| /*============================================================================= |
| Copyright (c) 2001-2014 Joel de Guzman |
| |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| ==============================================================================*/ |
| #if !defined(BOOST_SPIRIT_X3_DETAIL_RULE_JAN_08_2012_0326PM) |
| #define BOOST_SPIRIT_X3_DETAIL_RULE_JAN_08_2012_0326PM |
| |
| #include <boost/core/ignore_unused.hpp> |
| #include <boost/spirit/home/x3/auxiliary/guard.hpp> |
| #include <boost/spirit/home/x3/core/parser.hpp> |
| #include <boost/spirit/home/x3/core/skip_over.hpp> |
| #include <boost/spirit/home/x3/directive/expect.hpp> |
| #include <boost/spirit/home/x3/support/utility/sfinae.hpp> |
| #include <boost/spirit/home/x3/nonterminal/detail/transform_attribute.hpp> |
| #include <boost/utility/addressof.hpp> |
| |
| #if defined(BOOST_SPIRIT_X3_DEBUG) |
| #include <boost/spirit/home/x3/nonterminal/simple_trace.hpp> |
| #endif |
| |
| #include <type_traits> |
| |
| namespace boost { namespace spirit { namespace x3 |
| { |
| template <typename ID> |
| struct identity; |
| |
| template <typename ID, typename Attribute = unused_type, bool force_attribute = false> |
| struct rule; |
| |
| struct parse_pass_context_tag; |
| |
| namespace detail |
| { |
| template <typename ID> |
| struct rule_id {}; |
| |
| // we use this so we can detect if the default parse_rule |
| // is the being called. |
| struct default_parse_rule_result |
| { |
| default_parse_rule_result(bool r) |
| : r(r) {} |
| operator bool() const { return r; } |
| bool r; |
| }; |
| } |
| |
| // default parse_rule implementation |
| template <typename ID, typename Iterator |
| , typename Context, typename ActualAttribute> |
| inline detail::default_parse_rule_result |
| parse_rule( |
| detail::rule_id<ID> |
| , Iterator& first, Iterator const& last |
| , Context const& context, ActualAttribute& attr); |
| }}} |
| |
| namespace boost { namespace spirit { namespace x3 { namespace detail |
| { |
| #if defined(BOOST_SPIRIT_X3_DEBUG) |
| template <typename Iterator, typename Attribute> |
| struct context_debug |
| { |
| context_debug( |
| char const* rule_name |
| , Iterator const& first, Iterator const& last |
| , Attribute const& attr |
| , bool const& ok_parse //was parse successful? |
| ) |
| : ok_parse(ok_parse), rule_name(rule_name) |
| , first(first), last(last) |
| , attr(attr) |
| , f(detail::get_simple_trace()) |
| { |
| f(first, last, attr, pre_parse, rule_name); |
| } |
| |
| ~context_debug() |
| { |
| auto status = ok_parse ? successful_parse : failed_parse ; |
| f(first, last, attr, status, rule_name); |
| } |
| |
| bool const& ok_parse; |
| char const* rule_name; |
| Iterator const& first; |
| Iterator const& last; |
| Attribute const& attr; |
| detail::simple_trace_type& f; |
| }; |
| #endif |
| |
| template <typename ID, typename Iterator, typename Context, typename Enable = void> |
| struct has_on_error : mpl::false_ {}; |
| |
| template <typename ID, typename Iterator, typename Context> |
| struct has_on_error<ID, Iterator, Context, |
| typename disable_if_substitution_failure< |
| decltype( |
| std::declval<ID>().on_error( |
| std::declval<Iterator&>() |
| , std::declval<Iterator>() |
| , std::declval<expectation_failure<Iterator>>() |
| , std::declval<Context>() |
| ) |
| )>::type |
| > |
| : mpl::true_ |
| {}; |
| |
| template <typename ID, typename Iterator, typename Attribute, typename Context, typename Enable = void> |
| struct has_on_success : mpl::false_ {}; |
| |
| template <typename ID, typename Iterator, typename Attribute, typename Context> |
| struct has_on_success<ID, Iterator, Context, Attribute, |
| typename disable_if_substitution_failure< |
| decltype( |
| std::declval<ID>().on_success( |
| std::declval<Iterator&>() |
| , std::declval<Iterator>() |
| , std::declval<Attribute&>() |
| , std::declval<Context>() |
| ) |
| )>::type |
| > |
| : mpl::true_ |
| {}; |
| |
| template <typename ID> |
| struct make_id |
| { |
| typedef identity<ID> type; |
| }; |
| |
| template <typename ID> |
| struct make_id<identity<ID>> |
| { |
| typedef identity<ID> type; |
| }; |
| |
| template <typename ID, typename RHS, typename Context> |
| Context const& |
| make_rule_context(RHS const& /* rhs */, Context const& context |
| , mpl::false_ /* is_default_parse_rule */) |
| { |
| return context; |
| } |
| |
| template <typename ID, typename RHS, typename Context> |
| auto make_rule_context(RHS const& rhs, Context const& context |
| , mpl::true_ /* is_default_parse_rule */ ) |
| { |
| return make_unique_context<ID>(rhs, context); |
| } |
| |
| template <typename Attribute, typename ID, bool skip_definition_injection = false> |
| struct rule_parser |
| { |
| template <typename Iterator, typename Context, typename ActualAttribute> |
| static bool call_on_success( |
| Iterator& /* first */, Iterator const& /* last */ |
| , Context const& /* context */, ActualAttribute& /* attr */ |
| , mpl::false_ /* No on_success handler */ ) |
| { |
| return true; |
| } |
| |
| template <typename Iterator, typename Context, typename ActualAttribute> |
| static bool call_on_success( |
| Iterator& first, Iterator const& last |
| , Context const& context, ActualAttribute& attr |
| , mpl::true_ /* Has on_success handler */) |
| { |
| bool pass = true; |
| ID().on_success( |
| first |
| , last |
| , attr |
| , make_context<parse_pass_context_tag>(pass, context) |
| ); |
| return pass; |
| } |
| |
| template <typename RHS, typename Iterator, typename Context |
| , typename RContext, typename ActualAttribute> |
| static bool parse_rhs_main( |
| RHS const& rhs |
| , Iterator& first, Iterator const& last |
| , Context const& context, RContext& rcontext, ActualAttribute& attr |
| , mpl::false_) |
| { |
| // see if the user has a BOOST_SPIRIT_DEFINE for this rule |
| typedef |
| decltype(parse_rule( |
| detail::rule_id<ID>{}, first, last |
| , make_unique_context<ID>(rhs, context), std::declval<Attribute&>())) |
| parse_rule_result; |
| |
| // If there is no BOOST_SPIRIT_DEFINE for this rule, |
| // we'll make a context for this rule tagged by its ID |
| // so we can extract the rule later on in the default |
| // (generic) parse_rule function. |
| typedef |
| is_same<parse_rule_result, default_parse_rule_result> |
| is_default_parse_rule; |
| |
| Iterator i = first; |
| bool r = rhs.parse( |
| i |
| , last |
| , make_rule_context<ID>(rhs, context, std::conditional_t<skip_definition_injection, mpl::false_, is_default_parse_rule>()) |
| , rcontext |
| , attr |
| ); |
| |
| if (r) |
| { |
| auto first_ = first; |
| x3::skip_over(first_, last, context); |
| r = call_on_success(first_, i, context, attr |
| , has_on_success<ID, Iterator, Context, ActualAttribute>()); |
| } |
| |
| if (r) |
| first = i; |
| return r; |
| } |
| |
| template <typename RHS, typename Iterator, typename Context |
| , typename RContext, typename ActualAttribute> |
| static bool parse_rhs_main( |
| RHS const& rhs |
| , Iterator& first, Iterator const& last |
| , Context const& context, RContext& rcontext, ActualAttribute& attr |
| , mpl::true_ /* on_error is found */) |
| { |
| for (;;) |
| { |
| try |
| { |
| return parse_rhs_main( |
| rhs, first, last, context, rcontext, attr, mpl::false_()); |
| } |
| catch (expectation_failure<Iterator> const& x) |
| { |
| switch (ID().on_error(first, last, x, context)) |
| { |
| case error_handler_result::fail: |
| return false; |
| case error_handler_result::retry: |
| continue; |
| case error_handler_result::accept: |
| return true; |
| case error_handler_result::rethrow: |
| throw; |
| } |
| } |
| } |
| } |
| |
| template <typename RHS, typename Iterator |
| , typename Context, typename RContext, typename ActualAttribute> |
| static bool parse_rhs_main( |
| RHS const& rhs |
| , Iterator& first, Iterator const& last |
| , Context const& context, RContext& rcontext, ActualAttribute& attr) |
| { |
| return parse_rhs_main( |
| rhs, first, last, context, rcontext, attr |
| , has_on_error<ID, Iterator, Context>() |
| ); |
| } |
| |
| template <typename RHS, typename Iterator |
| , typename Context, typename RContext, typename ActualAttribute> |
| static bool parse_rhs( |
| RHS const& rhs |
| , Iterator& first, Iterator const& last |
| , Context const& context, RContext& rcontext, ActualAttribute& attr |
| , mpl::false_) |
| { |
| return parse_rhs_main(rhs, first, last, context, rcontext, attr); |
| } |
| |
| template <typename RHS, typename Iterator |
| , typename Context, typename RContext, typename ActualAttribute> |
| static bool parse_rhs( |
| RHS const& rhs |
| , Iterator& first, Iterator const& last |
| , Context const& context, RContext& rcontext, ActualAttribute& /* attr */ |
| , mpl::true_) |
| { |
| return parse_rhs_main(rhs, first, last, context, rcontext, unused); |
| } |
| |
| template <typename RHS, typename Iterator, typename Context |
| , typename ActualAttribute, typename ExplicitAttrPropagation> |
| static bool call_rule_definition( |
| RHS const& rhs |
| , char const* rule_name |
| , Iterator& first, Iterator const& last |
| , Context const& context, ActualAttribute& attr |
| , ExplicitAttrPropagation) |
| { |
| boost::ignore_unused(rule_name); |
| |
| // do down-stream transformation, provides attribute for |
| // rhs parser |
| typedef traits::transform_attribute< |
| ActualAttribute, Attribute, parser_id> |
| transform; |
| |
| typedef typename transform::type transform_attr; |
| transform_attr attr_ = transform::pre(attr); |
| |
| bool ok_parse |
| //Creates a place to hold the result of parse_rhs |
| //called inside the following scope. |
| ; |
| { |
| // Create a scope to cause the dbg variable below (within |
| // the #if...#endif) to call it's DTOR before any |
| // modifications are made to the attribute, attr_ passed |
| // to parse_rhs (such as might be done in |
| // transform::post when, for example, |
| // ActualAttribute is a recursive variant). |
| #if defined(BOOST_SPIRIT_X3_DEBUG) |
| context_debug<Iterator, transform_attr> |
| dbg(rule_name, first, last, attr_, ok_parse); |
| #endif |
| ok_parse = parse_rhs(rhs, first, last, context, attr_, attr_ |
| , mpl::bool_ |
| < ( RHS::has_action |
| && !ExplicitAttrPropagation::value |
| ) |
| >() |
| ); |
| } |
| if (ok_parse) |
| { |
| // do up-stream transformation, this integrates the results |
| // back into the original attribute value, if appropriate |
| transform::post(attr, std::forward<transform_attr>(attr_)); |
| } |
| return ok_parse; |
| } |
| }; |
| }}}} |
| |
| #endif |
