luabind/functor.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 #if !BOOST_PP_IS_ITERATING
  24
  25 #ifndef LUABIND_FUNCTOR_HPP_INCLUDED
  26 #define LUABIND_FUNCTOR_HPP_INCLUDED
  27
  28 #include <boost/preprocessor/repeat.hpp>
  29 #include <boost/preprocessor/repetition/enum_params.hpp>
  30 #include <boost/preprocessor/repetition/enum_params.hpp>
  31 #include <boost/preprocessor/iteration/iterate.hpp>
  32 #include <boost/type_traits/is_void.hpp>
  33 #include <boost/mpl/if.hpp>
  34
  35 #include <luabind/config.hpp>
  36 #include <luabind/detail/policy.hpp>
  37 #include <luabind/detail/convert_to_lua.hpp>
  38 #include <luabind/detail/error.hpp>
  39
  40 namespace luabind
  41 {
  42 //template<class Ret>
  43 //class functor;
  44
  45         namespace detail
  46         {
  47
  48                 struct functor_from;
  49
  50
  51                 // if the proxy_functor_caller returns non-void
  52                         template<class Ret, class Tuple>
  53                         class proxy_functor_caller
  54                         {
  55 //                      template<class T> friend class luabind::functor;
  56                         public:
  57
  58                                 proxy_functor_caller(luabind::functor<Ret>* o, const Tuple args)
  59                                         : m_func(o)
  60                                         , m_args(args)
  61                                         , m_called(false)
  62                                 {
  63                                 }
  64
  65                                 proxy_functor_caller(const proxy_functor_caller& rhs)
  66                                         : m_func(rhs.m_func)
  67                                         , m_args(rhs.m_args)
  68                                         , m_called(rhs.m_called)
  69                                 {
  70                                         rhs.m_called = true;
  71                                 }
  72
  73                                 ~proxy_functor_caller()
  74                                 {
  75                                         if (m_called) return;
  76
  77                                         m_called = true;
  78                                         lua_State* L = m_func->lua_state();
  79
  80                                         // get the function
  81                                         m_func->pushvalue();
  82
  83                                         push_args_from_tuple<1>::apply(L, m_args);
  84                                         if (lua_pcall(L, boost::tuples::length<Tuple>::value, 0, 0))
  85                                         {
  86 #ifndef LUABIND_NO_EXCEPTIONS
  87                                                 throw luabind::error();
  88 #else
  89                                                 assert(0);
  90 #endif
  91                                         }
  92                                 }
  93
  94                                 operator Ret()
  95                                 {
  96                                         typename default_policy::template generate_converter<Ret, lua_to_cpp>::type converter;
  97
  98                                         m_called = true;
  99                                         lua_State* L = m_func->lua_state();
 100                                         detail::stack_pop p(L, 1); // pop the return value
 101
 102                                         // get the function
 103                                         m_func->pushvalue();
 104
 105                                         push_args_from_tuple<1>::apply(L, m_args);
 106                                         if (lua_pcall(L, boost::tuples::length<Tuple>::value, 1, 0))
 107                                         {
 108 #ifndef LUABIND_NO_EXCEPTIONS
 109                                                 throw luabind::error();
 110 #else
 111                                                 assert(0);
 112 #endif
 113                                         }
 114
 115 #ifndef LUABIND_NO_ERROR_CHECKING
 116 #ifndef LUABIND_NO_EXCEPTIONS
 117
 118                                         if (converter.match(L, LUABIND_DECORATE_TYPE(Ret), -1) < 0)
 119                                         {
 120                                                 throw cant_convert_return_value();
 121                                         }
 122 #else
 123                                         assert(converter.match(L, LUABIND_DECORATE_TYPE(Ret), -1) >= 0);
 124 #endif
 125 #endif
 126                                         return converter.apply(L, LUABIND_DECORATE_TYPE(Ret), -1);
 127                                 }
 128
 129                                 template<class Policies>
 130                                 Ret operator[](const Policies& p)
 131                                 {
 132                                         typedef typename detail::find_conversion_policy<0, Policies>::type converter_policy;
 133                                         typename converter_policy::template generate_converter<Ret, lua_to_cpp>::type converter;
 134
 135                                         m_called = true;
 136                                         lua_State* L = m_func->lua_state();
 137                                         detail::stack_pop popper(L, 1); // pop the return value
 138
 139                                         // get the function
 140                                         m_func->pushvalue();
 141
 142                                         detail::push_args_from_tuple<1>::apply(L, m_args, p);
 143                                         if (lua_pcall(L, boost::tuples::length<Tuple>::value, 1, 0))
 144                                         {
 145 #ifndef LUABIND_NO_EXCEPTIONS
 146                                                 throw error();
 147 #else
 148                                                 assert(0);
 149 #endif
 150                                         }
 151
 152 #ifndef LUABIND_NO_ERROR_CHECKING
 153 #ifndef LUABIND_NO_EXCEPTIONS
 154
 155                                         if (converter.match(L, LUABIND_DECORATE_TYPE(Ret), -1) < 0)
 156                                         {
 157                                                 throw cant_convert_return_value();
 158                                         }
 159 #else
 160                                         assert(converter.match(L, LUABIND_DECORATE_TYPE(Ret), -1) >= 0);
 161 #endif
 162 #endif
 163                                         return converter.apply(L, LUABIND_DECORATE_TYPE(Ret), -1);
 164                                 }
 165
 166                         private:
 167
 168                                 luabind::functor<Ret>* m_func;
 169                                 Tuple m_args;
 170                                 mutable bool m_called;
 171
 172                         };
 173
 174                 // if the proxy_member_caller returns void
 175                         template<class Tuple>
 176                         class proxy_functor_void_caller
 177                         {
 178 //                      template<class T> friend class luabind::functor;
 179                         public:
 180
 181                                 proxy_functor_void_caller(luabind::functor<void>* o, const Tuple args)
 182                                         : m_func(o)
 183                                         , m_args(args)
 184                                         , m_called(false)
 185                                 {
 186                                 }
 187
 188                                 proxy_functor_void_caller(const proxy_functor_void_caller& rhs)
 189                                         : m_func(rhs.m_func)
 190                                         , m_args(rhs.m_args)
 191                                         , m_called(rhs.m_called)
 192                                 {
 193                                         rhs.m_called = true;
 194                                 }
 195
 196                                 ~proxy_functor_void_caller()
 197                                 {
 198                                         if (m_called) return;
 199
 200                                         m_called = true;
 201                                         lua_State* L = m_func->lua_state();
 202
 203                                         // get the function
 204                                         m_func->pushvalue();
 205
 206                                         push_args_from_tuple<1>::apply(L, m_args);
 207                                         if (lua_pcall(L, boost::tuples::length<Tuple>::value, 0, 0))
 208                                         {
 209 #ifndef LUABIND_NO_EXCEPTIONS
 210                                                 throw luabind::error();
 211 #else
 212                                                 assert(0);
 213 #endif
 214                                         }
 215                                 }
 216
 217                                 template<class Policies>
 218                                 void operator[](const Policies& p)
 219                                 {
 220                                         m_called = true;
 221                                         lua_State* L = m_func->lua_state();
 222
 223                                         // get the function
 224                                         m_func->pushvalue();
 225
 226                                         detail::push_args_from_tuple<1>::apply(L, m_args, p);
 227                                         if (lua_pcall(L, boost::tuples::length<Tuple>::value, 0, 0))
 228                                         {
 229 #ifndef LUABIND_NO_EXCEPTIONS
 230                                                 throw error();
 231 #else
 232                                                 assert(0);
 233 #endif
 234                                         }
 235                                 }
 236
 237                         private:
 238
 239                                 luabind::functor<void>* m_func;
 240                                 Tuple m_args;
 241                                 mutable bool m_called;
 242
 243                         };
 244
 245         } // detail
 246
 247         template<class Ret>
 248         class functor
 249         {
 250         public:
 251
 252                 functor(lua_State* L, const char* name) : L_(L)
 253                 {
 254                         lua_pushstring(L, name);
 255                         lua_gettable(L, LUA_GLOBALSINDEX);
 256                         ref_ = detail::ref(L);
 257                 }
 258
 259                 functor()
 260                         : L_(0)
 261                         , ref_(LUA_NOREF)
 262                 {
 263                 }
 264
 265                 functor(const functor<Ret>& obj): L_(obj.L_)
 266                 {
 267                         lua_getref(L_, obj.ref_);
 268                         ref_ = detail::ref(L_);
 269                 }
 270
 271                 ~functor()
 272                 {
 273                         if (ref_ != LUA_NOREF) detail::unref(L_, ref_);
 274                 }
 275
 276                 // this is a safe substitute for an implicit converter to bool
 277                 typedef void (functor::*member_ptr)() const;
 278                 operator member_ptr() const
 279                 {
 280                         if (is_valid()) return &functor::dummy;
 281                         return 0;
 282                 }
 283
 284                 const functor<Ret>& operator=(const functor<Ret>& rhs)
 285                 {
 286                         L_ = rhs.L_;
 287                         lua_getref(L_, rhs.ref_);
 288                         ref_ = detail::ref(L_);
 289                         return *this;
 290                 }
 291
 292                 bool operator==(const functor<Ret>& rhs) const
 293                 {
 294                         if (ref_ == LUA_NOREF || rhs.ref_ == LUA_NOREF) return false;
 295                         pushvalue();
 296                         rhs.pushvalue();
 297                         bool result = lua_equal(L_, -1, -2) != 0;
 298                         lua_pop(L_, 2);
 299                         return result;
 300                 }
 301
 302                 bool operator!=(const functor<Ret>& rhs) const
 303                 {
 304                         if (ref_ == LUA_NOREF || rhs.ref_ == LUA_NOREF) return true;
 305                         pushvalue();
 306                         rhs.pushvalue();
 307                         bool result = lua_equal(L_, -1, -2) == 0;
 308                         lua_pop(L_, 2);
 309                         return result;
 310                 }
 311
 312                 inline bool is_valid() const { return ref_ != LUA_NOREF; }
 313
 314                 lua_State* lua_state() const { return L_; }
 315                 void pushvalue() const { lua_getref(L_, ref_); }
 316
 317                 #define BOOST_PP_ITERATION_PARAMS_1 (4, (0, LUABIND_MAX_ARITY, <luabind/functor.hpp>, 1))
 318                 #include BOOST_PP_ITERATE()
 319
 320 // TODO: should be private
 321
 322                 functor(lua_State* L, int ref)
 323                         : L_(L)
 324                         , ref_(ref)
 325                 {
 326                 }
 327
 328         private:
 329
 330                 void dummy() const {}
 331
 332                 lua_State* L_;
 333                 int ref_;
 334         };
 335 }
 336
 337 #endif // LUABIND_FUNCTOR_HPP_INCLUDED
 338
 339 #else
 340
 341 #define LUABIND_TUPLE_PARAMS(z, n, data) const A##n *
 342 #define LUABIND_OPERATOR_PARAMS(z, n, data) const A##n & a##n
 343
 344 #if BOOST_PP_ITERATION() > 0
 345         template<BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(), class A)>
 346 #endif
 347         typename boost::mpl::if_<boost::is_void<Ret>
 348                 , luabind::detail::proxy_functor_void_caller<boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> >
 349                 , luabind::detail::proxy_functor_caller<Ret, boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> > >::type
 350         operator()(BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_OPERATOR_PARAMS, _)) const
 351         {
 352                 typedef boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> tuple_t;
 353 #if BOOST_PP_ITERATION() == 0
 354                 tuple_t args;
 355 #else
 356                 tuple_t args(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(), &a));
 357 #endif
 358
 359                 typedef typename boost::mpl::if_<boost::is_void<Ret>
 360                         , luabind::detail::proxy_functor_void_caller<boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> >
 361                         , luabind::detail::proxy_functor_caller<Ret, boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> > >::type proxy_type;
 362
 363                 return proxy_type(const_cast<luabind::functor<Ret>*>(this), args);
 364         }
 365
 366         #define LUABIND_TUPLE_PARAMS(z, n, data) const A##n *
 367         #define LUABIND_OPERATOR_PARAMS(z, n, data) const A##n & a##n
 368
 369 #endif
 370