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