123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114 |
- // Copyright (c) 2001-2011 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&, 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&) : curtok(0) {}
- typename Functor::result_type curtok;
- };
- };
- }}}
- #endif
|