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/detail/pcall.hpp>
  40 #include <luabind/error.hpp>
  41 #include <luabind/detail/stack_utils.hpp>
  42
  43 namespace luabind
  44 {
  45 //template<class Ret>
  46 //class functor;
  47
  48         namespace detail
  49         {
  50
  51                 struct functor_from;
  52
  53
  54                 // if the proxy_functor_caller returns non-void
  55                         template<class Ret, class Tuple>
  56                         class proxy_functor_caller
  57                         {
  58 //                      template<class T> friend class luabind::functor;
  59                         public:
  60
  61                                 proxy_functor_caller(luabind::functor<Ret>* o, const Tuple args)
  62                                         : m_func(o)
  63                                         , m_args(args)
  64                                         , m_called(false)
  65                                 {
  66                                 }
  67
  68                                 proxy_functor_caller(const proxy_functor_caller& rhs)
  69                                         : m_func(rhs.m_func)
  70                                         , m_args(rhs.m_args)
  71                                         , m_called(rhs.m_called)
  72                                 {
  73                                         rhs.m_called = true;
  74                                 }
  75
  76                                 ~proxy_functor_caller()
  77                                 {
  78                                         if (m_called) return;
  79
  80                                         m_called = true;
  81                                         lua_State* L = m_func->lua_state();
  82
  83                                         // get the function
  84                                         m_func->pushvalue();
  85
  86                                         push_args_from_tuple<1>::apply(L, m_args);
  87                                         if (pcall(L, boost::tuples::length<Tuple>::value, 0))
  88                                         {
  89 #ifndef LUABIND_NO_EXCEPTIONS
  90                                                 throw luabind::error(L);
  91 #else
  92                                                 error_callback_fun e = get_error_callback();
  93                                                 if (e) e(L);
  94
  95                                                 assert(0 && "the lua function threw an error and exceptions are disabled."
  96                                                         "if you want to handle this error use luabind::set_error_callback()");
  97                                                 std::terminate();
  98 #endif
  99                                         }
 100                                 }
 101
 102                                 operator Ret()
 103                                 {
 104                                         typename default_policy::template generate_converter<Ret, lua_to_cpp>::type converter;
 105
 106                                         m_called = true;
 107                                         lua_State* L = m_func->lua_state();
 108 #ifndef LUABIND_NO_ERROR_CHECKING
 109                                         if (L == 0)
 110                                         {
 111         #ifndef LUABIND_NO_EXCEPTIONS
 112                                                 throw error(L);
 113         #else
 114                                                 error_callback_fun e = get_error_callback();
 115                                                 if (e) e(L);
 116
 117                                                 assert(0 && "tried to call uninitialized functor object."
 118                                                         "if you want to handle this error use luabind::set_error_callback()");
 119                                                 std::terminate();
 120         #endif
 121                                         }
 122 #endif
 123
 124
 125                                         detail::stack_pop p(L, 1); // pop the return value
 126
 127                                         // get the function
 128                                         m_func->pushvalue();
 129
 130                                         push_args_from_tuple<1>::apply(L, m_args);
 131                                         if (pcall(L, boost::tuples::length<Tuple>::value, 1))
 132                                         {
 133 #ifndef LUABIND_NO_EXCEPTIONS
 134                                                 throw luabind::error(L);
 135 #else
 136                                                 error_callback_fun e = get_error_callback();
 137                                                 if (e) e(L);
 138
 139                                                 assert(0 && "the lua function threw an error and exceptions are disabled."
 140                                                         "if you want to handle this error use luabind::set_error_callback()");
 141                                                 std::terminate();
 142 #endif
 143                                         }
 144
 145 #ifndef LUABIND_NO_ERROR_CHECKING
 146
 147                                         if (converter.match(L, LUABIND_DECORATE_TYPE(Ret), -1) < 0)
 148                                         {
 149 #ifndef LUABIND_NO_EXCEPTIONS
 150                                                 throw cast_failed(L, LUABIND_TYPEID(Ret));
 151 #else
 152                                                 cast_failed_callback_fun e = get_cast_failed_callback();
 153                                                 if (e) e(L, LUABIND_TYPEID(Ret));
 154
 155                                                 assert(0 && "the lua function's return value could not be converted."
 156                                                                 "if you want to handle this error use luabind::set_error_callback()");
 157                                                 std::terminate();
 158 #endif
 159                                         }
 160 #endif
 161                                         return converter.apply(L, LUABIND_DECORATE_TYPE(Ret), -1);
 162                                 }
 163
 164                                 template<class Policies>
 165                                 Ret operator[](const Policies& p)
 166                                 {
 167                                         typedef typename detail::find_conversion_policy<0, Policies>::type converter_policy;
 168                                         typename converter_policy::template generate_converter<Ret, lua_to_cpp>::type converter;
 169
 170                                         m_called = true;
 171                                         lua_State* L = m_func->lua_state();
 172 #ifndef LUABIND_NO_ERROR_CHECKING
 173                                         if (L == 0)
 174                                         {
 175         #ifndef LUABIND_NO_EXCEPTIONS
 176                                                 throw error(L);
 177         #else
 178                                                 error_callback_fun e = get_error_callback();
 179                                                 if (e) e(L);
 180
 181                                                 assert(0 && "tried to call uninitialized functor object."
 182                                                         "if you want to handle this error use luabind::set_error_callback()");
 183                                                 std::terminate();
 184         #endif
 185                                         }
 186 #endif
 187
 188                                         detail::stack_pop popper(L, 1); // pop the return value
 189
 190                                         // get the function
 191                                         m_func->pushvalue();
 192
 193                                         detail::push_args_from_tuple<1>::apply(L, m_args, p);
 194                                         if (pcall(L, boost::tuples::length<Tuple>::value, 1))
 195                                         {
 196 #ifndef LUABIND_NO_EXCEPTIONS
 197                                                 throw error(L);
 198 #else
 199                                                 error_callback_fun e = get_error_callback();
 200                                                 if (e) e(L);
 201
 202                                                 assert(0 && "the lua function threw an error and exceptions are disabled."
 203                                                         "if you want to handle this error use luabind::set_error_callback()");
 204                                                 std::terminate();
 205 #endif
 206                                         }
 207
 208 #ifndef LUABIND_NO_ERROR_CHECKING
 209
 210                                         if (converter.match(L, LUABIND_DECORATE_TYPE(Ret), -1) < 0)
 211                                         {
 212 #ifndef LUABIND_NO_EXCEPTIONS
 213                                                 throw cast_failed(L, LUABIND_TYPEID(Ret));
 214 #else
 215                                                 cast_failed_callback_fun e = get_cast_failed_callback();
 216                                                 if (e) e(L, LUABIND_TYPEID(Ret));
 217
 218                                                 assert(0 && "the lua function's return value could not be converted."
 219                                                         "if you want to handle this error use luabind::set_error_callback()");
 220                                                 std::terminate();
 221 #endif
 222                                         }
 223 #endif
 224                                         return converter.apply(L, LUABIND_DECORATE_TYPE(Ret), -1);
 225                                 }
 226
 227                         private:
 228
 229                                 luabind::functor<Ret>* m_func;
 230                                 Tuple m_args;
 231                                 mutable bool m_called;
 232
 233                         };
 234
 235                 // if the proxy_member_caller returns void
 236                         template<class Tuple>
 237                         class proxy_functor_void_caller
 238                         {
 239 //                      template<class T> friend class luabind::functor;
 240                         public:
 241
 242                                 proxy_functor_void_caller(luabind::functor<void>* o, const Tuple args)
 243                                         : m_func(o)
 244                                         , m_args(args)
 245                                         , m_called(false)
 246                                 {
 247                                 }
 248
 249                                 proxy_functor_void_caller(const proxy_functor_void_caller& rhs)
 250                                         : m_func(rhs.m_func)
 251                                         , m_args(rhs.m_args)
 252                                         , m_called(rhs.m_called)
 253                                 {
 254                                         rhs.m_called = true;
 255                                 }
 256
 257                                 ~proxy_functor_void_caller()
 258                                 {
 259                                         if (m_called) return;
 260
 261                                         m_called = true;
 262                                         lua_State* L = m_func->lua_state();
 263 #ifndef LUABIND_NO_ERROR_CHECKING
 264                                         if (L == 0)
 265                                         {
 266         #ifndef LUABIND_NO_EXCEPTIONS
 267                                                 throw error(L);
 268         #else
 269                                                 error_callback_fun e = get_error_callback();
 270                                                 if (e) e(L);
 271
 272                                                 assert(0 && "tried to call uninitialized functor object."
 273                                                         "if you want to handle this error use luabind::set_error_callback()");
 274                                                 std::terminate();
 275         #endif
 276                                         }
 277 #endif
 278
 279
 280                                         // get the function
 281                                         m_func->pushvalue();
 282
 283                                         push_args_from_tuple<1>::apply(L, m_args);
 284                                         if (pcall(L, boost::tuples::length<Tuple>::value, 0))
 285                                         {
 286 #ifndef LUABIND_NO_EXCEPTIONS
 287                                                 throw luabind::error(L);
 288 #else
 289                                                 error_callback_fun e = get_error_callback();
 290                                                 if (e) e(L);
 291
 292                                                 assert(0 && "the lua function threw an error and exceptions are disabled."
 293                                                         "if you want to handle this error use luabind::set_error_callback()");
 294                                                 std::terminate();
 295 #endif
 296                                         }
 297                                 }
 298
 299                                 template<class Policies>
 300                                 void operator[](const Policies& p)
 301                                 {
 302                                         m_called = true;
 303                                         lua_State* L = m_func->lua_state();
 304 #ifndef LUABIND_NO_ERROR_CHECKING
 305                                         if (L == 0)
 306                                         {
 307         #ifndef LUABIND_NO_EXCEPTIONS
 308                                                 throw error(L);
 309         #else
 310                                                 error_callback_fun e = get_error_callback();
 311                                                 if (e) e(L);
 312
 313                                                 assert(0 && "tried to call uninitialized functor object."
 314                                                         "if you want to handle this error use luabind::set_error_callback()");
 315                                                 std::terminate();
 316         #endif
 317                                         }
 318 #endif
 319
 320
 321                                         // get the function
 322                                         m_func->pushvalue();
 323
 324                                         detail::push_args_from_tuple<1>::apply(L, m_args, p);
 325                                         if (pcall(L, boost::tuples::length<Tuple>::value, 0))
 326                                         {
 327 #ifndef LUABIND_NO_EXCEPTIONS
 328                                                 throw error(L);
 329 #else
 330                                                 error_callback_fun e = get_error_callback();
 331                                                 if (e) e(L);
 332
 333                                                 assert(0 && "the lua function threw an error and exceptions are disabled."
 334                                                         "if you want to handle this error use luabind::set_error_callback()");
 335                                                 std::terminate();
 336 #endif
 337                                         }
 338                                 }
 339
 340                         private:
 341
 342                                 luabind::functor<void>* m_func;
 343                                 Tuple m_args;
 344                                 mutable bool m_called;
 345
 346                         };
 347
 348         } // detail
 349
 350         template<class Ret>
 351         class functor
 352         {
 353         public:
 354
 355                 functor(lua_State* L, const char* name)
 356                         : L_(L)
 357                 {
 358                         lua_pushstring(L, name);
 359                         lua_gettable(L, LUA_GLOBALSINDEX);
 360                         ref_.set(L_);
 361                 }
 362
 363                 functor()
 364                         : L_(0)
 365                 {
 366                 }
 367
 368                 functor(const functor<Ret>& obj)
 369                         : L_(obj.L_)
 370                         , ref_(obj.ref_)
 371                 {
 372                 }
 373
 374                 // this is a safe substitute for an implicit converter to bool
 375                 typedef void (functor::*member_ptr)() const;
 376                 operator member_ptr() const
 377                 {
 378                         if (is_valid()) return &functor::dummy;
 379                         return 0;
 380                 }
 381
 382                 const functor<Ret>& operator=(const functor<Ret>& rhs)
 383                 {
 384                         L_ = rhs.L_;
 385                         ref_ = rhs.ref_;
 386                         return *this;
 387                 }
 388
 389                 bool operator==(const functor<Ret>& rhs) const
 390                 {
 391                         if (!ref_.is_valid() || !rhs.ref_.is_valid()) return false;
 392                         pushvalue();
 393                         rhs.pushvalue();
 394                         bool result = lua_equal(L_, -1, -2) != 0;
 395                         lua_pop(L_, 2);
 396                         return result;
 397                 }
 398
 399                 bool operator!=(const functor<Ret>& rhs) const
 400                 {
 401                         if (!ref_.is_valid() || !rhs.ref_.is_valid()) return true;
 402                         pushvalue();
 403                         rhs.pushvalue();
 404                         bool result = lua_equal(L_, -1, -2) == 0;
 405                         lua_pop(L_, 2);
 406                         return result;
 407                 }
 408
 409                 inline bool is_valid() const { return ref_.is_valid(); }
 410
 411                 lua_State* lua_state() const { return L_; }
 412                 void pushvalue() const { ref_.get(L_); }
 413
 414                 void reset()
 415                 {
 416                         L_ = 0;
 417                         ref_.reset();
 418                 }
 419
 420                 #define BOOST_PP_ITERATION_PARAMS_1 (4, (0, LUABIND_MAX_ARITY, <luabind/functor.hpp>, 1))
 421                 #include BOOST_PP_ITERATE()
 422
 423 // TODO: should be private
 424
 425                 functor(lua_State* L, detail::lua_reference const& ref)
 426                         : L_(L)
 427                         , ref_(ref)
 428                 {
 429                 }
 430
 431         private:
 432
 433                 void dummy() const {}
 434
 435                 lua_State* L_;
 436                 detail::lua_reference ref_;
 437         };
 438 }
 439
 440 #endif // LUABIND_FUNCTOR_HPP_INCLUDED
 441
 442 #else
 443
 444 #define LUABIND_TUPLE_PARAMS(z, n, data) const A##n *
 445 #define LUABIND_OPERATOR_PARAMS(z, n, data) const A##n & a##n
 446
 447 #if BOOST_PP_ITERATION() > 0
 448         template<BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(), class A)>
 449 #endif
 450         typename boost::mpl::if_<boost::is_void<Ret>
 451                 , luabind::detail::proxy_functor_void_caller<boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> >
 452                 , luabind::detail::proxy_functor_caller<Ret, boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> > >::type
 453         operator()(BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_OPERATOR_PARAMS, _)) const
 454         {
 455                 typedef boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> tuple_t;
 456 #if BOOST_PP_ITERATION() == 0
 457                 tuple_t args;
 458 #else
 459                 tuple_t args(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(), &a));
 460 #endif
 461
 462                 typedef typename boost::mpl::if_<boost::is_void<Ret>
 463                         , luabind::detail::proxy_functor_void_caller<boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> >
 464                         , luabind::detail::proxy_functor_caller<Ret, boost::tuples::tuple<BOOST_PP_ENUM(BOOST_PP_ITERATION(), LUABIND_TUPLE_PARAMS, _)> > >::type proxy_type;
 465
 466                 return proxy_type(const_cast<luabind::functor<Ret>*>(this), args);
 467         }
 468
 469         #define LUABIND_TUPLE_PARAMS(z, n, data) const A##n *
 470         #define LUABIND_OPERATOR_PARAMS(z, n, data) const A##n & a##n
 471
 472 #endif
 473