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/prefix.hpp>
  36 #include <luabind/config.hpp>
  37 #include <luabind/detail/policy.hpp>
  38 #include <luabind/detail/convert_to_lua.hpp>
  39 #include <luabind/error.hpp>
  40
  41 namespace luabind
  42 {
  43 //template<class Ret>
  44 //class functor;
  45
  46         namespace detail
  47         {
  48
  49                 struct functor_from;
  50
  51
  52                 // if the proxy_functor_caller returns non-void
  53                         template<class Ret, class Tuple>
  54                         class proxy_functor_caller
  55                         {
  56 //                      template<class T> friend class luabind::functor;
  57                         public:
  58
  59                                 proxy_functor_caller(luabind::functor<Ret>* o, const Tuple args)
  60                                         : m_func(o)
  61                                         , m_args(args)
  62                                         , m_called(false)
  63                                 {
  64                                 }
  65
  66                                 proxy_functor_caller(const proxy_functor_caller& rhs)
  67                                         : m_func(rhs.m_func)
  68                                         , m_args(rhs.m_args)
  69                                         , m_called(rhs.m_called)
  70                                 {
  71                                         rhs.m_called = true;
  72                                 }
  73
  74                                 ~proxy_functor_caller()
  75                                 {
  76                                         if (m_called) return;
  77
  78                                         m_called = true;
  79                                         lua_State* L = m_func->lua_state();
  80
  81                                         // get the function
  82                                         m_func->pushvalue();
  83
  84                                         push_args_from_tuple<1>::apply(L, m_args);
  85                                         if (lua_pcall(L, boost::tuples::length<Tuple>::value, 0, 0))
  86                                         {
  87 #ifndef LUABIND_NO_EXCEPTIONS
  88                                                 throw luabind::error(L);
  89 #else
  90                                                 error_callback_fun e = detail::error_callback::get().err;
  91                                                 if (e) e(L);
  92
  93                                                 assert(0 && "the lua function threw an error and exceptions are disabled."
  94                                                         "if you want to handle this error use luabind::set_error_callback()");
  95                                                 std::terminate();
  96 #endif
  97                                         }
  98                                 }
  99
 100                                 operator Ret()
 101                                 {
 102                                         typename default_policy::template generate_converter<Ret, lua_to_cpp>::type converter;
 103
 104                                         m_called = true;
 105                                         lua_State* L = m_func->lua_state();
 106 #ifndef LUABIND_NO_ERROR_CHECKING
 107                                         if (L == 0)
 108                                         {
 109         #ifndef LUABIND_NO_EXCEPTIONS
 110                                                 throw error(L);
 111         #else
 112                                                 error_callback_fun e = detail::error_callback::get().err;
 113                                                 if (e) e(L);
 114
 115                                                 assert(0 && "tried to call uninitialized functor object."
 116                                                         "if you want to handle this error use luabind::set_error_callback()");
 117                                                 std::terminate();
 118         #endif
 119                                         }
 120 #endif
 121
 122
 123                                         detail::stack_pop p(L, 1); // pop the return value
 124
 125                                         // get the function
 126                                         m_func->pushvalue();
 127
 128                                         push_args_from_tuple<1>::apply(L, m_args);
 129                                         if (lua_pcall(L, boost::tuples::length<Tuple>::value, 1, 0))
 130                                         {
 131 #ifndef LUABIND_NO_EXCEPTIONS
 132                                                 throw luabind::error(L);
 133 #else
 134                                                 error_callback_fun e = detail::error_callback::get().err;
 135                                                 if (e) e(L);
 136
 137                                                 assert(0 && "the lua function threw an error and exceptions are disabled."
 138                                                         "if you want to handle this error use luabind::set_error_callback()");
 139                                                 std::terminate();
 140 #endif
 141                                         }
 142
 143 #ifndef LUABIND_NO_ERROR_CHECKING
 144
 145                                         if (converter.match(L, LUABIND_DECORATE_TYPE(Ret), -1) < 0)
 146                                         {
 147 #ifndef LUABIND_NO_EXCEPTIONS
 148                                                 throw cast_failed(L, LUABIND_TYPEID(Ret));
 149 #else
 150                                                 cast_failed_callback_fun e = detail::error_callback::get().cast;
 151                                                 if (e) e(L, LUABIND_TYPEID(Ret));
 152
 153                                                 assert(0 && "the lua function's return value could not be converted."
 154                                                                 "if you want to handle this error use luabind::set_error_callback()");
 155                                                 std::terminate();
 156 #endif
 157                                         }
 158 #endif
 159                                         return converter.apply(L, LUABIND_DECORATE_TYPE(Ret), -1);
 160                                 }
 161
 162                                 template<class Policies>
 163                                 Ret operator[](const Policies& p)
 164                                 {
 165                                         typedef typename detail::find_conversion_policy<0, Policies>::type converter_policy;
 166                                         typename converter_policy::template generate_converter<Ret, lua_to_cpp>::type converter;
 167
 168                                         m_called = true;
 169                                         lua_State* L = m_func->lua_state();
 170 #ifndef LUABIND_NO_ERROR_CHECKING
 171                                         if (L == 0)
 172                                         {
 173         #ifndef LUABIND_NO_EXCEPTIONS
 174                                                 throw error(L);
 175         #else
 176                                                 error_callback_fun e = detail::error_callback::get().err;
 177                                                 if (e) e(L);
 178
 179                                                 assert(0 && "tried to call uninitialized functor object."
 180                                                         "if you want to handle this error use luabind::set_error_callback()");
 181                                                 std::terminate();
 182         #endif
 183                                         }
 184 #endif
 185
 186                                         detail::stack_pop popper(L, 1); // pop the return value
 187
 188                                         // get the function
 189                                         m_func->pushvalue();
 190
 191                                         detail::push_args_from_tuple<1>::apply(L, m_args, p);
 192                                         if (lua_pcall(L, boost::tuples::length<Tuple>::value, 1, 0))
 193                                         {
 194 #ifndef LUABIND_NO_EXCEPTIONS
 195                                                 throw error(L);
 196 #else
 197                                                 error_callback_fun e = detail::error_callback::get().err;
 198                                                 if (e) e(L);
 199
 200                                                 assert(0 && "the lua function threw an error and exceptions are disabled."
 201                                                         "if you want to handle this error use luabind::set_error_callback()");
 202                                                 std::terminate();
 203 #endif
 204                                         }
 205
 206 #ifndef LUABIND_NO_ERROR_CHECKING
 207
 208                                         if (converter.match(L, LUABIND_DECORATE_TYPE(Ret), -1) < 0)
 209                                         {
 210 #ifndef LUABIND_NO_EXCEPTIONS
 211                                                 throw cast_failed(L, LUABIND_TYPEID(Ret));
 212 #else
 213                                                 cast_failed_callback_fun e = detail::error_callback::get().cast;
 214                                                 if (e) e(L, LUABIND_TYPEID(Ret));
 215
 216                                                 assert(0 && "the lua function's return value could not be converted."
 217                                                         "if you want to handle this error use luabind::set_error_callback()");
 218                                                 std::terminate();
 219 #endif
 220                                         }
 221 #endif
 222                                         return converter.apply(L, LUABIND_DECORATE_TYPE(Ret), -1);
 223                                 }
 224
 225                         private:
 226
 227                                 luabind::functor<Ret>* m_func;
 228                                 Tuple m_args;
 229                                 mutable bool m_called;
 230
 231                         };
 232
 233                 // if the proxy_member_caller returns void
 234                         template<class Tuple>
 235                         class proxy_functor_void_caller
 236                         {
 237 //                      template<class T> friend class luabind::functor;
 238                         public:
 239
 240                                 proxy_functor_void_caller(luabind::functor<void>* o, const Tuple args)
 241                                         : m_func(o)
 242                                         , m_args(args)
 243                                         , m_called(false)
 244                                 {
 245                                 }
 246
 247                                 proxy_functor_void_caller(const proxy_functor_void_caller& rhs)
 248                                         : m_func(rhs.m_func)
 249                                         , m_args(rhs.m_args)
 250                                         , m_called(rhs.m_called)
 251                                 {
 252                                         rhs.m_called = true;
 253                                 }
 254
 255                                 ~proxy_functor_void_caller()
 256                                 {
 257                                         if (m_called) return;
 258
 259                                         m_called = true;
 260                                         lua_State* L = m_func->lua_state();
 261 #ifndef LUABIND_NO_ERROR_CHECKING
 262                                         if (L == 0)
 263                                         {
 264         #ifndef LUABIND_NO_EXCEPTIONS
 265                                                 throw error(L);
 266         #else
 267                                                 error_callback_fun e = detail::error_callback::get().err;
 268                                                 if (e) e(L);
 269
 270                                                 assert(0 && "tried to call uninitialized functor object."
 271                                                         "if you want to handle this error use luabind::set_error_callback()");
 272                                                 std::terminate();
 273         #endif
 274                                         }
 275 #endif
 276
 277
 278                                         // get the function
 279                                         m_func->pushvalue();
 280
 281                                         push_args_from_tuple<1>::apply(L, m_args);
 282                                         if (lua_pcall(L, boost::tuples::length<Tuple>::value, 0, 0))
 283                                         {
 284 #ifndef LUABIND_NO_EXCEPTIONS
 285                                                 throw luabind::error(L);
 286 #else
 287                                                 error_callback_fun e = detail::error_callback::get().err;
 288                                                 if (e) e(L);
 289
 290                                                 assert(0 && "the lua function threw an error and exceptions are disabled."
 291                                                         "if you want to handle this error use luabind::set_error_callback()");
 292                                                 std::terminate();
 293 #endif
 294                                         }
 295                                 }
 296
 297                                 template<class Policies>
 298                                 void operator[](const Policies& p)
 299                                 {
 300                                         m_called = true;
 301                                         lua_State* L = m_func->lua_state();
 302 #ifndef LUABIND_NO_ERROR_CHECKING
 303                                         if (L == 0)
 304                                         {
 305         #ifndef LUABIND_NO_EXCEPTIONS
 306                                                 throw error(L);
 307         #else
 308                                                 error_callback_fun e = detail::error_callback::get().err;
 309                                                 if (e) e(L);
 310
 311                                                 assert(0 && "tried to call uninitialized functor object."
 312                                                         "if you want to handle this error use luabind::set_error_callback()");
 313                                                 std::terminate();
 314         #endif
 315                                         }
 316 #endif
 317
 318
 319                                         // get the function
 320                                         m_func->pushvalue();
 321
 322                                         detail::push_args_from_tuple<1>::apply(L, m_args, p);
 323                                         if (lua_pcall(L, boost::tuples::length<Tuple>::value, 0, 0))
 324                                         {
 325 #ifndef LUABIND_NO_EXCEPTIONS
 326                                                 throw error(L);
 327 #else
 328                                                 error_callback_fun e = detail::error_callback::get().err;
 329                                                 if (e) e(L);
 330
 331                                                 assert(0 && "the lua function threw an error and exceptions are disabled."
 332                                                         "if you want to handle this error use luabind::set_error_callback()");
 333                                                 std::terminate();
 334 #endif
 335                                         }
 336                                 }
 337
 338                         private:
 339
 340                                 luabind::functor<void>* m_func;
 341                                 Tuple m_args;
 342                                 mutable bool m_called;
 343
 344                         };
 345
 346         } // detail
 347
 348         template<class Ret>
 349         class functor
 350         {
 351         public:
 352
 353                 functor(lua_State* L, const char* name)
 354                         : L_(L)
 355                 {
 356                         lua_pushstring(L, name);
 357                         lua_gettable(L, LUA_GLOBALSINDEX);
 358                         ref_.set(L_);
 359                 }
 360
 361                 functor()
 362                         : L_(0)
 363                 {
 364                 }
 365
 366                 functor(const functor<Ret>& obj)
 367                         : L_(obj.L_)
 368                         , ref_(obj.ref_)
 369                 {
 370                 }
 371
 372                 // this is a safe substitute for an implicit converter to bool
 373                 typedef void (functor::*member_ptr)() const;
 374                 operator member_ptr() const
 375                 {
 376                         if (is_valid()) return &functor::dummy;
 377                         return 0;
 378                 }
 379
 380                 const functor<Ret>& operator=(const functor<Ret>& rhs)
 381                 {
 382                         L_ = rhs.L_;
 383                         ref_ = rhs.ref_;
 384                         return *this;
 385                 }
 386
 387                 bool operator==(const functor<Ret>& rhs) const
 388                 {
 389                         if (!ref_.is_valid() || !rhs.ref_.is_valid()) return false;
 390                         pushvalue();
 391                         rhs.pushvalue();
 392                         bool result = lua_equal(L_, -1, -2) != 0;
 393                         lua_pop(L_, 2);
 394                         return result;
 395                 }
 396
 397                 bool operator!=(const functor<Ret>& rhs) const
 398                 {
 399                         if (!ref_.is_valid() || !rhs.ref_.is_valid()) return true;
 400                         pushvalue();
 401                         rhs.pushvalue();
 402                         bool result = lua_equal(L_, -1, -2) == 0;
 403                         lua_pop(L_, 2);
 404                         return result;
 405                 }
 406
 407                 inline bool is_valid() const { return ref_.is_valid(); }
 408
 409                 lua_State* lua_state() const { return L_; }
 410                 void pushvalue() const { ref_.get(L_); }
 411
 412                 #define BOOST_PP_ITERATION_PARAMS_1 (4, (0, LUABIND_MAX_ARITY, <luabind/functor.hpp>, 1))
 413                 #include BOOST_PP_ITERATE()
 414
 415 // TODO: should be private
 416
 417                 functor(lua_State* L, detail::lua_reference const& ref)
 418                         : L_(L)
 419                         , ref_(ref)
 420                 {
 421                 }
 422
 423         private:
 424
 425                 void dummy() const {}
 426
 427                 lua_State* L_;
 428                 detail::lua_reference ref_;
 429         };
 430 }
 431
 432 #endif // LUABIND_FUNCTOR_HPP_INCLUDED
 433
 434 #else
 435
 436 #define LUABIND_TUPLE_PARAMS(z, n, data) const A##n *
 437 #define LUABIND_OPERATOR_PARAMS(z, n, data) const A##n & a##n
 438
 439 #if BOOST_PP_ITERATION() > 0
 440         template<BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(), class A)>
 441 #endif
 442         typename boost::mpl::if_<boost::is_void<Ret>
 443                 , luabind::detail::proxy_functor_void_caller<boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> >
 444                 , luabind::detail::proxy_functor_caller<Ret, boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> > >::type
 445         operator()(BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_OPERATOR_PARAMS, _)) const
 446         {
 447                 typedef boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> tuple_t;
 448 #if BOOST_PP_ITERATION() == 0
 449                 tuple_t args;
 450 #else
 451                 tuple_t args(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(), &a));
 452 #endif
 453
 454                 typedef typename boost::mpl::if_<boost::is_void<Ret>
 455                         , luabind::detail::proxy_functor_void_caller<boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> >
 456                         , luabind::detail::proxy_functor_caller<Ret, boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> > >::type proxy_type;
 457
 458                 return proxy_type(const_cast<luabind::functor<Ret>*>(this), args);
 459         }
 460
 461         #define LUABIND_TUPLE_PARAMS(z, n, data) const A##n *
 462         #define LUABIND_OPERATOR_PARAMS(z, n, data) const A##n & a##n
 463
 464 #endif
 465