| /*============================================================================= |
| 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_EPS_MARCH_23_2007_0454PM) |
| #define BOOST_SPIRIT_X3_EPS_MARCH_23_2007_0454PM |
| |
| #if defined(_MSC_VER) |
| #pragma once |
| #endif |
| |
| #include <boost/spirit/home/x3/core/skip_over.hpp> |
| #include <boost/spirit/home/x3/core/parser.hpp> |
| #include <boost/spirit/home/x3/support/unused.hpp> |
| |
| namespace boost { namespace spirit { namespace x3 |
| { |
| struct rule_context_tag; |
| |
| struct semantic_predicate : parser<semantic_predicate> |
| { |
| typedef unused_type attribute_type; |
| static bool const has_attribute = false; |
| |
| semantic_predicate(bool predicate) |
| : predicate(predicate) {} |
| |
| template <typename Iterator, typename Context, typename Attribute> |
| bool parse(Iterator& first, Iterator const& last |
| , Context const& context, unused_type, Attribute&) const |
| { |
| x3::skip_over(first, last, context); |
| return predicate; |
| } |
| |
| bool predicate; |
| }; |
| |
| template <typename F> |
| struct lazy_semantic_predicate : parser<lazy_semantic_predicate<F>> |
| { |
| typedef unused_type attribute_type; |
| static bool const has_attribute = false; |
| |
| lazy_semantic_predicate(F f) |
| : f(f) {} |
| |
| template <typename Iterator, typename Context, typename Attribute> |
| bool parse(Iterator& first, Iterator const& last |
| , Context const& context, unused_type, Attribute& attr) const |
| { |
| x3::skip_over(first, last, context); |
| return f(x3::get<rule_context_tag>(context)); |
| } |
| |
| F f; |
| }; |
| |
| struct eps_parser : parser<eps_parser> |
| { |
| typedef unused_type attribute_type; |
| static bool const has_attribute = false; |
| |
| template <typename Iterator, typename Context |
| , typename RuleContext, typename Attribute> |
| bool parse(Iterator& first, Iterator const& last |
| , Context const& context, RuleContext&, Attribute&) const |
| { |
| x3::skip_over(first, last, context); |
| return true; |
| } |
| |
| semantic_predicate |
| operator()(bool predicate) const |
| { |
| return semantic_predicate(predicate); |
| } |
| |
| template <typename F> |
| lazy_semantic_predicate<F> |
| operator()(F f) const |
| { |
| return lazy_semantic_predicate<F>(f); |
| } |
| }; |
| |
| eps_parser const eps = eps_parser(); |
| }}} |
| |
| #endif |