123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200 |
- // 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_17_2008_0103PM)
- #define BOOST_SPIRIT_ITERATOR_SPLIT_FUNCTOR_INPUT_POLICY_JAN_17_2008_0103PM
- #include <boost/spirit/home/support/iterators/multi_pass_fwd.hpp>
- #include <boost/spirit/home/support/iterators/detail/multi_pass.hpp>
- #include <boost/assert.hpp>
- #include <boost/type_traits/is_empty.hpp>
- namespace boost { namespace spirit { namespace iterator_policies
- {
- namespace split_functor_input_is_valid_test_
- {
- template <typename Token>
- inline bool token_is_valid(Token const&)
- {
- return true;
- }
- }
- ///////////////////////////////////////////////////////////////////////////
- // class split_functor_input
- // Implementation of the InputPolicy used by multi_pass
- // split_functor_input gets tokens from a functor
- //
- // This policy should be used when the functor holds two parts of data: a
- // unique part (unique for each instance of the iterator) and a shared
- // part (to be shared between the different copies of the same iterator).
- // Using this policy allows to merge the shared part of the functor with
- // the shared part of the iterator data, saving one pointer and one
- // allocation per iterator instance.
- //
- // The Functor template parameter of this policy is expected to be a
- // std::pair<unique, shared>, where 'unique' and 'shared' represent the
- // respective parts of the functor itself.
- //
- // Note: the unique part of 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 split_functor_input
- {
- ///////////////////////////////////////////////////////////////////////
- template <typename Functor
- , bool FunctorIsEmpty = is_empty<typename Functor::first_type>::value>
- class unique;
- // the unique part of the functor is empty, do not include the functor
- // as a member at all to avoid unnecessary padding bytes to be included
- // into the generated structure
- template <typename Functor>
- class unique<Functor, true> // : public detail::default_input_policy
- {
- protected:
- typedef typename Functor::first_type functor_type;
- typedef typename functor_type::result_type result_type;
- public:
- typedef result_type value_type;
- typedef std::ptrdiff_t difference_type;
- typedef std::ptrdiff_t distance_type;
- typedef result_type const* pointer;
- typedef result_type const& reference;
- protected:
- unique() {}
- explicit unique(Functor const&) {}
- public:
- void swap(unique&) {}
- // get the next token
- template <typename MultiPass>
- static typename MultiPass::reference get_input(MultiPass& mp)
- {
- value_type& curtok = mp.shared()->curtok;
- using namespace split_functor_input_is_valid_test_;
- if (!token_is_valid(curtok))
- functor_type::get_next(mp, curtok);
- return curtok;
- }
- template <typename MultiPass>
- static void advance_input(MultiPass& mp)
- {
- functor_type::get_next(mp, mp.shared()->curtok);
- }
- // 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 == functor_type::eof;
- }
- template <typename MultiPass>
- static bool input_is_valid(MultiPass const&, value_type const& t)
- {
- using namespace split_functor_input_is_valid_test_;
- return token_is_valid(t);
- }
- template <typename MultiPass>
- static void destroy(MultiPass& mp)
- {
- functor_type::destroy(mp);
- }
- };
- // the unique part of the functor is non-empty
- template <typename Functor>
- class unique<Functor, false> : public unique<Functor, true>
- {
- protected:
- typedef typename Functor::first_type functor_type;
- typedef typename functor_type::result_type result_type;
- protected:
- unique() {}
- explicit unique(Functor const& x) : ftor(x.first) {}
- 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 const* pointer;
- typedef result_type const& reference;
- public:
- // get the next token
- template <typename MultiPass>
- static typename MultiPass::reference get_input(MultiPass& mp)
- {
- value_type& curtok = mp.shared()->curtok;
- using namespace split_functor_input_is_valid_test_;
- if (!token_is_valid(curtok))
- functor_type::get_next(mp, curtok);
- return curtok;
- }
- template <typename MultiPass>
- static void advance_input(MultiPass& mp)
- {
- mp.ftor.get_next(mp, mp.shared()->curtok);
- }
- template <typename MultiPass>
- static bool input_is_valid(MultiPass const&, value_type const& t)
- {
- using namespace split_functor_input_is_valid_test_;
- return token_is_valid(t);
- }
- // 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;
- }
- typename Functor::first_type& get_functor() const
- {
- return ftor;
- }
- mutable functor_type ftor;
- };
- ///////////////////////////////////////////////////////////////////////
- template <typename Functor>
- struct shared
- {
- protected:
- typedef typename Functor::first_type functor_type;
- typedef typename functor_type::result_type result_type;
- public:
- explicit shared(Functor const& x) : ftor(x.second), curtok(0) {}
- mutable typename Functor::second_type ftor;
- result_type curtok;
- // silence MSVC warning C4512: assignment operator could not be generated
- BOOST_DELETED_FUNCTION(shared& operator= (shared const&))
- };
- };
- }}}
- #endif
|