Chris@16: /*=============================================================================
Chris@16:     Boost.Wave: A Standard compliant C++ preprocessor library
Chris@16: 
Chris@16:     Definition of the unput queue iterator
Chris@16:     
Chris@16:     http://www.boost.org/
Chris@16: 
Chris@16:     Copyright (c) 2001-2012 Hartmut Kaiser. Distributed under the Boost
Chris@16:     Software License, Version 1.0. (See accompanying file
Chris@16:     LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: =============================================================================*/
Chris@16: #if !defined(UNPUT_QUEUE_ITERATOR_HPP_76DA23D0_4893_4AD5_ABCC_6CED7CFB89BC_INCLUDED)
Chris@16: #define UNPUT_QUEUE_ITERATOR_HPP_76DA23D0_4893_4AD5_ABCC_6CED7CFB89BC_INCLUDED
Chris@16: 
Chris@16: #include <list>
Chris@16: 
Chris@16: #include <boost/assert.hpp>
Chris@16: #include <boost/iterator_adaptors.hpp>
Chris@16: 
Chris@16: #include <boost/wave/wave_config.hpp>
Chris@16: #include <boost/wave/token_ids.hpp>     // token_id 
Chris@16: 
Chris@16: // this must occur after all of the includes and before any code appears
Chris@16: #ifdef BOOST_HAS_ABI_HEADERS
Chris@16: #include BOOST_ABI_PREFIX
Chris@16: #endif
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace boost {
Chris@16: namespace wave {
Chris@16: namespace util {
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //
Chris@16: //  unput_queue_iterator
Chris@16: //
Chris@16: //      The unput_queue_iterator templates encapsulates an unput_queue together
Chris@16: //      with the direct input to be read after the unput queue is emptied
Chris@16: //
Chris@16: //      This version is for the new iterator_adaptors (was released with
Chris@16: //      Boost V1.31.0)
Chris@16: //
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: template <typename IteratorT, typename TokenT, typename ContainerT>
Chris@16: class unput_queue_iterator 
Chris@16: :   public boost::iterator_adaptor<
Chris@16:         unput_queue_iterator<IteratorT, TokenT, ContainerT>, 
Chris@16:             IteratorT, TokenT const, std::forward_iterator_tag>
Chris@16: {
Chris@16:     typedef boost::iterator_adaptor<
Chris@16:                 unput_queue_iterator<IteratorT, TokenT, ContainerT>, 
Chris@16:                 IteratorT, TokenT const, std::forward_iterator_tag>
Chris@16:         base_type;
Chris@16: 
Chris@16: public:
Chris@16:     typedef ContainerT  container_type;
Chris@16:     typedef IteratorT   iterator_type;
Chris@16: 
Chris@16:     unput_queue_iterator(IteratorT const &it, ContainerT &queue)
Chris@16:     :   base_type(it), unput_queue(queue)
Chris@16:     {}
Chris@16:     
Chris@16:     ContainerT &get_unput_queue() 
Chris@16:         { return unput_queue; }
Chris@16:     ContainerT const &get_unput_queue() const 
Chris@16:         { return unput_queue; }
Chris@16:     IteratorT &get_base_iterator() 
Chris@16:         { return base_type::base_reference(); }
Chris@16:     IteratorT const &get_base_iterator() const 
Chris@16:         { return base_type::base_reference(); }
Chris@16:     
Chris@16:     unput_queue_iterator &operator= (unput_queue_iterator const &rhs)
Chris@16:     { 
Chris@16:         if (this != &rhs) {
Chris@16:             unput_queue = rhs.unput_queue; 
Chris@16:             base_type::operator=(rhs);
Chris@16:         }
Chris@16:         return *this; 
Chris@16:     }
Chris@16: 
Chris@16:     typename base_type::reference dereference() const
Chris@16:     {
Chris@16:         if (!unput_queue.empty())
Chris@16:             return unput_queue.front();
Chris@16:         return *base_type::base_reference(); 
Chris@16:     }
Chris@16: 
Chris@16:     void increment()
Chris@16:     { 
Chris@16:         if (!unput_queue.empty()) {
Chris@16:         // there exist pending tokens in the unput queue
Chris@16:             unput_queue.pop_front();
Chris@16:         }
Chris@16:         else {
Chris@16:         // the unput_queue is empty, so advance the base iterator
Chris@16:             ++base_type::base_reference(); 
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     template <
Chris@16:         typename OtherDerivedT, typename OtherIteratorT, 
Chris@16:         typename V, typename C, typename R, typename D
Chris@16:     >   
Chris@16:     bool equal(
Chris@16:         boost::iterator_adaptor<OtherDerivedT, OtherIteratorT, V, C, R, D> 
Chris@16:         const &x) const
Chris@16:     {
Chris@16:     // two iterators are equal, if both begin() iterators of the queue 
Chris@16:     // objects are equal and the base iterators are equal as well
Chris@16:         OtherDerivedT const &rhs = static_cast<OtherDerivedT const &>(x);
Chris@16:         return 
Chris@16:             ((unput_queue.empty() && rhs.unput_queue.empty()) ||
Chris@16:               (&unput_queue == &rhs.unput_queue &&
Chris@16:                unput_queue.begin() == rhs.unput_queue.begin()
Chris@16:               )
Chris@16:             ) &&
Chris@16:             (get_base_iterator() == rhs.get_base_iterator()); 
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     ContainerT &unput_queue;
Chris@16: };
Chris@16: 
Chris@16: namespace impl {
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename IteratorT, typename TokenT, typename ContainerT>
Chris@16:     struct gen_unput_queue_iterator 
Chris@16:     {
Chris@16:         typedef ContainerT  container_type;
Chris@16:         typedef IteratorT iterator_type;
Chris@16:         typedef unput_queue_iterator<IteratorT, TokenT, ContainerT> 
Chris@16:             return_type;
Chris@16: 
Chris@16:         static container_type last;
Chris@16: 
Chris@16:         static return_type
Chris@16:         generate(iterator_type const &it)
Chris@16:         {
Chris@16:             return return_type(it, last);
Chris@16:         }
Chris@16: 
Chris@16:         static return_type
Chris@16:         generate(ContainerT &queue, iterator_type const &it)
Chris@16:         {
Chris@16:             return return_type(it, queue);
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     template <typename IteratorT, typename TokenT, typename ContainerT>
Chris@16:     typename gen_unput_queue_iterator<IteratorT, TokenT, ContainerT>::
Chris@16:           container_type  
Chris@16:         gen_unput_queue_iterator<IteratorT, TokenT, ContainerT>::last = 
Chris@16:             typename gen_unput_queue_iterator<IteratorT, TokenT, ContainerT>::
Chris@16:                   container_type();
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename IteratorT, typename TokenT, typename ContainerT>
Chris@16:     struct gen_unput_queue_iterator<
Chris@16:         unput_queue_iterator<IteratorT, TokenT, ContainerT>, 
Chris@16:             TokenT, ContainerT> 
Chris@16:     {
Chris@16:         typedef ContainerT  container_type;
Chris@16:         typedef unput_queue_iterator<IteratorT, TokenT, ContainerT> 
Chris@16:             iterator_type;
Chris@16:         typedef unput_queue_iterator<IteratorT, TokenT, ContainerT> 
Chris@16:             return_type;
Chris@16: 
Chris@16:         static container_type last;
Chris@16: 
Chris@16:         static return_type 
Chris@16:         generate(iterator_type &it)
Chris@16:         {
Chris@16:             return return_type(it.base(), last);
Chris@16:         }
Chris@16: 
Chris@16:         static return_type 
Chris@16:         generate(ContainerT &queue, iterator_type &it)
Chris@16:         {
Chris@16:             return return_type(it.base(), queue);
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename IteratorT>
Chris@16:     struct assign_iterator 
Chris@16:     {
Chris@16:         static void 
Chris@16:         do_ (IteratorT &dest, IteratorT const &src)
Chris@16:         {
Chris@16:             dest = src;
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //
Chris@16:     // Look for the first non-whitespace token and return this token id.
Chris@16:     // Note though, that the embedded unput_queues are not touched in any way!
Chris@16:     //
Chris@16:     template <typename IteratorT>
Chris@16:     struct next_token 
Chris@16:     {
Chris@16:         static boost::wave::token_id  
Chris@16:         peek(IteratorT it, IteratorT end, bool skip_whitespace = true)
Chris@16:         {
Chris@16:             using namespace boost::wave;
Chris@16:             if (skip_whitespace) {
Chris@16:                 for (++it; it != end; ++it) {
Chris@16:                     if (!IS_CATEGORY(*it, WhiteSpaceTokenType) &&
Chris@16:                         T_NEWLINE != token_id(*it))
Chris@16:                     {
Chris@16:                         break;  // stop at the first non-whitespace token
Chris@16:                     }
Chris@16:                 }
Chris@16:             }
Chris@16:             else {
Chris@16:                 ++it;           // we have at least to look ahead
Chris@16:             }
Chris@16:             if (it != end) 
Chris@16:                 return token_id(*it);
Chris@16:             return T_EOI;
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     template <typename IteratorT, typename TokenT, typename ContainerT>
Chris@16:     struct next_token<
Chris@16:         unput_queue_iterator<IteratorT, TokenT, ContainerT> > {
Chris@16: 
Chris@16:         typedef unput_queue_iterator<IteratorT, TokenT, ContainerT> iterator_type;
Chris@16: 
Chris@16:         static boost::wave::token_id 
Chris@16:         peek(iterator_type it, iterator_type end, bool skip_whitespace = true)
Chris@16:         {
Chris@16:             using namespace boost::wave;
Chris@16: 
Chris@16:         typename iterator_type::container_type &queue = it.get_unput_queue();
Chris@16: 
Chris@16:         // first try to find it in the unput_queue
Chris@16:             if (0 != queue.size()) {
Chris@16:             typename iterator_type::container_type::iterator cit = queue.begin();
Chris@16:             typename iterator_type::container_type::iterator cend = queue.end();
Chris@16: 
Chris@16:                 if (skip_whitespace) {
Chris@16:                     for (++cit; cit != cend; ++cit) {
Chris@16:                         if (!IS_CATEGORY(*cit, WhiteSpaceTokenType) &&
Chris@16:                             T_NEWLINE != token_id(*cit))
Chris@16:                         {
Chris@16:                             break;  // stop at the first non-whitespace token
Chris@16:                         }
Chris@16:                     }
Chris@16:                 }
Chris@16:                 else {
Chris@16:                     ++cit;          // we have at least to look ahead
Chris@16:                 }
Chris@16:                 if (cit != cend) 
Chris@16:                     return token_id(*cit);
Chris@16:             }
Chris@16: 
Chris@16:         // second try to move on into the base iterator stream
Chris@16:         typename iterator_type::iterator_type base_it = it.get_base_iterator();
Chris@16:         typename iterator_type::iterator_type base_end = end.get_base_iterator();
Chris@16: 
Chris@16:             if (0 == queue.size())
Chris@16:                 ++base_it;  // advance, if the unput queue is empty
Chris@16: 
Chris@16:             if (skip_whitespace) {
Chris@16:                 for (/**/; base_it != base_end; ++base_it) {
Chris@16:                     if (!IS_CATEGORY(*base_it, WhiteSpaceTokenType) &&
Chris@16:                         T_NEWLINE != token_id(*base_it))
Chris@16:                     {
Chris@16:                         break;  // stop at the first non-whitespace token
Chris@16:                     }
Chris@16:                 }
Chris@16:             }
Chris@16:             if (base_it == base_end)
Chris@16:                 return T_EOI;
Chris@16: 
Chris@16:             return token_id(*base_it);
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: }   // namespace impl
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: }   // namespace util
Chris@16: }   // namespace wave
Chris@16: }   // namespace boost
Chris@16: 
Chris@16: // the suffix header occurs after all of the code
Chris@16: #ifdef BOOST_HAS_ABI_HEADERS
Chris@16: #include BOOST_ABI_SUFFIX
Chris@16: #endif
Chris@16: 
Chris@16: #endif // !defined(UNPUT_QUEUE_ITERATOR_HPP_76DA23D0_4893_4AD5_ABCC_6CED7CFB89BC_INCLUDED)