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