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(SPIRIT_EXPECT_FUNCTION_APR_29_2007_0558PM)
Chris@16: #define SPIRIT_EXPECT_FUNCTION_APR_29_2007_0558PM
Chris@16: 
Chris@16: #if defined(_MSC_VER)
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/spirit/home/support/unused.hpp>
Chris@16: #include <boost/spirit/home/support/multi_pass_wrapper.hpp>
Chris@16: #include <boost/throw_exception.hpp>
Chris@16: 
Chris@16: namespace boost { namespace spirit { namespace qi { namespace detail
Chris@16: {
Chris@16:     template <
Chris@16:         typename Iterator, typename Context
Chris@16:       , typename Skipper, typename Exception>
Chris@16:     struct expect_function
Chris@16:     {
Chris@16:         typedef Iterator iterator_type;
Chris@16:         typedef Context context_type;
Chris@16: 
Chris@16:         expect_function(
Chris@16:             Iterator& first_, Iterator const& last_
Chris@16:           , Context& context_, Skipper const& skipper_)
Chris@16:           : first(first_)
Chris@16:           , last(last_)
Chris@16:           , context(context_)
Chris@16:           , skipper(skipper_)
Chris@16:           , is_first(true)
Chris@16:         {
Chris@16:         }
Chris@16: 
Chris@16:         template <typename Component, typename Attribute>
Chris@16:         bool operator()(Component const& component, Attribute& attr) const
Chris@16:         {
Chris@16:             // if this is not the first component in the expect chain we 
Chris@16:             // need to flush any multi_pass iterator we might be acting on
Chris@16:             if (!is_first)
Chris@16:                 spirit::traits::clear_queue(first);
Chris@16: 
Chris@16:             // if we are testing the first component in the sequence,
Chris@16:             // return true if the parser fails, if this is not the first
Chris@16:             // component, throw exception if the parser fails
Chris@16:             if (!component.parse(first, last, context, skipper, attr))
Chris@16:             {
Chris@16:                 if (is_first)
Chris@16:                 {
Chris@16:                     is_first = false;
Chris@16:                     return true;        // true means the match failed
Chris@16:                 }
Chris@16:                 boost::throw_exception(Exception(first, last, component.what(context)));
Chris@16: #if defined(BOOST_NO_EXCEPTIONS)
Chris@16:                 return true;            // for systems not supporting exceptions
Chris@16: #endif
Chris@16:             }
Chris@16:             is_first = false;
Chris@16:             return false;
Chris@16:         }
Chris@16: 
Chris@16:         template <typename Component>
Chris@16:         bool operator()(Component const& component) const
Chris@16:         {
Chris@16:             // if this is not the first component in the expect chain we 
Chris@16:             // need to flush any multi_pass iterator we might be acting on
Chris@16:             if (!is_first)
Chris@16:                 spirit::traits::clear_queue(first);
Chris@16: 
Chris@16:             // if we are testing the first component in the sequence,
Chris@16:             // return true if the parser fails, if this not the first
Chris@16:             // component, throw exception if the parser fails
Chris@16:             if (!component.parse(first, last, context, skipper, unused))
Chris@16:             {
Chris@16:                 if (is_first)
Chris@16:                 {
Chris@16:                     is_first = false;
Chris@16:                     return true;
Chris@16:                 }
Chris@16:                 boost::throw_exception(Exception(first, last, component.what(context)));
Chris@16: #if defined(BOOST_NO_EXCEPTIONS)
Chris@16:                 return false;   // for systems not supporting exceptions
Chris@16: #endif
Chris@16:             }
Chris@16:             is_first = false;
Chris@16:             return false;
Chris@16:         }
Chris@16: 
Chris@16:         Iterator& first;
Chris@16:         Iterator const& last;
Chris@16:         Context& context;
Chris@16:         Skipper const& skipper;
Chris@16:         mutable bool is_first;
Chris@16: 
Chris@16:     private:
Chris@16:         // silence MSVC warning C4512: assignment operator could not be generated
Chris@16:         expect_function& operator= (expect_function const&);
Chris@16:     };
Chris@16: }}}}
Chris@16: 
Chris@16: #endif