusion/include/at.hpp>
Chris@16: #include <boost/utility/result_of.hpp>
Chris@16: #include <boost/type_traits/remove_reference.hpp>
Chris@16: #include <boost/mpl/not.hpp>
Chris@16: 
Chris@16: namespace boost { namespace spirit
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     // Enablers
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Eval>
Chris@16:     struct use_terminal<qi::domain, phoenix::actor<Eval> >  // enables phoenix actors
Chris@16:         : mpl::true_ {};
Chris@16: 
Chris@16:     // forward declaration
Chris@16:     template <typename Terminal, typename Actor, int Arity>
Chris@16:     struct lazy_terminal;
Chris@16: }}
Chris@16: 
Chris@16: namespace boost { namespace spirit { namespace qi
Chris@16: {
Chris@16:     using spirit::lazy;
Chris@16:     typedef modify<qi::domain> qi_modify;
Chris@16: 
Chris@16:     namespace detail
Chris@16:     {
Chris@16:         template <typename Parser, typename Iterator, typename Context
Chris@16:           , typename Skipper, typename Attribute>
Chris@16:         bool lazy_parse_impl(Parser const& p
Chris@16:           , Iterator& first, Iterator const& last
Chris@16:           , Context& context, Skipper const& skipper
Chris@16:           , Attribute& attr, mpl::false_)
Chris@16:         {
Chris@16:             return p.parse(first, last, context, skipper, attr);
Chris@16:         }
Chris@16: 
Chris@16:         template <typename Parser, typename Iterator, typename Context
Chris@16:           , typename Skipper, typename Attribute>
Chris@16:         bool lazy_parse_impl(Parser const& p
Chris@16:           , Iterator& first, Iterator const& last
Chris@16:           , Context& context, Skipper const& skipper
Chris@16:           , Attribute& /*attr*/, mpl::true_)
Chris@16:         {
Chris@16:             // If DeducedAuto is false (semantic actions is present), the
Chris@16:             // component's attribute is unused.
Chris@16:             return p.parse(first, last, context, skipper, unused);
Chris@16:         }
Chris@16: 
Chris@16:         template <typename Parser, typename Iterator, typename Context
Chris@16:           , typename Skipper, typename Attribute>
Chris@16:         bool lazy_parse_impl_main(Parser const& p
Chris@16:           , Iterator& first, Iterator const& last
Chris@16:           , Context& context, Skipper const& skipper
Chris@16:           , Attribute& attr)
Chris@16:         {
Chris@16:             // If DeducedAuto is true (no semantic action), we pass the parser's
Chris@16:             // attribute on to the component.
Chris@16:             typedef typename traits::has_semantic_action<Parser>::type auto_rule;
Chris@16:             return lazy_parse_impl(p, first, last, context, skipper, attr, auto_rule());
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     template <typename Function, typename Modifiers>
Chris@16:     struct lazy_parser : parser<lazy_parser<Function, Modifiers> >
Chris@16:     {
Chris@16:         template <typename Context, typename Iterator>
Chris@16:         struct attribute
Chris@16:         {
Chris@16:             typedef typename
Chris@16:                 boost::result_of<qi_modify(tag::lazy_eval, Modifiers)>::type
Chris@16:             modifier;
Chris@16: 
Chris@16:             typedef typename
Chris@16:                 remove_reference<
Chris@16:                     typename boost::result_of<Function(unused_type, Context)>::type
Chris@16:                 >::type
Chris@16:             expr_type;
Chris@16: 
Chris@16:             // If you got an error_invalid_expression error message here,
Chris@16:             // then the expression (expr_type) is not a valid spirit qi
Chris@16:             // expression.
Chris@16:             BOOST_SPIRIT_ASSERT_MATCH(qi::domain, expr_type);
Chris@16: 
Chris@16:             typedef typename
Chris@16:                 result_of::compile<qi::domain, expr_type, modifier>::type
Chris@16:             parser_type;
Chris@16: 
Chris@16:             typedef typename
Chris@16:                 traits::attribute_of<parser_type, Context, Iterator>::type
Chris@16:             type;
Chris@16:         };
Chris@16: 
Chris@16:         lazy_parser(Function const& function_, Modifiers const& modifiers_)
Chris@16:           : function(function_), modifiers(modifiers_) {}
Chris@16: 
Chris@16:         template <typename Iterator, typename Context
Chris@16:           , typename Skipper, typename Attribute>
Chris@16:         bool parse(Iterator& first, Iterator const& last
Chris@16:           , Context& context, Skipper const& skipper
Chris@16:           , Attribute& attr) const
Chris@16:         {
Chris@16:             return detail::lazy_parse_impl_main(
Chris@16:                   compile<qi::domain>(function(unused, context)
Chris@16:                 , qi_modify()(tag::lazy_eval(), modifiers))
Chris@16:                 , first, last, context, skipper, attr);
Chris@16:         }
Chris@16: 
Chris@16:         template <typename Context>
Chris@16:         info what(Context& context) const
Chris@16:         {
Chris@16:             return info("lazy"
Chris@16:               , compile<qi::domain>(function(unused, context)
Chris@16:                 , qi_modify()(tag::lazy_eval(), modifiers))
Chris@16:                     .what(context)
Chris@16:             );
Chris@16:         }
Chris@16: 
Chris@16:         Function function;
Chris@16:         Modifiers modifiers;
Chris@16:     };
Chris@16: 
Chris@16: 
Chris@16:     template <typename Function, typename Subject, typename Modifiers>
Chris@16:     struct lazy_directive
Chris@16:         : unary_parser<lazy_directive<Function, Subject, Modifiers> >
Chris@16:     {
Chris@16:         typedef Subject subject_type;
Chris@16: 
Chris@16:         template <typename Context, typename Iterator>
Chris@16:         struct attribute
Chris@16:         {
Chris@16:             typedef typename
Chris@16:                 boost::result_of<qi_modify(tag::lazy_eval, Modifiers)>::type
Chris@16:             modifier;
Chris@16: 
Chris@16:             typedef typename
Chris@16:                 remove_reference<
Chris@16:                     typename boost::result_of<Function(unused_type, Context)>::type
Chris@16:                 >::type
Chris@16:             directive_expr_type;
Chris@16: 
Chris@16:             typedef typename
Chris@16:                 proto::result_of::make_expr<
Chris@16:                     proto::tag::subscript
Chris@16:                   , directive_expr_type
Chris@16:                   , Subject
Chris@16:                 >::type
Chris@16:             expr_type;
Chris@16: 
Chris@16:             // If you got an error_invalid_expression error message here,
Chris@16:             // then the expression (expr_type) is not a valid spirit qi
Chris@16:             // expression.
Chris@16:             BOOST_SPIRIT_ASSERT_MATCH(qi::domain, expr_type);
Chris@16: 
Chris@16:             typedef typename
Chris@16:                 result_of::compile<qi::domain, expr_type, modifier>::type
Chris@16:             parser_type;
Chris@16: 
Chris@16:             typedef typename
Chris@16:                 traits::attribute_of<parser_type, Context, Iterator>::type
Chris@16:             type;
Chris@16:         };
Chris@16: 
Chris@16:         lazy_directive(
Chris@16:             Function const& function_
Chris@16:           , Subject const& subject_
Chris@16:           , Modifiers const& modifiers_)
Chris@16:           : function(function_), subject(subject_), modifiers(modifiers_) {}
Chris@16: 
Chris@16:         template <typename Iterator, typename Context
Chris@16:           , typename Skipper, typename Attribute>
Chris@16:         bool parse(Iterator& first, Iterator const& last
Chris@16:           , Context& context, Skipper const& skipper
Chris@16:           , Attribute& attr) const
Chris@16:         {
Chris@16:             return detail::lazy_parse_impl_main(compile<qi::domain>(
Chris@16:                 proto::make_expr<proto::tag::subscript>(
Chris@16:                     function(unused, context)
Chris@16:                   , subject)
Chris@16:                 , qi_modify()(tag::lazy_eval(), modifiers))
Chris@16:                 , first, last, context, skipper, attr);
Chris@16:         }
Chris@16: 
Chris@16:         template <typename Context>
Chris@16:         info what(Context& context) const
Chris@16:         {
Chris@16:             return info("lazy-directive"
Chris@16:               , compile<qi::domain>(
Chris@16:                     proto::make_expr<proto::tag::subscript>(
Chris@16:                         function(unused, context)
Chris@16:                       , subject
Chris@16:                     ), qi_modify()(tag::lazy_eval(), modifiers))
Chris@16:                     .what(context)
Chris@16:             );
Chris@16:         }
Chris@16: 
Chris@16:         Function function;
Chris@16:         Subject subject;
Chris@16:         Modifiers modifiers;
Chris@16:     };
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     // Parser generators: make_xxx function (objects)
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Eval, typename Modifiers>
Chris@16:     struct make_primitive<phoenix::actor<Eval>, Modifiers>
Chris@16:     {
Chris@16:         typedef lazy_parser<phoenix::actor<Eval>, Modifiers> result_type;
Chris@16:         result_type operator()(phoenix::actor<Eval> const& f
Chris@16:           , Modifiers const& modifiers) const
Chris@16:         {
Chris@16:             return result_type(f, modifiers);
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     template <typename Terminal, typename Actor, int Arity, typename Modifiers>
Chris@16:     struct make_primitive<lazy_terminal<Terminal, Actor, Arity>, Modifiers>
Chris@16:     {
Chris@16:         typedef lazy_parser<Actor, Modifiers> result_type;
Chris@16:         result_type operator()(
Chris@16:             lazy_terminal<Terminal, Actor, Arity> const& lt
Chris@16:           , Modifiers const& modifiers) const
Chris@16:         {
Chris@16:             return result_type(lt.actor, modifiers);
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     template <typename Terminal, typename Actor, int Arity, typename Subject, typename Modifiers>
Chris@16:     struct make_directive<lazy_terminal<Terminal, Actor, Arity>, Subject, Modifiers>
Chris@16:     {
Chris@16:         typedef lazy_directive<Actor, Subject, Modifiers> result_type;
Chris@16:         result_type operator()(
Chris@16:             lazy_terminal<Terminal, Actor, Arity> const& lt
Chris@16:           , Subject const& subject, Modifiers const& modifiers) const
Chris@16:         {
Chris@16:             return result_type(lt.actor, subject, modifiers);
Chris@16:         }
Chris@16:     };
Chris@16: }}}
Chris@16: 
Chris@16: namespace boost { namespace spirit { namespace traits
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Actor, typename Modifiers, typename Attribute
Chris@16:       , typename Context, typename Iterator>
Chris@16:     struct handles_container<
Chris@16:         qi::lazy_parser<Actor, Modifiers>, Attribute, Context, Iterator>
Chris@16:       : handles_container<
Chris@16:           typename qi::lazy_parser<Actor, Modifiers>::template
Chris@16:               attribute<Context, Iterator>::parser_type
Chris@16:         , Attribute, Context, Iterator>
Chris@16:     {};
Chris@16: 
Chris@16:     template <typename Subject, typename Actor, typename Modifiers
Chris@16:       , typename Attribute, typename Context, typename Iterator>
Chris@16:     struct handles_container<
Chris@16:         qi::lazy_directive<Actor, Subject, Modifiers>, Attribute
Chris@16:       , Context, Iterator>
Chris@16:       : handles_container<
Chris@16:           typename qi::lazy_directive<Actor, Subject, Modifiers>::template
Chris@16:               attribute<Context, Iterator>::parser_type
Chris@16:         , Attribute, Context, Iterator>
Chris@16:     {};
Chris@16: }}}
Chris@16: 
Chris@16: #endif