luabind/iterator_policy.hpp

   1 // Copyright (c) 2003 Daniel Wallin and Arvid Norberg
   2
   3 // Permission is hereby granted, free of charge, to any person obtaining a
   4 // copy of this software and associated documentation files (the "Software"),
   5 // to deal in the Software without restriction, including without limitation
   6 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
   7 // and/or sell copies of the Software, and to permit persons to whom the
   8 // Software is furnished to do so, subject to the following conditions:
   9
  10 // The above copyright notice and this permission notice shall be included
  11 // in all copies or substantial portions of the Software.
  12
  13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
  14 // ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
  15 // TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
  16 // PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
  17 // SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
  18 // ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  19 // ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
  21 // OR OTHER DEALINGS IN THE SOFTWARE.
  22
  23
  24 #ifndef LUABIND_ITERATOR_POLICY_HPP_INCLUDED
  25 #define LUABIND_ITERATOR_POLICY_HPP_INCLUDED
  26
  27 #include <luabind/config.hpp>
  28 #include <luabind/detail/policy.hpp>
  29 #include <luabind/detail/implicit_cast.hpp>
  30 #include <luabind/detail/convert_to_lua.hpp>
  31 #include <boost/mpl/bool.hpp>
  32
  33 namespace luabind { namespace detail
  34 {
  35         template<class Iter>
  36         struct iterator_state
  37         {
  38                 typedef iterator_state<Iter> self_t;
  39
  40                 static int step(lua_State* L)
  41                 {
  42                         self_t& state = *static_cast<self_t*>(lua_touserdata(L, lua_upvalueindex(1)));
  43
  44                         if (state.start == state.end)
  45                         {
  46                                 lua_pushnil(L);
  47                         }
  48                         else
  49                         {
  50                                 convert_to_lua(L, *state.start);
  51                                 ++state.start;
  52                         }
  53
  54                         return 1;
  55                 }
  56
  57                 iterator_state(const Iter& s, const Iter& e)
  58                         : start(s)
  59                         , end(e)
  60                 {}
  61
  62                 Iter start;
  63                 Iter end;
  64         };
  65
  66         struct iterator_converter
  67         {
  68                 typedef boost::mpl::bool_<false> is_value_converter;
  69                 typedef iterator_converter type;
  70
  71                 template<class T>
  72                 void apply(lua_State* L, const T& c)
  73                 {
  74                         typedef typename T::const_iterator iter_t;
  75                         typedef iterator_state<iter_t> state_t;
  76
  77                         // note that this should be destructed, for now.. just hope that iterator
  78                         // is a pod
  79                         void* iter = lua_newuserdata(L, sizeof(state_t));
  80                         new (iter) state_t(c.begin(), c.end());
  81                         lua_pushcclosure(L, state_t::step, 1);
  82                 }
  83
  84                 template<class T>
  85                 void apply(lua_State* L, T& c)
  86                 {
  87                         typedef typename T::iterator iter_t;
  88                         typedef iterator_state<iter_t> state_t;
  89
  90                         // note that this should be destructed, for now.. just hope that iterator
  91                         // is a pod
  92                         void* iter = lua_newuserdata(L, sizeof(state_t));
  93                         new (iter) state_t(c.begin(), c.end());
  94                         lua_pushcclosure(L, state_t::step, 1);
  95                 }
  96         };
  97
  98         struct iterator_policy : conversion_policy<0>
  99         {
 100                 static void precall(lua_State*, const index_map&) {}
 101                 static void postcall(lua_State*, const index_map&) {}
 102
 103                 template<class T, class Direction>
 104                 struct apply
 105                 {
 106                         typedef iterator_converter type;
 107                 };
 108         };
 109
 110 }}
 111
 112 namespace luabind
 113 {
 114         namespace
 115         {
 116                 LUABIND_ANONYMOUS_FIX detail::policy_cons<detail::iterator_policy, detail::null_type> return_stl_iterator;
 117         }
 118 }
 119
 120 #endif // LUABIND_ITERATOR_POLICY_HPP_INCLUDED
 121