| // Copyright (c) 2001-2010 Hartmut Kaiser |
| // |
| // 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_ITERATOR_SPLIT_FUNCTOR_INPUT_POLICY_JAN_16_2008_0448M) |
| #define BOOST_SPIRIT_ITERATOR_SPLIT_FUNCTOR_INPUT_POLICY_JAN_16_2008_0448M |
| |
| #include <boost/spirit/home/support/iterators/multi_pass_fwd.hpp> |
| #include <boost/spirit/home/support/iterators/detail/multi_pass.hpp> |
| #include <boost/assert.hpp> |
| |
| namespace boost { namespace spirit { namespace iterator_policies |
| { |
| namespace is_valid_test_ |
| { |
| template <typename Token> |
| inline bool token_is_valid(Token const&) |
| { |
| return true; |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // class functor_input |
| // Implementation of the InputPolicy used by multi_pass |
| // functor_input gets tokens from a functor |
| // |
| // Note: the functor must have a typedef for result_type |
| // It also must have a static variable of type result_type defined |
| // to represent EOF that is called eof. |
| // |
| /////////////////////////////////////////////////////////////////////////// |
| struct functor_input |
| { |
| /////////////////////////////////////////////////////////////////////// |
| template <typename Functor> |
| class unique : public detail::default_input_policy |
| { |
| private: |
| typedef typename Functor::result_type result_type; |
| |
| protected: |
| unique() {} |
| explicit unique(Functor const& x) : ftor(x) {} |
| |
| void swap(unique& x) |
| { |
| boost::swap(ftor, x.ftor); |
| } |
| |
| public: |
| typedef result_type value_type; |
| typedef std::ptrdiff_t difference_type; |
| typedef std::ptrdiff_t distance_type; |
| typedef result_type* pointer; |
| typedef result_type& reference; |
| |
| public: |
| // get the next token |
| template <typename MultiPass> |
| static typename MultiPass::reference get_input(MultiPass& mp) |
| { |
| value_type& curtok = mp.shared()->curtok; |
| if (!input_is_valid(mp, curtok)) |
| curtok = mp.ftor(); |
| return curtok; |
| } |
| |
| template <typename MultiPass> |
| static void advance_input(MultiPass& mp) |
| { |
| // if mp.shared is NULL then this instance of the multi_pass |
| // represents a end iterator |
| BOOST_ASSERT(0 != mp.shared()); |
| mp.shared()->curtok = mp.ftor(); |
| } |
| |
| // test, whether we reached the end of the underlying stream |
| template <typename MultiPass> |
| static bool input_at_eof(MultiPass const& mp) |
| { |
| return mp.shared()->curtok == mp.ftor.eof; |
| } |
| |
| template <typename MultiPass> |
| static bool input_is_valid(MultiPass const& mp, value_type const& t) |
| { |
| using namespace is_valid_test_; |
| return token_is_valid(t); |
| } |
| |
| Functor& get_functor() const |
| { |
| return ftor; |
| } |
| |
| protected: |
| mutable Functor ftor; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////// |
| template <typename Functor> |
| struct shared |
| { |
| explicit shared(Functor const& x) : curtok(0) {} |
| |
| typename Functor::result_type curtok; |
| }; |
| }; |
| |
| }}} |
| |
| #endif |