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diff --git a/ext/luawrapper/include/LuaContext.hpp b/ext/luawrapper/include/LuaContext.hpp new file mode 100644 index 0000000..e3a87ee --- /dev/null +++ b/ext/luawrapper/include/LuaContext.hpp @@ -0,0 +1,3002 @@ +/* +Copyright (c) 2013, Pierre KRIEGER +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + * Neither the name of the <organization> nor the + names of its contributors may be used to endorse or promote products + derived from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND +ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY +DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES +(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +*/ + +#ifndef INCLUDE_LUACONTEXT_HPP +#define INCLUDE_LUACONTEXT_HPP + +#include <algorithm> +#include <array> +#include <cassert> +#include <cmath> +#include <cstring> +#include <functional> +#include <limits> +#include <list> +#include <map> +#include <memory> +#include <random> +#include <set> +#include <stdexcept> +#include <string> +#include <sstream> +#include <tuple> +#include <type_traits> +#include <unordered_map> +#include <boost/any.hpp> +#include <boost/format.hpp> +#include <boost/mpl/distance.hpp> +#include <boost/mpl/transform.hpp> +#include <boost/optional.hpp> +#include <boost/variant.hpp> +#include <boost/type_traits.hpp> +#include <lua.hpp> + +#if defined(_MSC_VER) && _MSC_VER < 1900 +# include "misc/exception.hpp" +#endif + +#ifdef __GNUC__ +# define ATTR_UNUSED __attribute__((unused)) +#else +# define ATTR_UNUSED +#endif + +#define LUACONTEXT_GLOBAL_EQ "e5ddced079fc405aa4937b386ca387d2" +#define EQ_FUNCTION_NAME "__eq" +#define TOSTRING_FUNCTION_NAME "__tostring" + +/** + * Defines a Lua context + * A Lua context is used to interpret Lua code. Since everything in Lua is a variable (including functions), + * we only provide few functions like readVariable and writeVariable. + * + * You can also write variables with C++ functions so that they are callable by Lua. Note however that you HAVE TO convert + * your function to std::function (not directly std::bind or a lambda function) so the class can detect which argument types + * it wants. These arguments may only be of basic types (int, float, etc.) or std::string. + */ + +#if defined(__GNUC__) && !defined(__clang__) +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wmaybe-uninitialized" +#endif + +class LuaContext { + struct ValueInRegistry; + template<typename TFunctionObject, typename TFirstParamType> struct Binder; + template<typename T> struct IsOptional; + enum Globals_t { Globals }; // tag for "global variables" +public: + /** + * @param openDefaultLibs True if luaL_openlibs should be called + */ + explicit LuaContext(bool openDefaultLibs = true) + { + // luaL_newstate can return null if allocation failed + mState = luaL_newstate(); + if (mState == nullptr) + throw std::bad_alloc(); + + // setting the panic function + lua_atpanic(mState, [](lua_State* state) -> int { + const std::string str = lua_tostring(state, -1); + lua_pop(state, 1); + assert(false && "lua_atpanic triggered"); + exit(0); + }); + + // opening default library if required to do so + if (openDefaultLibs) + luaL_openlibs(mState); + + writeGlobalEq(); + } + + void writeGlobalEq() { + const auto eqFunction = [](lua_State* lua) -> int { + try { + lua_pushstring(lua, "__eq"); + lua_gettable(lua, -2); + /* if not found, return false */ + if (lua_isnil(lua, -1)) { + lua_pop(lua, -2); + lua_pushboolean(lua, false); + return 1; + } + lua_insert(lua, lua_gettop(lua)-2); + return callRaw(lua, PushedObject{lua, 3}, 1).release(); + } catch(...) { + Pusher<std::exception_ptr>::push(lua, std::current_exception()).release(); + luaError(lua); + } + }; + lua_pushcfunction(mState, eqFunction); + lua_setglobal(mState, LUACONTEXT_GLOBAL_EQ); + }; + + /** + * Move constructor + */ + LuaContext(LuaContext&& s) : + mState(s.mState) + { + s.mState = luaL_newstate(); + } + + /** + * Move operator + */ + LuaContext& operator=(LuaContext&& s) noexcept + { + std::swap(mState, s.mState); + return *this; + } + + /** + * Copy is forbidden + */ + LuaContext(const LuaContext&) = delete; + + /** + * Copy is forbidden + */ + LuaContext& operator=(const LuaContext&) = delete; + + /** + * Destructor + */ + ~LuaContext() noexcept + { + assert(mState); + lua_close(mState); + } + + /** + * Thrown when an error happens during execution of lua code (like not enough parameters for a function) + */ + class ExecutionErrorException : public std::runtime_error + { + public: + ExecutionErrorException(const std::string& msg) : + std::runtime_error(msg) + { + } + }; + + /** + * Thrown when a syntax error happens in a lua script + */ + class SyntaxErrorException : public std::runtime_error + { + public: + SyntaxErrorException(const std::string& msg) : + std::runtime_error(msg) + { + } + }; + + /** + * Thrown when trying to cast a Lua variable to an unvalid type, eg. trying to read a number when the variable is a string + */ + class WrongTypeException : public std::runtime_error + { + public: + WrongTypeException(const std::string& luaType_, const std::type_info& destination_) : + std::runtime_error("Trying to cast a lua variable from \"" + luaType_ + "\" to \"" + destination_.name() + "\""), + luaType(luaType_), + destination(destination_) + { + } + + std::string luaType; + const std::type_info& destination; + }; + + /** + * Function object that can call a function stored by Lua + * This type is copiable and movable, but not constructible. It can only be created through readVariable. + * @tparam TFunctionType Function type (eg. "int (int, bool)") + */ + template<typename TFunctionType> + class LuaFunctionCaller; + + /** + * Opaque type that identifies a Lua object + */ + struct LuaObject { + LuaObject() = default; + LuaObject(lua_State* state, int index=-1) { + this->objectInRegistry = std::make_shared<LuaContext::ValueInRegistry>(state, index); + } + std::shared_ptr<LuaContext::ValueInRegistry> objectInRegistry; + }; + + /** + * Opaque type that identifies a Lua thread + */ + struct ThreadID { + ThreadID() = default; + ThreadID(ThreadID&& o) : state(o.state), threadInRegistry(std::move(o.threadInRegistry)) { } + ThreadID& operator=(ThreadID&& o) { std::swap(state, o.state); std::swap(threadInRegistry, o.threadInRegistry); return *this; } + public: + friend LuaContext; + lua_State* state; + std::unique_ptr<ValueInRegistry> threadInRegistry; + }; + + /** + * Type that is considered as an empty array + */ + enum EmptyArray_t { EmptyArray }; + + /** + * Type for a metatable + */ + enum Metatable_t { Metatable }; + + /** + * Executes lua code from the stream + * @param code A stream that Lua will read its code from + */ + void executeCode(std::istream& code) + { + auto toCall = load(mState, code); + call<std::tuple<>>(mState, std::move(toCall)); + } + + /** + * Executes lua code from the stream and returns a value + * @param code A stream that Lua will read its code from + * @tparam TType The type that the executing code should return + */ + template<typename TType> + auto executeCode(std::istream& code) + -> TType + { + auto toCall = load(mState, code); + return call<TType>(mState, std::move(toCall)); + } + + /** + * Executes lua code given as parameter + * @param code A string containing code that will be executed by Lua + */ + void executeCode(const std::string& code) + { + executeCode(code.c_str()); + } + + /* + * Executes Lua code from the stream and returns a value + * @param code A string containing code that will be executed by Lua + * @tparam TType The type that the executing code should return + */ + template<typename TType> + auto executeCode(const std::string& code) + -> TType + { + return executeCode<TType>(code.c_str()); + } + + /** + * Executes Lua code + * @param code A string containing code that will be executed by Lua + */ + void executeCode(const char* code) + { + auto toCall = load(mState, code); + call<std::tuple<>>(mState, std::move(toCall)); + } + + /* + * Executes Lua code from the stream and returns a value + * @param code A string containing code that will be executed by Lua + * @tparam TType The type that the executing code should return + */ + template<typename TType> + auto executeCode(const char* code) + -> TType + { + auto toCall = load(mState, code); + return call<TType>(mState, std::move(toCall)); + } + + /** + * Executes lua code from the stream + * @param code A stream that Lua will read its code from + */ + void executeCode(const ThreadID& thread, std::istream& code) + { + auto toCall = load(thread.state, code); + call<std::tuple<>>(thread.state, std::move(toCall)); + } + + /** + * Executes lua code from the stream and returns a value + * @param code A stream that Lua will read its code from + * @tparam TType The type that the executing code should return + */ + template<typename TType> + auto executeCode(const ThreadID& thread, std::istream& code) + -> TType + { + auto toCall = load(thread.state, code); + return call<TType>(thread.state, std::move(toCall)); + } + + /** + * Executes lua code given as parameter + * @param code A string containing code that will be executed by Lua + */ + void executeCode(const ThreadID& thread, const std::string& code) + { + executeCode(thread, code.c_str()); + } + + /* + * Executes Lua code from the stream and returns a value + * @param code A string containing code that will be executed by Lua + * @tparam TType The type that the executing code should return + */ + template<typename TType> + auto executeCode(const ThreadID& thread, const std::string& code) + -> TType + { + return executeCode<TType>(thread, code.c_str()); + } + + /** + * Executes Lua code + * @param code A string containing code that will be executed by Lua + */ + void executeCode(const ThreadID& thread, const char* code) + { + auto toCall = load(thread.state, code); + call<std::tuple<>>(thread.state, std::move(toCall)); + } + + /* + * Executes Lua code from the stream and returns a value + * @param code A string containing code that will be executed by Lua + * @tparam TType The type that the executing code should return + */ + template<typename TType> + auto executeCode(const ThreadID& thread, const char* code) + -> TType + { + auto toCall = load(thread.state, code); + return call<TType>(thread.state, std::move(toCall)); + } + + /** + * Tells that Lua will be allowed to access an object's function + * This is the version "registerFunction(name, &Foo::function)" + */ + template<typename TPointerToMemberFunction> + auto registerFunction(const std::string& name, TPointerToMemberFunction pointer) + -> typename std::enable_if<std::is_member_function_pointer<TPointerToMemberFunction>::value>::type + { + registerFunctionImpl(name, std::mem_fn(pointer), tag<TPointerToMemberFunction>{}); + } + + /** + * Tells that Lua will be allowed to access an object's function + * This is the version with an explicit template parameter: "registerFunction<void (Foo::*)()>(name, [](Foo&) { })" + * @param fn Function object which takes as first parameter a reference to the object + * @tparam TFunctionType Pointer-to-member function type + */ + template<typename TFunctionType, typename TType> + void registerFunction(const std::string& functionName, TType fn) + { + static_assert(std::is_member_function_pointer<TFunctionType>::value, "registerFunction must take a member function pointer type as template parameter"); + registerFunctionImpl(functionName, std::move(fn), tag<TFunctionType>{}); + } + + /** + * Tells that Lua will be allowed to access an object's function + * This is the alternative version with an explicit template parameter: "registerFunction<Foo, void (*)()>(name, [](Foo&) { })" + * @param fn Function object which takes as first parameter a reference to the object + * @tparam TObject Object to register this function to + * @tparam TFunctionType Function type + */ + template<typename TObject, typename TFunctionType, typename TType> + void registerFunction(const std::string& functionName, TType fn) + { + static_assert(std::is_function<TFunctionType>::value, "registerFunction must take a function type as template parameter"); + registerFunctionImpl(functionName, std::move(fn), tag<TObject>{}, tag<TFunctionType>{}); + } + + /** + * Wrappers for registering "__eq" function in case we want to change this to something else some day + */ + + template<typename TPointerToMemberFunction> + auto registerEqFunction(TPointerToMemberFunction pointer) + -> typename std::enable_if<std::is_member_function_pointer<TPointerToMemberFunction>::value>::type + { + registerFunctionImpl(EQ_FUNCTION_NAME, std::mem_fn(pointer), tag<TPointerToMemberFunction>{}); + } + + template<typename TFunctionType, typename TType> + void registerEqFunction(TType fn) + { + static_assert(std::is_member_function_pointer<TFunctionType>::value, "registerFunction must take a member function pointer type as template parameter"); + registerFunctionImpl(EQ_FUNCTION_NAME, std::move(fn), tag<TFunctionType>{}); + } + + template<typename TObject, typename TFunctionType, typename TType> + void registerEqFunction(TType fn) + { + static_assert(std::is_function<TFunctionType>::value, "registerFunction must take a function type as template parameter"); + registerFunctionImpl(EQ_FUNCTION_NAME, std::move(fn), tag<TObject>{}, tag<TFunctionType>{}); + } + + /** + * Wrappers for registering "__tostring" function in case we want to change this to something else some day + */ + + template<typename TPointerToMemberFunction> + auto registerToStringFunction(TPointerToMemberFunction pointer) + -> typename std::enable_if<std::is_member_function_pointer<TPointerToMemberFunction>::value>::type + { + registerFunctionImpl(TOSTRING_FUNCTION_NAME, std::mem_fn(pointer), tag<TPointerToMemberFunction>{}); + } + + template<typename TFunctionType, typename TType> + void registerToStringFunction(TType fn) + { + static_assert(std::is_member_function_pointer<TFunctionType>::value, "registerFunction must take a member function pointer type as template parameter"); + registerFunctionImpl(TOSTRING_FUNCTION_NAME, std::move(fn), tag<TFunctionType>{}); + } + + template<typename TObject, typename TFunctionType, typename TType> + void registerToStringFunction(TType fn) + { + static_assert(std::is_function<TFunctionType>::value, "registerFunction must take a function type as template parameter"); + registerFunctionImpl(TOSTRING_FUNCTION_NAME, std::move(fn), tag<TObject>{}, tag<TFunctionType>{}); + } + + /** + * Inverse operation of registerFunction + * @tparam TType Type whose function belongs to + */ + template<typename TType> + void unregisterFunction(const std::string& /*functionName*/) + { + lua_pushlightuserdata(mState, const_cast<std::type_info*>(&typeid(TType))); + lua_pushnil(mState); + lua_settable(mState, LUA_REGISTRYINDEX); + checkTypeRegistration(mState, &typeid(TType)); + + lua_pushlightuserdata(mState, const_cast<std::type_info*>(&typeid(TType*))); + lua_pushnil(mState); + lua_settable(mState, LUA_REGISTRYINDEX); + checkTypeRegistration(mState, &typeid(TType*)); + + lua_pushlightuserdata(mState, const_cast<std::type_info*>(&typeid(std::shared_ptr<TType>))); + lua_pushnil(mState); + lua_settable(mState, LUA_REGISTRYINDEX); + checkTypeRegistration(mState, &typeid(std::shared_ptr<TType>)); + } + + /** + * Registers a member variable + * This is the version "registerMember(name, &Foo::member)" + */ + template<typename TObject, typename TVarType> + void registerMember(const std::string& name, TVarType TObject::*member) + { + // implementation simply calls the custom member with getter and setter + const auto getter = [=](const TObject& obj) -> TVarType { return obj.*member; }; + const auto setter = [=](TObject& obj, const TVarType& value) { obj.*member = value; }; + registerMember<TVarType (TObject::*)>(name, getter, setter); + } + + /** + * Registers a member variable + * This is the version "registerMember<Foo, int>(name, getter, setter)" + * @tparam TObject Type to register the member to + * @tparam TVarType Type of the member + * @param name Name of the member to register + * @param readFunction Function of type "TVarType (const TObject&)" + * @param writeFunction_ Function of type "void (TObject&, const TVarType&)" + */ + template<typename TObject, typename TVarType, typename TReadFunction, typename TWriteFunction> + void registerMember(const std::string& name, TReadFunction readFunction, TWriteFunction writeFunction_) + { + registerMemberImpl<TObject,TVarType>(name, std::move(readFunction), std::move(writeFunction_)); + } + + /** + * Registers a member variable + * This is the version "registerMember<int (Foo::*)>(name, getter, setter)" + * @tparam TMemberType Pointer to member object representing the type + * @param name Name of the member to register + * @param readFunction Function of type "TVarType (const TObject&)" + * @param writeFunction_ Function of type "void (TObject&, const TVarType&)" + */ + template<typename TMemberType, typename TReadFunction, typename TWriteFunction> + void registerMember(const std::string& name, TReadFunction readFunction, TWriteFunction writeFunction_) + { + static_assert(std::is_member_object_pointer<TMemberType>::value, "registerMember must take a member object pointer type as template parameter"); + registerMemberImpl(tag<TMemberType>{}, name, std::move(readFunction), std::move(writeFunction_)); + } + + /** + * Registers a non-modifiable member variable + * This is the version "registerMember<Foo, int>(name, getter)" + * @tparam TObject Type to register the member to + * @tparam TVarType Type of the member + * @param name Name of the member to register + * @param readFunction Function of type "TVarType (const TObject&)" + */ + template<typename TObject, typename TVarType, typename TReadFunction> + void registerMember(const std::string& name, TReadFunction readFunction) + { + registerMemberImpl<TObject,TVarType>(name, std::move(readFunction)); + } + + /** + * Registers a non-modifiable member variable + * This is the version "registerMember<int (Foo::*)>(name, getter)" + * @tparam TMemberType Pointer to member object representing the type + * @param name Name of the member to register + * @param readFunction Function of type "TVarType (const TObject&)" + */ + template<typename TMemberType, typename TReadFunction> + void registerMember(const std::string& name, TReadFunction readFunction) + { + static_assert(std::is_member_object_pointer<TMemberType>::value, "registerMember must take a member object pointer type as template parameter"); + registerMemberImpl(tag<TMemberType>{}, name, std::move(readFunction)); + } + + /** + * Registers a dynamic member variable + * This is the version "registerMember<Foo, int>(getter, setter)" + * @tparam TObject Type to register the member to + * @tparam TVarType Type of the member + * @param readFunction Function of type "TVarType (const TObject&, const std::string&)" + * @param writeFunction_ Function of type "void (TObject&, const std::string&, const TVarType&)" + */ + template<typename TObject, typename TVarType, typename TReadFunction, typename TWriteFunction> + void registerMember(TReadFunction readFunction, TWriteFunction writeFunction_) + { + registerMemberImpl<TObject,TVarType>(std::move(readFunction), std::move(writeFunction_)); + } + + /** + * Registers a dynamic member variable + * This is the version "registerMember<int (Foo::*)>(getter, setter)" + * @tparam TMemberType Pointer to member object representing the type + * @param readFunction Function of type "TVarType (const TObject&, const std::string&)" + * @param writeFunction_ Function of type "void (TObject&, const std::string&, const TVarType&)" + */ + template<typename TMemberType, typename TReadFunction, typename TWriteFunction> + void registerMember(TReadFunction readFunction, TWriteFunction writeFunction_) + { + static_assert(std::is_member_object_pointer<TMemberType>::value, "registerMember must take a member object pointer type as template parameter"); + registerMemberImpl(tag<TMemberType>{}, std::move(readFunction), std::move(writeFunction_)); + } + + /** + * Registers a dynamic non-modifiable member variable + * This is the version "registerMember<Foo, int>(getter)" + * @tparam TObject Type to register the member to + * @tparam TVarType Type of the member + * @param readFunction Function of type "TVarType (const TObject&, const std::string&)" + */ + template<typename TObject, typename TVarType, typename TReadFunction> + void registerMember(TReadFunction readFunction) + { + registerMemberImpl<TObject, TVarType>(std::move(readFunction)); + } + + /** + * Registers a dynamic non-modifiable member variable + * This is the version "registerMember<int (Foo::*)>(getter)" + * @tparam TMemberType Pointer to member object representing the type + * @param readFunction Function of type "TVarType (const TObject&, const std::string&)" + */ + template<typename TMemberType, typename TReadFunction> + void registerMember(TReadFunction readFunction) + { + static_assert(std::is_member_object_pointer<TMemberType>::value, "registerMember must take a member object pointer type as template parameter"); + registerMemberImpl(tag<TMemberType>{}, std::move(readFunction)); + } + + /** + * Creates a new thread + * A Lua thread is not really a thread, but rather an "execution stack". + * You can destroy the thread by calling destroyThread + * @sa destroyThread + */ + auto createThread() + -> ThreadID + { + ThreadID result; + + result.state = lua_newthread(mState); + result.threadInRegistry = std::unique_ptr<ValueInRegistry>(new ValueInRegistry(mState)); + lua_pop(mState, 1); + + return result; + } + + /** + * Destroys a thread created with createThread + * @sa createThread + */ + void destroyThread(ThreadID& id) + { + id.threadInRegistry.reset(); + } + + /** + * Reads the content of a Lua variable + * + * @tparam TType Type requested for the read + * @throw WrongTypeException When the variable is not convertible to the requested type + * @sa writeVariable + * + * Readable types are all types accepted by writeVariable except nullptr, std::unique_ptr and function pointers + * Additionally supported: + * - LuaFunctionCaller<FunctionType>, which is an alternative to std::function + * - references to custom objects, in which case it will return the object in-place + * + * After the variable name, you can add other parameters. + * If the variable is an array, it will instead get the element of that array whose offset is the second parameter. + * Same applies for third, fourth, etc. parameters. + */ + template<typename TType, typename... TTypes> + TType readVariable(const std::string& name, TTypes&&... elements) const + { + lua_getglobal(mState, name.c_str()); + lookIntoStackTop(mState, std::forward<TTypes>(elements)...); + return readTopAndPop<TType>(mState, PushedObject{mState, 1}); + } + + /** + * @sa readVariable + */ + template<typename TType, typename... TTypes> + TType readVariable(const char* name, TTypes&&... elements) const + { + lua_getglobal(mState, name); + lookIntoStackTop(mState, std::forward<TTypes>(elements)...); + return readTopAndPop<TType>(mState, PushedObject{mState, 1}); + } + + /** + * @sa readVariable + */ + template<typename TType, typename... TTypes> + TType readVariable(const ThreadID& thread, const std::string& name, TTypes&&... elements) const + { + lua_getglobal(thread.state, name.c_str()); + lookIntoStackTop(thread.state, std::forward<TTypes>(elements)...); + return readTopAndPop<TType>(thread.state, PushedObject{thread.state, 1}); + } + + /** + * @sa readVariable + */ + template<typename TType, typename... TTypes> + TType readVariable(const ThreadID& thread, const char* name, TTypes&&... elements) const + { + lua_getglobal(thread.state, name); + lookIntoStackTop(thread.state, std::forward<TTypes>(elements)...); + return readTopAndPop<TType>(thread.state, PushedObject{thread.state, 1}); + } + + /** + * Changes the content of a Lua variable + * + * Accepted values are: + * - all base types (char, short, int, float, double, bool) + * - std::string + * - enums + * - std::vector<> + * - std::vector<std::pair<>>, std::map<> and std::unordered_map<> (the key and value must also be accepted values) + * - std::function<> (all parameters must be accepted values, and return type must be either an accepted value for readVariable or a tuple) + * - std::shared_ptr<> (std::unique_ptr<> are converted to std::shared_ptr<>) + * - nullptr (writes nil) + * - any object + * + * All objects are passed by copy and destroyed by the garbage collector if necessary. + */ + template<typename... TData> + void writeVariable(TData&&... data) noexcept { + static_assert(sizeof...(TData) >= 2, "You must pass at least a variable name and a value to writeVariable"); + typedef typename std::decay<typename std::tuple_element<sizeof...(TData) - 1,std::tuple<TData...>>::type>::type + RealDataType; + static_assert(!std::is_same<typename Tupleizer<RealDataType>::type,RealDataType>::value, "Error: you can't use LuaContext::writeVariable with a tuple"); + + setTable<RealDataType>(mState, Globals, std::forward<TData>(data)...); + } + + /** + * Equivalent to writeVariable(varName, ..., std::function<TFunctionType>(data)); + * This version is more efficient than writeVariable if you want to write functions + */ + template<typename TFunctionType, typename... TData> + void writeFunction(TData&&... data) noexcept { + static_assert(sizeof...(TData) >= 2, "You must pass at least a variable name and a value to writeFunction"); + + setTable<TFunctionType>(mState, Globals, std::forward<TData>(data)...); + } + + /** + * Same as the other writeFunction, except that the template parameter is automatically detected + * This only works if the data is either a native function pointer, or contains one operator() (this is the case for lambdas) + */ + template<typename... TData> + void writeFunction(TData&&... data) noexcept { + static_assert(sizeof...(TData) >= 2, "You must pass at least a variable name and a value to writeFunction"); + typedef typename std::decay<typename std::tuple_element<sizeof...(TData) - 1,std::tuple<TData...>>::type>::type + RealDataType; + typedef typename FunctionTypeDetector<RealDataType>::type + DetectedFunctionType; + + return writeFunction<DetectedFunctionType>(std::forward<TData>(data)...); + } + + +private: + // the state is the most important variable in the class since it is our interface with Lua + // - registered members and functions are stored in tables at offset &typeid(type) of the registry + // each table has its getter functions at offset 0, getter members at offset 1, default getter at offset 2 + // offset 3 is unused, setter members at offset 4, default setter at offset 5 + lua_State* mState; + + + /**************************************************/ + /* PUSH OBJECT */ + /**************************************************/ + struct PushedObject { + PushedObject(lua_State* state_, int num_ = 1) : state(state_), num(num_) {} + ~PushedObject() { assert(lua_gettop(state) >= num); if (num >= 1) lua_pop(state, num); } + + PushedObject& operator=(const PushedObject&) = delete; + PushedObject(const PushedObject&) = delete; + PushedObject& operator=(PushedObject&& other) { std::swap(state, other.state); std::swap(num, other.num); return *this; } + PushedObject(PushedObject&& other) : state(other.state), num(other.num) { other.num = 0; } + + PushedObject operator+(PushedObject&& other) && { PushedObject obj(state, num + other.num); num = 0; other.num = 0; return obj; } + void operator+=(PushedObject&& other) { assert(state == other.state); num += other.num; other.num = 0; } + + auto getState() const -> lua_State* { return state; } + auto getNum() const -> int { return num; } + + int release() { const auto n = num; num = 0; return n; } + void pop() { if (num >= 1) lua_pop(state, num); num = 0; } + void pop(int n) { assert(num >= n); lua_pop(state, n); num -= n; } + + private: + lua_State* state; + int num = 0; + }; + + + /**************************************************/ + /* MISC */ + /**************************************************/ + // type used as a tag + template<typename T> + struct tag {}; + + // tag for "the registry" + enum RegistryTag { Registry }; + + // this function takes a value representing the offset to look into + // it will look into the top element of the stack and replace the element by its content at the given index + template<typename OffsetType1, typename... OffsetTypeOthers> + static void lookIntoStackTop(lua_State* state, OffsetType1&& offset1, OffsetTypeOthers&&... offsetOthers) { + static_assert(Pusher<typename std::decay<OffsetType1>::type>::minSize == 1 && Pusher<typename std::decay<OffsetType1>::type>::maxSize == 1, "Impossible to have a multiple-values index"); + auto p1 = Pusher<typename std::decay<OffsetType1>::type>::push(state, offset1); + lua_gettable(state, -2); + lua_remove(state, -2); + p1.release(); + + lookIntoStackTop(state, std::forward<OffsetTypeOthers>(offsetOthers)...); + } + + template<typename... OffsetTypeOthers> + static void lookIntoStackTop(lua_State* state, Metatable_t, OffsetTypeOthers&&... offsetOthers) { + lua_getmetatable(state, -1); + lua_remove(state, -2); + + lookIntoStackTop(state, std::forward<OffsetTypeOthers>(offsetOthers)...); + } + + static void lookIntoStackTop(lua_State*) { + } + + // equivalent of lua_settable with t[k]=n, where t is the value at the index in the template parameter, k is the second parameter, n is the last parameter, and n is pushed by the function in the first parameter + // if there are more than 3 parameters, parameters 3 to n-1 are considered as sub-indices into the array + // the dataPusher MUST push only one thing on the stack + // TTableIndex must be either LUA_REGISTRYINDEX, LUA_GLOBALSINDEX, LUA_ENVINDEX, or the position of the element on the stack + template<typename TDataType, typename TIndex, typename TData> + static void setTable(lua_State* state, const PushedObject&, TIndex&& index, TData&& data) noexcept + { + static_assert(Pusher<typename std::decay<TIndex>::type>::minSize == 1 && Pusher<typename std::decay<TIndex>::type>::maxSize == 1, "Impossible to have a multiple-values index"); + static_assert(Pusher<typename std::decay<TDataType>::type>::minSize == 1 && Pusher<typename std::decay<TDataType>::type>::maxSize == 1, "Impossible to have a multiple-values data"); + + auto p1 = Pusher<typename std::decay<TIndex>::type>::push(state, index); + auto p2 = Pusher<typename std::decay<TDataType>::type>::push(state, std::forward<TData>(data)); + + lua_settable(state, -3); + p1.release(); + p2.release(); + } + + template<typename TDataType, typename TData> + static void setTable(lua_State* state, const PushedObject&, const std::string& index, TData&& data) noexcept + { + static_assert(Pusher<typename std::decay<TDataType>::type>::minSize == 1 && Pusher<typename std::decay<TDataType>::type>::maxSize == 1, "Impossible to have a multiple-values data"); + + auto p1 = Pusher<typename std::decay<TDataType>::type>::push(state, std::forward<TData>(data)); + lua_setfield(state, -2, index.c_str()); + p1.release(); + } + + template<typename TDataType, typename TData> + static void setTable(lua_State* state, const PushedObject&, const char* index, TData&& data) noexcept + { + static_assert(Pusher<typename std::decay<TDataType>::type>::minSize == 1 && Pusher<typename std::decay<TDataType>::type>::maxSize == 1, "Impossible to have a multiple-values data"); + + auto p1 = Pusher<typename std::decay<TDataType>::type>::push(state, std::forward<TData>(data)); + lua_setfield(state, -2, index); + p1.release(); + } + + template<typename TDataType, typename TData> + static void setTable(lua_State* state, const PushedObject&, Metatable_t, TData&& data) noexcept + { + static_assert(Pusher<typename std::decay<TDataType>::type>::minSize == 1 && Pusher<typename std::decay<TDataType>::type>::maxSize == 1, "Impossible to have a multiple-values data"); + + auto p1 = Pusher<typename std::decay<TDataType>::type>::push(state, std::forward<TData>(data)); + lua_setmetatable(state, -2); + p1.release(); + } + + template<typename TDataType, typename TIndex1, typename TIndex2, typename TIndex3, typename... TIndices> + static auto setTable(lua_State* state, PushedObject&, TIndex1&& index1, TIndex2&& index2, TIndex3&& index3, TIndices&&... indices) noexcept + -> typename std::enable_if<!std::is_same<typename std::decay<TIndex1>::type, Metatable_t>::value>::type + { + static_assert(Pusher<typename std::decay<TIndex1>::type>::minSize == 1 && Pusher<typename std::decay<TIndex1>::type>::maxSize == 1, "Impossible to have a multiple-values index"); + + auto p1 = Pusher<typename std::decay<TIndex1>::type>::push(state, std::forward<TIndex1>(index1)); + lua_gettable(state, -2); + + setTable<TDataType>(state, std::move(p1), std::forward<TIndex2>(index2), std::forward<TIndex3>(index3), std::forward<TIndices>(indices)...); + } + + template<typename TDataType, typename TIndex1, typename TIndex2, typename TIndex3, typename... TIndices> + static auto setTable(lua_State* state, PushedObject&& pushedTable, TIndex1&& index1, TIndex2&& index2, TIndex3&& index3, TIndices&&... indices) noexcept + -> typename std::enable_if<!std::is_same<typename std::decay<TIndex1>::type, Metatable_t>::value>::type + { + static_assert(Pusher<typename std::decay<TIndex1>::type>::minSize == 1 && Pusher<typename std::decay<TIndex1>::type>::maxSize == 1, "Impossible to have a multiple-values index"); + + auto p1 = Pusher<typename std::decay<TIndex1>::type>::push(state, std::forward<TIndex1>(index1)) + std::move(pushedTable); + lua_gettable(state, -2); + + setTable<TDataType>(state, std::move(p1), std::forward<TIndex2>(index2), std::forward<TIndex3>(index3), std::forward<TIndices>(indices)...); + } + + template<typename TDataType, typename TIndex2, typename TIndex3, typename... TIndices> + static void setTable(lua_State* state, PushedObject& pushedObject, Metatable_t, TIndex2&& index2, TIndex3&& index3, TIndices&&... indices) noexcept + { + if (lua_getmetatable(state, -1) == 0) + { + lua_newtable(state); + PushedObject p1{state, 1}; + + setTable<TDataType>(state, p1, std::forward<TIndex2>(index2), std::forward<TIndex3>(index3), std::forward<TIndices>(indices)...); + + lua_setmetatable(state, -2); + p1.release(); + } + else + { + setTable<TDataType>(state, pushedObject, std::forward<TIndex2>(index2), std::forward<TIndex3>(index3), std::forward<TIndices>(indices)...); + } + } + + template<typename TDataType, typename TIndex2, typename TIndex3, typename... TIndices> + static void setTable(lua_State* state, PushedObject&& pushedObject, Metatable_t, TIndex2&& index2, TIndex3&& index3, TIndices&&... indices) noexcept + { + if (lua_getmetatable(state, -1) == 0) + { + lua_newtable(state); + PushedObject p1{state, 1}; + + setTable<TDataType>(state, p1, std::forward<TIndex2>(index2), std::forward<TIndex3>(index3), std::forward<TIndices>(indices)...); + + lua_setmetatable(state, -2); + p1.release(); + } + else + { + setTable<TDataType>(state, std::move(pushedObject), std::forward<TIndex2>(index2), std::forward<TIndex3>(index3), std::forward<TIndices>(indices)...); + } + } + + template<typename TDataType, typename TIndex, typename TData> + static void setTable(lua_State* state, RegistryTag, TIndex&& index, TData&& data) noexcept + { + static_assert(Pusher<typename std::decay<TIndex>::type>::minSize == 1 && Pusher<typename std::decay<TIndex>::type>::maxSize == 1, "Impossible to have a multiple-values index"); + static_assert(Pusher<typename std::decay<TDataType>::type>::minSize == 1 && Pusher<typename std::decay<TDataType>::type>::maxSize == 1, "Impossible to have a multiple-values data"); + + auto p1 = Pusher<typename std::decay<TIndex>::type>::push(state, index); + auto p2 = Pusher<typename std::decay<TDataType>::type>::push(state, std::forward<TData>(data)); + + lua_settable(state, LUA_REGISTRYINDEX); + p1.release(); + p2.release(); + } + + template<typename TDataType, typename TData> + static void setTable(lua_State* state, RegistryTag, const std::string& index, TData&& data) noexcept + { + static_assert(Pusher<typename std::decay<TDataType>::type>::minSize == 1 && Pusher<typename std::decay<TDataType>::type>::maxSize == 1, "Impossible to have a multiple-values data"); + + auto p1 = Pusher<typename std::decay<TDataType>::type>::push(state, std::forward<TData>(data)); + lua_setfield(state, LUA_REGISTRYINDEX, index.c_str()); + p1.release(); + } + + template<typename TDataType, typename TData> + static void setTable(lua_State* state, RegistryTag, const char* index, TData&& data) noexcept + { + static_assert(Pusher<typename std::decay<TDataType>::type>::minSize == 1 && Pusher<typename std::decay<TDataType>::type>::maxSize == 1, "Impossible to have a multiple-values data"); + + auto p1 = Pusher<typename std::decay<TDataType>::type>::push(state, std::forward<TData>(data)); + lua_setfield(state, LUA_REGISTRYINDEX, index); + p1.release(); + } + + template<typename TDataType, typename TIndex1, typename TIndex2, typename TIndex3, typename... TIndices> + static void setTable(lua_State* state, RegistryTag, TIndex1&& index1, TIndex2&& index2, TIndex3&& index3, TIndices&&... indices) noexcept + { + static_assert(Pusher<typename std::decay<TIndex1>::type>::minSize == 1 && Pusher<typename std::decay<TIndex1>::type>::maxSize == 1, "Impossible to have a multiple-values index"); + + auto p1 = Pusher<typename std::decay<TIndex1>::type>::push(state, std::forward<TIndex1>(index1)); + lua_gettable(state, LUA_REGISTRYINDEX); + + setTable<TDataType>(state, std::move(p1), std::forward<TIndex2>(index2), std::forward<TIndex3>(index3), std::forward<TIndices>(indices)...); + } + + template<typename TDataType, typename TIndex, typename TData> + static void setTable(lua_State* state, Globals_t, TIndex&& index, TData&& data) noexcept + { + static_assert(Pusher<typename std::decay<TIndex>::type>::minSize == 1 && Pusher<typename std::decay<TIndex>::type>::maxSize == 1, "Impossible to have a multiple-values index"); + static_assert(Pusher<typename std::decay<TDataType>::type>::minSize == 1 && Pusher<typename std::decay<TDataType>::type>::maxSize == 1, "Impossible to have a multiple-values data"); + + +# if LUA_VERSION_NUM >= 502 + + lua_pushglobaltable(state); + PushedObject p3{state, 1}; + auto p1 = Pusher<typename std::decay<TIndex>::type>::push(state, index); + auto p2 = Pusher<typename std::decay<TDataType>::type>::push(state, std::forward<TData>(data)); + lua_settable(state, -3); + +# else + + auto p1 = Pusher<typename std::decay<TIndex>::type>::push(state, index); + auto p2 = Pusher<typename std::decay<TDataType>::type>::push(state, std::forward<TData>(data)); + lua_settable(state, LUA_GLOBALSINDEX); + +# endif + + p1.release(); + p2.release(); + } + + template<typename TDataType, typename TData> + static void setTable(lua_State* state, Globals_t, const std::string& index, TData&& data) noexcept + { + static_assert(Pusher<typename std::decay<TDataType>::type>::minSize == 1 && Pusher<typename std::decay<TDataType>::type>::maxSize == 1, "Impossible to have a multiple-values data"); + + auto p1 = Pusher<typename std::decay<TDataType>::type>::push(state, std::forward<TData>(data)); + lua_setglobal(state, index.c_str()); + p1.release(); + } + + template<typename TDataType, typename TData> + static void setTable(lua_State* state, Globals_t, const char* index, TData&& data) noexcept + { + static_assert(Pusher<typename std::decay<TDataType>::type>::minSize == 1 && Pusher<typename std::decay<TDataType>::type>::maxSize == 1, "Impossible to have a multiple-values data"); + + auto p1 = Pusher<typename std::decay<TDataType>::type>::push(state, std::forward<TData>(data)); + lua_setglobal(state, index); + p1.release(); + } + + template<typename TDataType, typename TIndex1, typename TIndex2, typename TIndex3, typename... TIndices> + static void setTable(lua_State* state, Globals_t, TIndex1&& index1, TIndex2&& index2, TIndex3&& index3, TIndices&&... indices) noexcept + { + static_assert(Pusher<typename std::decay<TIndex1>::type>::minSize == 1 && Pusher<typename std::decay<TIndex1>::type>::maxSize == 1, "Impossible to have a multiple-values index"); + +# if LUA_VERSION_NUM >= 502 + + lua_pushglobaltable(state); + auto p1 = Pusher<typename std::decay<TIndex1>::type>::push(state, std::forward<TIndex1>(index1)) + PushedObject{state, 1}; + lua_gettable(state, -2); + +# else + + auto p1 = Pusher<typename std::decay<TIndex1>::type>::push(state, std::forward<TIndex1>(index1)); + lua_gettable(state, LUA_GLOBALSINDEX); + +# endif + + setTable<TDataType>(state, std::move(p1), std::forward<TIndex2>(index2), std::forward<TIndex3>(index3), std::forward<TIndices>(indices)...); + } + + // TODO: g++ reports "ambiguous overload" + /*template<typename TDataType, typename TIndex2, typename TIndex3, typename... TIndices> + static void setTable(lua_State* state, Globals_t, const char* index, TIndex2&& index2, TIndex3&& index3, TIndices&&... indices) noexcept + { + lua_getglobal(state, index); + PushedObject p1{state, 1}; + + setTable<TDataType>(state, std::move(p1), std::forward<TIndex2>(index2), std::forward<TIndex3>(index3), std::forward<TIndices>(indices)...); + } + + template<typename TDataType, typename TIndex2, typename TIndex3, typename... TIndices> + static void setTable(lua_State* state, Globals_t, const std::string& index, TIndex2&& index2, TIndex3&& index3, TIndices&&... indices) noexcept + { + lua_getglobal(state, index.c_str()); + PushedObject p1{state, 1}; + + setTable<TDataType>(state, std::move(p1), std::forward<TIndex2>(index2), std::forward<TIndex3>(index3), std::forward<TIndices>(indices)...); + }*/ + + // simple function that reads the "nb" first top elements of the stack, pops them, and returns the value + // warning: first parameter is the number of parameters, not the parameter index + // if read generates an exception, stack is poped anyway + template<typename TReturnType> + static auto readTopAndPop(lua_State* state, PushedObject object) + -> TReturnType + { + auto val = Reader<typename std::decay<TReturnType>::type>::read(state, -object.getNum()); + if (!val.is_initialized()) + throw WrongTypeException{lua_typename(state, lua_type(state, -object.getNum())), typeid(TReturnType)}; + return val.get(); + } + + // checks that the offsets for a type's registrations are set in the registry + static void checkTypeRegistration(lua_State* state, const std::type_info* type) + { + lua_pushlightuserdata(state, const_cast<std::type_info*>(type)); + lua_gettable(state, LUA_REGISTRYINDEX); + if (!lua_isnil(state, -1)) { + lua_pop(state, 1); + return; + } + lua_pop(state, 1); + + lua_pushlightuserdata(state, const_cast<std::type_info*>(type)); + lua_newtable(state); + + lua_pushinteger(state, 0); + lua_newtable(state); + lua_settable(state, -3); + + lua_pushinteger(state, 1); + lua_newtable(state); + lua_settable(state, -3); + + lua_pushinteger(state, 3); + lua_newtable(state); + lua_settable(state, -3); + + lua_pushinteger(state, 4); + lua_newtable(state); + lua_settable(state, -3); + + lua_settable(state, LUA_REGISTRYINDEX); + } + + // +# ifdef _MSC_VER + __declspec(noreturn) +# else + [[noreturn]] +# endif + static void luaError(lua_State* state) + { + lua_error(state); + assert(false); + std::terminate(); // removes compilation warning + } + + + /**************************************************/ + /* FUNCTIONS REGISTRATION */ + /**************************************************/ + // the "registerFunction" public functions call this one + template<typename TFunctionType, typename TRetValue, typename TObject, typename... TOtherParams> + void registerFunctionImpl(const std::string& functionName, TFunctionType function, tag<TObject>, tag<TRetValue (TOtherParams...)>) + { + static_assert(std::is_class<TObject>::value || std::is_pointer<TObject>::value || std::is_union<TObject>::value , "registerFunction can only be used for a class a union or a pointer"); + + checkTypeRegistration(mState, &typeid(TObject)); + setTable<TRetValue(TObject&, TOtherParams...)>(mState, Registry, &typeid(TObject), 0, functionName, function); + + checkTypeRegistration(mState, &typeid(TObject*)); + setTable<TRetValue(TObject*, TOtherParams...)>(mState, Registry, &typeid(TObject*), 0, functionName, [=](TObject* obj, TOtherParams... rest) { assert(obj); return function(*obj, std::forward<TOtherParams>(rest)...); }); + + checkTypeRegistration(mState, &typeid(std::shared_ptr<TObject>)); + setTable<TRetValue(std::shared_ptr<TObject>, TOtherParams...)>(mState, Registry, &typeid(std::shared_ptr<TObject>), 0, functionName, [=](const std::shared_ptr<TObject>& obj, TOtherParams... rest) { assert(obj); return function(*obj, std::forward<TOtherParams>(rest)...); }); + } + + template<typename TFunctionType, typename TRetValue, typename TObject, typename... TOtherParams> + void registerFunctionImpl(const std::string& functionName, TFunctionType function, tag<const TObject>, tag<TRetValue (TOtherParams...)> fTypeTag) + { + registerFunctionImpl(functionName, function, tag<TObject>{}, fTypeTag); + + checkTypeRegistration(mState, &typeid(TObject const*)); + setTable<TRetValue(TObject const*, TOtherParams...)>(mState, Registry, &typeid(TObject const*), 0, functionName, [=](TObject const* obj, TOtherParams... rest) { assert(obj); return function(*obj, std::forward<TOtherParams>(rest)...); }); + + checkTypeRegistration(mState, &typeid(std::shared_ptr<TObject const>)); + setTable<TRetValue(std::shared_ptr<TObject const>, TOtherParams...)>(mState, Registry, &typeid(std::shared_ptr<TObject const>), 0, functionName, [=](const std::shared_ptr<TObject const>& obj, TOtherParams... rest) { assert(obj); return function(*obj, std::forward<TOtherParams>(rest)...); }); + } + + template<typename TFunctionType, typename TRetValue, typename TObject, typename... TOtherParams> + void registerFunctionImpl(const std::string& functionName, TFunctionType function, tag<TRetValue (TObject::*)(TOtherParams...)>) + { + registerFunctionImpl(functionName, std::move(function), tag<TObject>{}, tag<TRetValue (TOtherParams...)>{}); + } + + template<typename TFunctionType, typename TRetValue, typename TObject, typename... TOtherParams> + void registerFunctionImpl(const std::string& functionName, TFunctionType function, tag<TRetValue (TObject::*)(TOtherParams...) const>) + { + registerFunctionImpl(functionName, std::move(function), tag<const TObject>{}, tag<TRetValue (TOtherParams...)>{}); + } + + template<typename TFunctionType, typename TRetValue, typename TObject, typename... TOtherParams> + void registerFunctionImpl(const std::string& functionName, TFunctionType function, tag<TRetValue (TObject::*)(TOtherParams...) volatile>) + { + registerFunctionImpl(functionName, std::move(function), tag<TObject>{}, tag<TRetValue (TOtherParams...)>{}); + } + + template<typename TFunctionType, typename TRetValue, typename TObject, typename... TOtherParams> + void registerFunctionImpl(const std::string& functionName, TFunctionType function, tag<TRetValue (TObject::*)(TOtherParams...) const volatile>) + { + registerFunctionImpl(functionName, std::move(function), tag<const TObject>{}, tag<TRetValue (TOtherParams...)>{}); + } + + // the "registerMember" public functions call this one + template<typename TObject, typename TVarType, typename TReadFunction> + void registerMemberImpl(const std::string& name, TReadFunction readFunction) + { + static_assert(std::is_class<TObject>::value || std::is_pointer<TObject>::value, "registerMember can only be called on a class or a pointer"); + + checkTypeRegistration(mState, &typeid(TObject)); + setTable<TVarType (TObject&)>(mState, Registry, &typeid(TObject), 1, name, [readFunction](TObject const& object) { + return readFunction(object); + }); + + checkTypeRegistration(mState, &typeid(TObject*)); + setTable<TVarType (TObject*)>(mState, Registry, &typeid(TObject*), 1, name, [readFunction](TObject const* object) { + assert(object); + return readFunction(*object); + }); + + checkTypeRegistration(mState, &typeid(TObject const*)); + setTable<TVarType (TObject const*)>(mState, Registry, &typeid(TObject const*), 1, name, [readFunction](TObject const* object) { + assert(object); + return readFunction(*object); + }); + + checkTypeRegistration(mState, &typeid(std::shared_ptr<TObject>)); + setTable<TVarType (std::shared_ptr<TObject>)>(mState, Registry, &typeid(std::shared_ptr<TObject>), 1, name, [readFunction](const std::shared_ptr<TObject>& object) { + assert(object); + return readFunction(*object); + }); + + checkTypeRegistration(mState, &typeid(std::shared_ptr<TObject const>)); + setTable<TVarType (std::shared_ptr<TObject const>)>(mState, Registry, &typeid(std::shared_ptr<TObject const>), 1, name, [readFunction](const std::shared_ptr<TObject const>& object) { + assert(object); + return readFunction(*object); + }); + } + + template<typename TObject, typename TVarType, typename TReadFunction, typename TWriteFunction> + void registerMemberImpl(const std::string& name, TReadFunction readFunction, TWriteFunction writeFunction_) + { + registerMemberImpl<TObject,TVarType>(name, readFunction); + + setTable<void (TObject&, TVarType)>(mState, Registry, &typeid(TObject), 4, name, [writeFunction_](TObject& object, const TVarType& value) { + writeFunction_(object, value); + }); + + setTable<void (TObject*, TVarType)>(mState, Registry, &typeid(TObject*), 4, name, [writeFunction_](TObject* object, const TVarType& value) { + assert(object); + writeFunction_(*object, value); + }); + + setTable<void (std::shared_ptr<TObject>, TVarType)>(mState, Registry, &typeid(std::shared_ptr<TObject>), 4, name, [writeFunction_](std::shared_ptr<TObject> object, const TVarType& value) { + assert(object); + writeFunction_(*object, value); + }); + } + + template<typename TObject, typename TVarType, typename TReadFunction, typename TWriteFunction> + void registerMemberImpl(tag<TVarType (TObject::*)>, const std::string& name, TReadFunction readFunction, TWriteFunction writeFunction_) + { + registerMemberImpl<TObject,TVarType>(name, std::move(readFunction), std::move(writeFunction_)); + } + + template<typename TObject, typename TVarType, typename TReadFunction> + void registerMemberImpl(tag<TVarType(TObject::*)>, const std::string& name, TReadFunction readFunction) + { + registerMemberImpl<TObject, TVarType>(name, std::move(readFunction)); + } + + // the "registerMember" public functions call this one + template<typename TObject, typename TVarType, typename TReadFunction> + void registerMemberImpl(TReadFunction readFunction) + { + checkTypeRegistration(mState, &typeid(TObject)); + setTable<TVarType (TObject const&, std::string)>(mState, Registry, &typeid(TObject), 2, [readFunction](TObject const& object, const std::string& name) { + return readFunction(object, name); + }); + + checkTypeRegistration(mState, &typeid(TObject*)); + setTable<TVarType (TObject*, std::string)>(mState, Registry, &typeid(TObject*), 2, [readFunction](TObject const* object, const std::string& name) { + assert(object); + return readFunction(*object, name); + }); + + checkTypeRegistration(mState, &typeid(TObject const*)); + setTable<TVarType (TObject const*, std::string)>(mState, Registry, &typeid(TObject const*), 2, [readFunction](TObject const* object, const std::string& name) { + assert(object); + return readFunction(*object, name); + }); + + checkTypeRegistration(mState, &typeid(std::shared_ptr<TObject>)); + setTable<TVarType (std::shared_ptr<TObject>, std::string)>(mState, Registry, &typeid(std::shared_ptr<TObject>), 2, [readFunction](const std::shared_ptr<TObject>& object, const std::string& name) { + assert(object); + return readFunction(*object, name); + }); + + checkTypeRegistration(mState, &typeid(std::shared_ptr<TObject const>)); + setTable<TVarType (std::shared_ptr<TObject const>, std::string)>(mState, Registry, &typeid(std::shared_ptr<TObject const>), 2, [readFunction](const std::shared_ptr<TObject const>& object, const std::string& name) { + assert(object); + return readFunction(*object, name); + }); + } + + template<typename TObject, typename TVarType, typename TReadFunction, typename TWriteFunction> + void registerMemberImpl(TReadFunction readFunction, TWriteFunction writeFunction_) + { + registerMemberImpl<TObject,TVarType>(readFunction); + + setTable<void (TObject&, std::string, TVarType)>(mState, Registry, &typeid(TObject), 5, [writeFunction_](TObject& object, const std::string& name, const TVarType& value) { + writeFunction_(object, name, value); + }); + + setTable<void (TObject*, std::string, TVarType)>(mState, Registry, &typeid(TObject*), 2, [writeFunction_](TObject* object, const std::string& name, const TVarType& value) { + assert(object); + writeFunction_(*object, name, value); + }); + + setTable<void (std::shared_ptr<TObject>, std::string, TVarType)>(mState, Registry, &typeid(std::shared_ptr<TObject>), 2, [writeFunction_](const std::shared_ptr<TObject>& object, const std::string& name, const TVarType& value) { + assert(object); + writeFunction_(*object, name, value); + }); + } + + template<typename TObject, typename TVarType, typename TReadFunction, typename TWriteFunction> + void registerMemberImpl(tag<TVarType (TObject::*)>, TReadFunction readFunction, TWriteFunction writeFunction_) + { + registerMemberImpl<TObject,TVarType>(std::move(readFunction), std::move(writeFunction_)); + } + + template<typename TObject, typename TVarType, typename TReadFunction> + void registerMemberImpl(tag<TVarType(TObject::*)>, TReadFunction readFunction) + { + registerMemberImpl<TObject, TVarType>(std::move(readFunction)); + } + + + /**************************************************/ + /* LOADING AND CALLING */ + /**************************************************/ + // this function loads data from the stream and pushes a function at the top of the stack + // throws in case of syntax error + static PushedObject load(lua_State* state, std::istream& code) { + // since the lua_load function requires a static function, we use this structure + // the Reader structure is at the same time an object storing an istream and a buffer, + // and a static function provider + struct Reader { + Reader(std::istream& str) : stream(str) {} + std::istream& stream; + std::array<char,512> buffer; + + // read function ; "data" must be an instance of Reader + static const char* read(lua_State* /*l*/, void* data, size_t* size) { + assert(size != nullptr); + assert(data != nullptr); + Reader& me = *static_cast<Reader*>(data); + if (me.stream.eof()) { *size = 0; return nullptr; } + + me.stream.read(me.buffer.data(), me.buffer.size()); + *size = static_cast<size_t>(me.stream.gcount()); // gcount could return a value larger than a size_t, but its maximum is me.buffer.size() so there's no problem + return me.buffer.data(); + } + }; + + // we create an instance of Reader, and we call lua_load + Reader reader{code}; + const auto loadReturnValue = lua_load(state, &Reader::read, &reader, "chunk" +# if LUA_VERSION_NUM >= 502 + , nullptr +# endif + ); + + // now we have to check return value + if (loadReturnValue != 0) { + // there was an error during loading, an error message was pushed on the stack + const std::string errorMsg = lua_tostring(state, -1); + lua_pop(state, 1); + if (loadReturnValue == LUA_ERRMEM) + throw std::bad_alloc(); + else if (loadReturnValue == LUA_ERRSYNTAX) + throw SyntaxErrorException{errorMsg}; + throw std::runtime_error("Error while calling lua_load: " + errorMsg); + } + + return PushedObject{state, 1}; + } + + // this function loads data and pushes a function at the top of the stack + // throws in case of syntax error + static PushedObject load(lua_State* state, const char* code) { + auto loadReturnValue = luaL_loadstring(state, code); + + // now we have to check return value + if (loadReturnValue != 0) { + // there was an error during loading, an error message was pushed on the stack + const std::string errorMsg = lua_tostring(state, -1); + lua_pop(state, 1); + if (loadReturnValue == LUA_ERRMEM) + throw std::bad_alloc(); + else if (loadReturnValue == LUA_ERRSYNTAX) + throw SyntaxErrorException{errorMsg}; + throw std::runtime_error("Error while calling lua_load: " + errorMsg); + } + + return PushedObject{state, 1}; + } + + // this function calls what is on the top of the stack and removes it (just like lua_call) + // if an exception is triggered, the top of the stack will be removed anyway + template<typename TReturnType, typename... TParameters> + static auto call(lua_State* state, PushedObject toCall, TParameters&&... input) + -> TReturnType + { + typedef typename Tupleizer<TReturnType>::type + RealReturnType; + + // we push the parameters on the stack + auto inArguments = Pusher<std::tuple<TParameters&&...>>::push(state, std::forward_as_tuple(std::forward<TParameters>(input)...)); + + // + const int outArgumentsCount = std::tuple_size<RealReturnType>::value; + auto outArguments = callRaw(state, std::move(toCall) + std::move(inArguments), outArgumentsCount); + + // pcall succeeded, we pop the returned values and return them + return readTopAndPop<TReturnType>(state, std::move(outArguments)); + } + + static int gettraceback(lua_State* L) { + lua_getglobal(L, "debug"); // stack: error, debug library + lua_getfield(L, -1, "traceback"); // stack: error, debug library, debug.traceback function + lua_remove(L, -2); // stack: error, debug.traceback function + lua_pushstring(L, ""); // stack: error, debug.traceback, "" + lua_pushinteger(L, 2); // stack: error, debug.traceback, "", 2 + lua_call(L, 2, 1); // stack: error, traceback + lua_createtable(L, 2, 0); // stack: error, traceback, {} + lua_insert(L, 1); // stack: {}, error, traceback + lua_rawseti(L, 1, 2); // stack: {[2]=traceback}, error + lua_rawseti(L, 1, 1); // stack: {[1]=error,[2]=traceback} + return 1; // return the table + } + + // this function just calls lua_pcall and checks for errors + static PushedObject callRaw(lua_State* state, PushedObject functionAndArguments, const int outArguments) + { + // provide traceback handler + int tbindex = lua_gettop(state) - (functionAndArguments.getNum() - 1); + lua_pushcfunction(state, gettraceback); + + // move it back up, before our function and arguments + lua_insert(state, tbindex); + + // calling pcall automatically pops the parameters and pushes output + const auto pcallReturnValue = lua_pcall(state, functionAndArguments.getNum() - 1, outArguments, tbindex); + functionAndArguments.release(); + + lua_remove(state, tbindex); // remove traceback function + + + // if pcall failed, analyzing the problem and throwing + if (pcallReturnValue != 0) { + + // stack top: {error, traceback} + lua_rawgeti(state, -1, 1); // stack top: {error, traceback}, error + lua_rawgeti(state, -2, 2); // stack top: {error, traceback}, error, traceback + lua_remove(state, -3); // stack top: error, traceback + + PushedObject traceBackRef{state, 1}; + const auto traceBack = readTopAndPop<std::string>(state, std::move(traceBackRef)); // stack top: error + PushedObject errorCode{state, 1}; + + // an error occurred during execution, either an error message or a std::exception_ptr was pushed on the stack + if (pcallReturnValue == LUA_ERRMEM) { + throw std::bad_alloc{}; + + } else if (pcallReturnValue == LUA_ERRRUN) { + if (lua_isstring(state, 1)) { + // the error is a string + const auto str = readTopAndPop<std::string>(state, std::move(errorCode)); + throw ExecutionErrorException{str+traceBack}; + + } else { + // an exception_ptr was pushed on the stack + // rethrowing it with an additional ExecutionErrorException + try { + if (const auto exp = readTopAndPop<std::exception_ptr>(state, std::move(errorCode))) { + std::rethrow_exception(exp); + } + } catch(const std::exception& e) { + std::throw_with_nested(ExecutionErrorException{std::string{"Exception thrown by a callback function: "} + e.what()}); + } catch(...) { + std::throw_with_nested(ExecutionErrorException{"Exception thrown by a callback function called by Lua. "+traceBack}); + } + throw ExecutionErrorException{"Unknown Lua error"}; + } + } + } + + return PushedObject{state, outArguments}; + } + + + /**************************************************/ + /* PUSH FUNCTIONS */ + /**************************************************/ + template<typename T> + static PushedObject push(lua_State* state, T&& value) + { + return Pusher<typename std::decay<T>::type>::push(state, std::forward<T>(value)); + } + + // the Pusher structures allow you to push a value on the stack + // - static const int minSize : minimum size on the stack that the value can have + // - static const int maxSize : maximum size on the stack that the value can have + // - static int push(const LuaContext&, ValueType) : pushes the value on the stack and returns the size on the stack + + // implementation for custom objects + template<typename TType, typename = void> + struct Pusher { + static const int minSize = 1; + static const int maxSize = 1; + + template<typename TType2> + static PushedObject push(lua_State* state, TType2&& value) noexcept { + // this function is called when lua's garbage collector wants to destroy our object + // we simply call its destructor + const auto garbageCallbackFunction = [](lua_State* lua) -> int { + assert(lua_gettop(lua) == 1); + TType* ptr = static_cast<TType*>(lua_touserdata(lua, 1)); + assert(ptr); + ptr->~TType(); + return 0; + }; + + // this function will be stored in __index in the metatable + const auto indexFunction = [](lua_State* lua) -> int { + try { + assert(lua_gettop(lua) == 2); + assert(lua_isuserdata(lua, 1)); + + // searching for a handler + lua_pushlightuserdata(lua, const_cast<std::type_info*>(&typeid(TType))); + lua_gettable(lua, LUA_REGISTRYINDEX); + assert(!lua_isnil(lua, -1)); + + // looking into getter functions + lua_pushinteger(lua, 0); + lua_gettable(lua, -2); + lua_pushvalue(lua, 2); + lua_gettable(lua, -2); + if (!lua_isnil(lua, -1)) + return 1; + lua_pop(lua, 2); + + // looking into getter members + lua_pushinteger(lua, 1); + lua_gettable(lua, -2); + lua_pushvalue(lua, 2); + lua_gettable(lua, -2); + if (!lua_isnil(lua, -1)) { + lua_pushvalue(lua, 1); + return callRaw(lua, PushedObject{lua, 2}, 1).release(); + } + lua_pop(lua, 2); + + // looking into default getter + lua_pushinteger(lua, 2); + lua_gettable(lua, -2); + if (lua_isnil(lua, -1)) + return 1; + lua_pushvalue(lua, 1); + lua_pushvalue(lua, 2); + return callRaw(lua, PushedObject{lua, 3}, 1).release(); + + } catch (...) { + Pusher<std::exception_ptr>::push(lua, std::current_exception()).release(); + luaError(lua); + } + }; + + // this function will be stored in __newindex in the metatable + const auto newIndexFunction = [](lua_State* lua) -> int { + try { + assert(lua_gettop(lua) == 3); + assert(lua_isuserdata(lua, 1)); + + // searching for a handler + lua_pushlightuserdata(lua, const_cast<std::type_info*>(&typeid(TType))); + lua_rawget(lua, LUA_REGISTRYINDEX); + assert(!lua_isnil(lua, -1)); + + // looking into setter members + lua_pushinteger(lua, 4); + lua_rawget(lua, -2); + lua_pushvalue(lua, 2); + lua_rawget(lua, -2); + if (!lua_isnil(lua, -1)) { + lua_pushvalue(lua, 1); + lua_pushvalue(lua, 3); + callRaw(lua, PushedObject{lua, 3}, 0); + lua_pop(lua, 2); + return 0; + } + lua_pop(lua, 2); + + // looking into default setter + lua_pushinteger(lua, 5); + lua_rawget(lua, -2); + if (lua_isnil(lua, -1)) + { + lua_pop(lua, 2); + lua_pushstring(lua, "No setter found"); + luaError(lua); + } + lua_pushvalue(lua, 1); + lua_pushvalue(lua, 2); + lua_pushvalue(lua, 3); + callRaw(lua, PushedObject{lua, 4}, 0); + lua_pop(lua, 1); + return 0; + + } catch (...) { + Pusher<std::exception_ptr>::push(lua, std::current_exception()).release(); + luaError(lua); + } + }; + + const auto toStringFunction = [](lua_State* lua) -> int { + try { + assert(lua_gettop(lua) == 1); + assert(lua_isuserdata(lua, 1)); + lua_pushstring(lua, "__tostring"); + lua_gettable(lua, 1); + if (lua_isnil(lua, -1)) + { + const void *ptr = lua_topointer(lua, -2); + lua_pop(lua, 1); + lua_pushstring(lua, (boost::format("userdata 0x%08x") % reinterpret_cast<intptr_t>(ptr)).str().c_str()); + return 1; + } + lua_pushvalue(lua, 1); + return callRaw(lua, PushedObject{lua, 2}, 1).release(); + } catch (...) { + Pusher<std::exception_ptr>::push(lua, std::current_exception()).release(); + luaError(lua); + } + }; + + + // writing structure for this type into the registry + checkTypeRegistration(state, &typeid(TType)); + + // creating the object + // lua_newuserdata allocates memory in the internals of the lua library and returns it so we can fill it + // and that's what we do with placement-new + const auto pointerLocation = static_cast<TType*>(lua_newuserdata(state, sizeof(TType))); + new (pointerLocation) TType(std::forward<TType2>(value)); + PushedObject obj{state, 1}; + + // creating the metatable (over the object on the stack) + // lua_settable pops the key and value we just pushed, so stack management is easy + // all that remains on the stack after these function calls is the metatable + lua_newtable(state); + PushedObject pushedTable{state, 1}; + + // using the garbage collecting function we created above + if (!boost::has_trivial_destructor<TType>::value) + { + lua_pushstring(state, "__gc"); + lua_pushcfunction(state, garbageCallbackFunction); + lua_settable(state, -3); + } + + // the _typeid index of the metatable will store the type_info* + lua_pushstring(state, "_typeid"); + lua_pushlightuserdata(state, const_cast<std::type_info*>(&typeid(TType))); + lua_settable(state, -3); + + // using the index function we created above + lua_pushstring(state, "__index"); + lua_pushcfunction(state, indexFunction); + lua_settable(state, -3); + + // using the newindex function we created above + lua_pushstring(state, "__newindex"); + lua_pushcfunction(state, newIndexFunction); + lua_settable(state, -3); + + lua_pushstring(state, "__tostring"); + lua_pushcfunction(state, toStringFunction); + lua_settable(state, -3); + + lua_pushstring(state, "__eq"); + lua_getglobal(state, LUACONTEXT_GLOBAL_EQ); + lua_settable(state, -3); + + + // at this point, the stack contains the object at offset -2 and the metatable at offset -1 + // lua_setmetatable will bind the two together and pop the metatable + // our custom type remains on the stack (and that's what we want since this is a push function) + lua_setmetatable(state, -2); + pushedTable.release(); + + return obj; + } + }; + + // this structure has a "size" int static member which is equal to the total of the push min size of all the types + template<typename... TTypes> + struct PusherTotalMinSize; + + // this structure has a "size" int static member which is equal to the total of the push max size of all the types + template<typename... TTypes> + struct PusherTotalMaxSize; + + // this structure has a "size" int static member which is equal to the maximum size of the push of all the types + template<typename... TTypes> + struct PusherMinSize; + + // this structure has a "size" int static member which is equal to the maximum size of the push of all the types + template<typename... TTypes> + struct PusherMaxSize; + + + /**************************************************/ + /* READ FUNCTIONS */ + /**************************************************/ + // the "Reader" structures allow to read data from the stack + // - the "ReturnType" type is what is returned by the reader, and can be different than the template parameter (especially with references and constness) + // - the "read" static function will check and read at the same time, returning an empty optional if it is the wrong type + + template<typename TType, typename = void> + struct Reader { + typedef typename std::conditional<std::is_pointer<TType>::value, TType, TType&>::type + ReturnType; + + static auto read(lua_State* state, int index) + -> boost::optional<ReturnType> + { + if (!test(state, index)) + return boost::none; + return boost::optional<ReturnType>(*static_cast<TType*>(lua_touserdata(state, index))); + } + + private: + static bool test(lua_State* state, int index) + { + if (!lua_isuserdata(state, index)) + return false; + if (!lua_getmetatable(state, index)) + return false; + + // now we have our metatable on the top of the stack + // retrieving its _typeid member + lua_pushstring(state, "_typeid"); + lua_gettable(state, -2); + const auto storedTypeID = static_cast<const std::type_info*>(lua_touserdata(state, -1)); + const auto typeIDToCompare = &typeid(TType); + + // if wrong typeid, returning false + lua_pop(state, 2); + if (storedTypeID != typeIDToCompare) + return false; + + return true; + } + }; + + /** + * This functions reads multiple values starting at "index" and passes them to the callback + */ + template<typename TRetValue, typename TCallback> + static auto readIntoFunction(lua_State* /*state*/, tag<TRetValue>, TCallback&& callback, int /*index*/) + -> TRetValue + { + return callback(); + } + template<typename TRetValue, typename TCallback, typename TFirstType, typename... TTypes> + static auto readIntoFunction(lua_State* state, tag<TRetValue> retValueTag, TCallback&& callback, int index, tag<TFirstType>, tag<TTypes>... othersTags) + -> typename std::enable_if<IsOptional<TFirstType>::value, TRetValue>::type + { + if (index >= 0) { + Binder<TCallback, const TFirstType&> binder{ callback, {} }; + return readIntoFunction(state, retValueTag, binder, index + 1, othersTags...); + } + + const auto& firstElem = Reader<typename std::decay<TFirstType>::type>::read(state, index); + if (!firstElem) + throw WrongTypeException(lua_typename(state, lua_type(state, index)), typeid(TFirstType)); + + Binder<TCallback, const TFirstType&> binder{ callback, *firstElem }; + return readIntoFunction(state, retValueTag, binder, index + 1, othersTags...); + } + template<typename TRetValue, typename TCallback, typename TFirstType, typename... TTypes> + static auto readIntoFunction(lua_State* state, tag<TRetValue> retValueTag, TCallback&& callback, int index, tag<TFirstType>, tag<TTypes>... othersTags) + -> typename std::enable_if<!IsOptional<TFirstType>::value, TRetValue>::type + { + if (index >= 0) + throw std::logic_error("Wrong number of parameters"); + + const auto& firstElem = Reader<typename std::decay<TFirstType>::type>::read(state, index); + if (!firstElem) + throw WrongTypeException(lua_typename(state, lua_type(state, index)), typeid(TFirstType)); + + Binder<TCallback, const TFirstType&> binder{ callback, *firstElem }; + return readIntoFunction(state, retValueTag, binder, index + 1, othersTags...); + } + + + /**************************************************/ + /* UTILITIES */ + /**************************************************/ + // structure that will ensure that a certain value is stored somewhere in the registry + struct ValueInRegistry { + // this constructor will clone and hold the value at the specified index (or by default at the top of the stack) in the registry + ValueInRegistry(lua_State* lua_, int index=-1) : lua{lua_} + { + lua_pushlightuserdata(lua, this); + lua_pushvalue(lua, -1 + index); + lua_settable(lua, LUA_REGISTRYINDEX); + } + + // removing the function from the registry + ~ValueInRegistry() + { + lua_pushlightuserdata(lua, this); + lua_pushnil(lua); + lua_settable(lua, LUA_REGISTRYINDEX); + } + + // loads the value and puts it at the top of the stack + PushedObject pop() + { + lua_pushlightuserdata(lua, this); + lua_gettable(lua, LUA_REGISTRYINDEX); + return PushedObject{lua, 1}; + } + + ValueInRegistry(const ValueInRegistry&) = delete; + ValueInRegistry& operator=(const ValueInRegistry&) = delete; + + private: + lua_State* lua; + }; + + // binds the first parameter of a function object + template<typename TFunctionObject, typename TFirstParamType> + struct Binder { + TFunctionObject function; + TFirstParamType param; + + template<typename... TParams> + auto operator()(TParams&&... params) + -> decltype(function(param, std::forward<TParams>(params)...)) + { + return function(param, std::forward<TParams>(params)...); + } + }; + + // turns a type into a tuple + // void is turned into std::tuple<> + // existing tuples are untouched + template<typename T> + struct Tupleizer; + + // this structure takes a pointer to a member function type and returns the base function type + template<typename TType> + struct RemoveMemberPointerFunction { typedef void type; }; // required because of a compiler bug + + // this structure takes any object and detects its function type + template<typename TObjectType> + struct FunctionTypeDetector { typedef typename RemoveMemberPointerFunction<decltype(&std::decay<TObjectType>::type::operator())>::type type; }; + + // this structure takes a function arguments list and has the "min" and the "max" static const member variables, whose value equal to the min and max number of parameters for the function + // the only case where "min != max" is with boost::optional at the end of the list + template<typename... TArgumentsList> + struct FunctionArgumentsCounter {}; + + // true is the template parameter is a boost::optional + template<typename T> + struct IsOptional : public std::false_type {}; +}; + +/// @deprecated +static LuaContext::EmptyArray_t ATTR_UNUSED + LuaEmptyArray {}; +/// @deprecated +static LuaContext::Metatable_t ATTR_UNUSED + LuaMetatable {}; + +/**************************************************/ +/* PARTIAL IMPLEMENTATIONS */ +/**************************************************/ +template<> +inline auto LuaContext::readTopAndPop<void>(lua_State* /*state*/, PushedObject /*obj*/) + -> void +{ +} + +// this structure takes a template parameter T +// if T is a tuple, it returns T ; if T is not a tuple, it returns std::tuple<T> +// we have to use this structure because std::tuple<std::tuple<...>> triggers a bug in both MSVC++ and GCC +template<typename T> +struct LuaContext::Tupleizer { typedef std::tuple<T> type; }; +template<typename... Args> +struct LuaContext::Tupleizer<std::tuple<Args...>> { typedef std::tuple<Args...> type; }; +template<> +struct LuaContext::Tupleizer<void> { typedef std::tuple<> type; }; + +// this structure takes any object and detects its function type +template<typename TRetValue, typename... TParameters> +struct LuaContext::FunctionTypeDetector<TRetValue (TParameters...)> { typedef TRetValue type(TParameters...); }; +template<typename TObjectType> +struct LuaContext::FunctionTypeDetector<TObjectType*> { typedef typename FunctionTypeDetector<TObjectType>::type type; }; + +// this structure takes a pointer to a member function type and returns the base function type +template<typename TType, typename TRetValue, typename... TParameters> +struct LuaContext::RemoveMemberPointerFunction<TRetValue (TType::*)(TParameters...)> { typedef TRetValue type(TParameters...); }; +template<typename TType, typename TRetValue, typename... TParameters> +struct LuaContext::RemoveMemberPointerFunction<TRetValue (TType::*)(TParameters...) const> { typedef TRetValue type(TParameters...); }; +template<typename TType, typename TRetValue, typename... TParameters> +struct LuaContext::RemoveMemberPointerFunction<TRetValue (TType::*)(TParameters...) volatile> { typedef TRetValue type(TParameters...); }; +template<typename TType, typename TRetValue, typename... TParameters> +struct LuaContext::RemoveMemberPointerFunction<TRetValue (TType::*)(TParameters...) const volatile> { typedef TRetValue type(TParameters...); }; + +// implementation of PusherTotalMinSize +template<typename TFirst, typename... TTypes> +struct LuaContext::PusherTotalMinSize<TFirst, TTypes...> { static const int size = Pusher<typename std::decay<TFirst>::type>::minSize + PusherTotalMinSize<TTypes...>::size; }; +template<> +struct LuaContext::PusherTotalMinSize<> { static const int size = 0; }; + +// implementation of PusherTotalMaxSize +template<typename TFirst, typename... TTypes> +struct LuaContext::PusherTotalMaxSize<TFirst, TTypes...> { static const int size = Pusher<typename std::decay<TFirst>::type>::maxSize + PusherTotalMaxSize<TTypes...>::size; }; +template<> +struct LuaContext::PusherTotalMaxSize<> { static const int size = 0; }; + +// implementation of PusherMinSize +template<typename TFirst, typename TSecond, typename... TTypes> +struct LuaContext::PusherMinSize<TFirst, TSecond, TTypes...> +{ + static const int size = Pusher<typename std::decay<TFirst>::type>::minSize < Pusher<typename std::decay<TSecond>::type>::minSize + ? + PusherMinSize<typename std::decay<TFirst>::type, TTypes...>::size + : + PusherMinSize<typename std::decay<TSecond>::type, TTypes...>::size; +}; + +template<typename TFirst> +struct LuaContext::PusherMinSize<TFirst> { static const int size = Pusher<typename std::decay<TFirst>::type>::minSize; }; + +// implementation of PusherMaxSize +template<typename TFirst, typename... TTypes> +struct LuaContext::PusherMaxSize<TFirst, TTypes...> { static const int size = Pusher<typename std::decay<TFirst>::type>::maxSize > PusherTotalMaxSize<TTypes...>::size ? Pusher<typename std::decay<TFirst>::type>::maxSize : PusherMaxSize<TTypes...>::size; }; +template<> +struct LuaContext::PusherMaxSize<> { static const int size = 0; }; + +// implementation of FunctionArgumentsCounter +template<typename TFirst, typename... TParams> +struct LuaContext::FunctionArgumentsCounter<TFirst, TParams...> { + typedef FunctionArgumentsCounter<TParams...> + SubType; + static const int min = (IsOptional<TFirst>::value && SubType::min == 0) ? 0 : 1 + SubType::min; + static const int max = 1 + SubType::max; +}; +template<> +struct LuaContext::FunctionArgumentsCounter<> { + static const int min = 0; + static const int max = 0; +}; + +// implementation of IsOptional +template<typename T> +struct LuaContext::IsOptional<boost::optional<T>> : public std::true_type {}; + +// implementation of LuaFunctionCaller +template<typename TFunctionType> +class LuaContext::LuaFunctionCaller { static_assert(std::is_function<TFunctionType>::value, "Template parameter of LuaFunctionCaller must be a function type"); }; +template<typename TRetValue, typename... TParams> +class LuaContext::LuaFunctionCaller<TRetValue (TParams...)> +{ +public: + TRetValue operator()(TParams&&... params) const + { + auto obj = valueHolder->pop(); + return call<TRetValue>(state, std::move(obj), std::forward<TParams>(params)...); + } + +private: + std::shared_ptr<ValueInRegistry> valueHolder; + lua_State* state; + +private: + friend LuaContext; + explicit LuaFunctionCaller(lua_State* state_, int index) : + valueHolder(std::make_shared<ValueInRegistry>(state_, index)), + state(state_) + {} +}; + + +/**************************************************/ +/* PUSH FUNCTIONS */ +/**************************************************/ +// specializations of the Pusher structure + +// opaque Lua references +template<> +struct LuaContext::Pusher<LuaContext::LuaObject> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, const LuaContext::LuaObject& value) noexcept { + if (value.objectInRegistry.get()) { + PushedObject obj = value.objectInRegistry->pop(); + return obj; + } else { + lua_pushnil(state); + return PushedObject{state, 1}; + } + } +}; + +// boolean +template<> +struct LuaContext::Pusher<bool> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, bool value) noexcept { + lua_pushboolean(state, value); + return PushedObject{state, 1}; + } +}; + +// string +template<> +struct LuaContext::Pusher<std::string> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, const std::string& value) noexcept { + lua_pushlstring(state, value.c_str(), value.length()); + return PushedObject{state, 1}; + } +}; + +// const char* +template<> +struct LuaContext::Pusher<const char*> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, const char* value) noexcept { + lua_pushstring(state, value); + return PushedObject{state, 1}; + } +}; + +// const char[N] +template<int N> +struct LuaContext::Pusher<const char[N]> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, const char* value) noexcept { + lua_pushstring(state, value); + return PushedObject{state, 1}; + } +}; + +// floating numbers +template<typename T> +struct LuaContext::Pusher<T, typename std::enable_if<std::is_floating_point<T>::value>::type> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, T value) noexcept { + lua_pushnumber(state, value); + return PushedObject{state, 1}; + } +}; + +// integers +template<typename T> +struct LuaContext::Pusher<T, typename std::enable_if<std::is_integral<T>::value>::type> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, T value) noexcept { + lua_pushinteger(state, value); + return PushedObject{state, 1}; + } +}; + +// nil +template<> +struct LuaContext::Pusher<std::nullptr_t> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, std::nullptr_t) noexcept { + lua_pushnil(state); + return PushedObject{state, 1}; + } +}; + +// empty arrays +template<> +struct LuaContext::Pusher<LuaContext::EmptyArray_t> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, EmptyArray_t) noexcept { + lua_newtable(state); + return PushedObject{state, 1}; + } +}; + +// std::type_info* is a lightuserdata +template<> +struct LuaContext::Pusher<const std::type_info*> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, const std::type_info* ptr) noexcept { + lua_pushlightuserdata(state, const_cast<std::type_info*>(ptr)); + return PushedObject{state, 1}; + } +}; + +// thread +template<> +struct LuaContext::Pusher<LuaContext::ThreadID> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, const LuaContext::ThreadID& value) noexcept { + lua_pushthread(value.state); + return PushedObject{state, 1}; + } +}; + +// maps +template<typename TKey, typename TValue> +struct LuaContext::Pusher<std::map<TKey,TValue>> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, const std::map<TKey,TValue>& value) noexcept { + static_assert(Pusher<typename std::decay<TKey>::type>::minSize == 1 && Pusher<typename std::decay<TKey>::type>::maxSize == 1, "Can't push multiple elements for a table key"); + static_assert(Pusher<typename std::decay<TValue>::type>::minSize == 1 && Pusher<typename std::decay<TValue>::type>::maxSize == 1, "Can't push multiple elements for a table value"); + + auto obj = Pusher<EmptyArray_t>::push(state, EmptyArray); + + for (auto i = value.begin(), e = value.end(); i != e; ++i) + setTable<TValue>(state, obj, i->first, i->second); + + return obj; + } +}; + +// unordered_maps +template<typename TKey, typename TValue, typename THash, typename TKeyEqual> +struct LuaContext::Pusher<std::unordered_map<TKey,TValue,THash,TKeyEqual>> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, const std::unordered_map<TKey,TValue,THash,TKeyEqual>& value) noexcept { + static_assert(Pusher<typename std::decay<TKey>::type>::minSize == 1 && Pusher<typename std::decay<TKey>::type>::maxSize == 1, "Can't push multiple elements for a table key"); + static_assert(Pusher<typename std::decay<TValue>::type>::minSize == 1 && Pusher<typename std::decay<TValue>::type>::maxSize == 1, "Can't push multiple elements for a table value"); + + auto obj = Pusher<EmptyArray_t>::push(state, EmptyArray); + + for (auto i = value.begin(), e = value.end(); i != e; ++i) + setTable<TValue>(state, obj, i->first, i->second); + + return obj; + } +}; + +// vectors of pairs +template<typename TType1, typename TType2> +struct LuaContext::Pusher<std::vector<std::pair<TType1,TType2>>> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, const std::vector<std::pair<TType1,TType2>>& value) noexcept { + static_assert(Pusher<typename std::decay<TType1>::type>::minSize == 1 && Pusher<typename std::decay<TType1>::type>::maxSize == 1, "Can't push multiple elements for a table key"); + static_assert(Pusher<typename std::decay<TType2>::type>::minSize == 1 && Pusher<typename std::decay<TType2>::type>::maxSize == 1, "Can't push multiple elements for a table value"); + + auto obj = Pusher<EmptyArray_t>::push(state, EmptyArray); + + for (auto i = value.begin(), e = value.end(); i != e; ++i) + setTable<TType2>(state, obj, i->first, i->second); + + return obj; + } +}; + +// vectors +template<typename TType> +struct LuaContext::Pusher<std::vector<TType>> { + static const int minSize = 1; + static const int maxSize = 1; + + static PushedObject push(lua_State* state, const std::vector<TType>& value) noexcept { + static_assert(Pusher<typename std::decay<TType>::type>::minSize == 1 && Pusher<typename std::decay<TType>::type>::maxSize == 1, "Can't push multiple elements for a table value"); + + auto obj = Pusher<EmptyArray_t>::push(state, EmptyArray); + + for (unsigned int i = 0; i < value.size(); ++i) + setTable<TType>(state, obj, i + 1, value[i]); + + return obj; + } +}; + +// unique_ptr +template<typename TType> +struct LuaContext::Pusher<std::unique_ptr<TType>> { + static const int minSize = Pusher<std::shared_ptr<TType>>::minSize; + static const int maxSize = Pusher<std::shared_ptr<TType>>::maxSize; + + static PushedObject push(lua_State* state, std::unique_ptr<TType> value) noexcept { + return Pusher<std::shared_ptr<TType>>::push(state, std::move(value)); + } +}; + +// enum +template<typename TEnum> +struct LuaContext::Pusher<TEnum, typename std::enable_if<std::is_enum<TEnum>::value>::type> { + #if !defined(__clang__) || __clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ > 3) + typedef typename std::underlying_type<TEnum>::type + RealType; + #else + // implementation when std::underlying_type is not supported + typedef unsigned long + RealType; + #endif + + static const int minSize = Pusher<RealType>::minSize; + static const int maxSize = Pusher<RealType>::maxSize; + + static PushedObject push(lua_State* state, TEnum value) noexcept { + return Pusher<RealType>::push(state, static_cast<RealType>(value)); + } +}; + +// any function +// this specialization is not directly called, but is called by other specializations +template<typename TReturnType, typename... TParameters> +struct LuaContext::Pusher<TReturnType (TParameters...)> +{ + static const int minSize = 1; + static const int maxSize = 1; + + // counts the number of arguments + typedef FunctionArgumentsCounter<TParameters...> + LocalFunctionArgumentsCounter; + + // this is the version of "push" for non-trivially destructible function objects + template<typename TFunctionObject> + static auto push(lua_State* state, TFunctionObject fn) noexcept + -> typename std::enable_if<!boost::has_trivial_destructor<TFunctionObject>::value, PushedObject>::type + { + // TODO: is_move_constructible not supported by some compilers + //static_assert(std::is_move_constructible<TFunctionObject>::value, "The function object must be move-constructible"); + + // when the lua script calls the thing we will push on the stack, we want "fn" to be executed + // if we used lua's cfunctions system, we could not detect when the function is no longer in use, which could cause problems + // so we use userdata instead + + // this function is called when the lua script tries to call our custom data type + // we transfer execution to the "callback" function below + const auto callCallback = [](lua_State* lua) -> int { + assert(lua_gettop(lua) >= 1); + assert(lua_isuserdata(lua, 1)); + auto function = static_cast<TFunctionObject*>(lua_touserdata(lua, 1)); + assert(function); + + return callback(lua, function, lua_gettop(lua) - 1).release(); + }; + + // this one is called when lua's garbage collector no longer needs our custom data type + // we call the function object's destructor + const auto garbageCallback = [](lua_State* lua) -> int { + assert(lua_gettop(lua) == 1); + auto function = static_cast<TFunctionObject*>(lua_touserdata(lua, 1)); + assert(function); + function->~TFunctionObject(); + return 0; + }; + + // creating the object + // lua_newuserdata allocates memory in the internals of the lua library and returns it so we can fill it + // and that's what we do with placement-new + const auto functionLocation = static_cast<TFunctionObject*>(lua_newuserdata(state, sizeof(TFunctionObject))); + new (functionLocation) TFunctionObject(std::move(fn)); + + // creating the metatable (over the object on the stack) + // lua_settable pops the key and value we just pushed, so stack management is easy + // all that remains on the stack after these function calls is the metatable + lua_newtable(state); + lua_pushstring(state, "__call"); + lua_pushcfunction(state, callCallback); + lua_settable(state, -3); + + lua_pushstring(state, "__gc"); + lua_pushcfunction(state, garbageCallback); + lua_settable(state, -3); + + // at this point, the stack contains the object at offset -2 and the metatable at offset -1 + // lua_setmetatable will bind the two together and pop the metatable + // our custom function remains on the stack (and that's what we want) + lua_setmetatable(state, -2); + + return PushedObject{state, 1}; + } + + // this is the version of "push" for trivially destructible objects + template<typename TFunctionObject> + static auto push(lua_State* state, TFunctionObject fn) noexcept + -> typename std::enable_if<boost::has_trivial_destructor<TFunctionObject>::value, PushedObject>::type + { + // TODO: is_move_constructible not supported by some compilers + //static_assert(std::is_move_constructible<TFunctionObject>::value, "The function object must be move-constructible"); + + // when the lua script calls the thing we will push on the stack, we want "fn" to be executed + // since "fn" doesn't need to be destroyed, we simply push it on the stack + + // this is the cfunction that is the callback + const auto function = [](lua_State* state_) -> int + { + // the function object is an upvalue + const auto toCall = static_cast<TFunctionObject*>(lua_touserdata(state_, lua_upvalueindex(1))); + return callback(state_, toCall, lua_gettop(state_)).release(); + }; + + // we copy the function object onto the stack + const auto functionObjectLocation = static_cast<TFunctionObject*>(lua_newuserdata(state, sizeof(TFunctionObject))); + new (functionObjectLocation) TFunctionObject(std::move(fn)); + + // pushing the function with the function object as upvalue + lua_pushcclosure(state, function, 1); + return PushedObject{state, 1}; + } + + // this is the version of "push" for pointer to functions + static auto push(lua_State* state, TReturnType (*fn)(TParameters...)) noexcept + -> PushedObject + { + // when the lua script calls the thing we will push on the stack, we want "fn" to be executed + // since "fn" doesn't need to be destroyed, we simply push it on the stack + + // this is the cfunction that is the callback + const auto function = [](lua_State* state_) -> int + { + // the function object is an upvalue + const auto toCall = reinterpret_cast<TReturnType (*)(TParameters...)>(lua_touserdata(state_, lua_upvalueindex(1))); + return callback(state_, toCall, lua_gettop(state_)).release(); + }; + + // we copy the function object onto the stack + lua_pushlightuserdata(state, reinterpret_cast<void*>(fn)); + + // pushing the function with the function object as upvalue + lua_pushcclosure(state, function, 1); + return PushedObject{state, 1}; + } + + // this is the version of "push" for references to functions + static auto push(lua_State* state, TReturnType (&fn)(TParameters...)) noexcept + -> PushedObject + { + return push(state, &fn); + } + +private: + // callback that calls the function object + // this function is used by the callbacks and handles loading arguments from the stack and pushing the return value back + template<typename TFunctionObject> + static auto callback(lua_State* state, TFunctionObject* toCall, int argumentsCount) + -> PushedObject + { + // checking if number of parameters is correct + if (argumentsCount < LocalFunctionArgumentsCounter::min) { + // if not, using lua_error to return an error + luaL_where(state, 1); + lua_pushstring(state, "This function requires at least "); + lua_pushnumber(state, LocalFunctionArgumentsCounter::min); + lua_pushstring(state, " parameter(s)"); + lua_concat(state, 4); + luaError(state); + + } else if (argumentsCount > LocalFunctionArgumentsCounter::max) { + // if not, using lua_error to return an error + luaL_where(state, 1); + lua_pushstring(state, "This function requires at most "); + lua_pushnumber(state, LocalFunctionArgumentsCounter::max); + lua_pushstring(state, " parameter(s)"); + lua_concat(state, 4); + luaError(state); + } + + // calling the function + try { + return callback2(state, *toCall, argumentsCount); + + } catch (const WrongTypeException& ex) { + // wrong parameter type, using lua_error to return an error + luaL_where(state, 1); + lua_pushstring(state, "Unable to convert parameter from "); + lua_pushstring(state, ex.luaType.c_str()); + lua_pushstring(state, " to "); + lua_pushstring(state, ex.destination.name()); + lua_concat(state, 5); + luaError(state); + + } catch (const std::exception& e) { + luaL_where(state, 1); + lua_pushstring(state, "Caught exception: "); + lua_pushstring(state, e.what()); + lua_concat(state, 3); + luaError(state); + } catch (...) { + Pusher<std::exception_ptr>::push(state, std::current_exception()).release(); + luaError(state); + } + } + + template<typename TFunctionObject> + static auto callback2(lua_State* state, TFunctionObject&& toCall, int argumentsCount) + -> typename std::enable_if<!std::is_void<TReturnType>::value && !std::is_void<TFunctionObject>::value, PushedObject>::type + { + // pushing the result on the stack and returning number of pushed elements + typedef Pusher<typename std::decay<TReturnType>::type> + P; + return P::push(state, readIntoFunction(state, tag<TReturnType>{}, toCall, -argumentsCount, tag<TParameters>{}...)); + } + + template<typename TFunctionObject> + static auto callback2(lua_State* state, TFunctionObject&& toCall, int argumentsCount) + -> typename std::enable_if<std::is_void<TReturnType>::value && !std::is_void<TFunctionObject>::value, PushedObject>::type + { + readIntoFunction(state, tag<TReturnType>{}, toCall, -argumentsCount, tag<TParameters>{}...); + return PushedObject{state, 0}; + } +}; + +// C function pointers +template<typename TReturnType, typename... TParameters> +struct LuaContext::Pusher<TReturnType (*)(TParameters...)> +{ + // using the function-pushing implementation + typedef Pusher<TReturnType (TParameters...)> + SubPusher; + static const int minSize = SubPusher::minSize; + static const int maxSize = SubPusher::maxSize; + + template<typename TType> + static PushedObject push(lua_State* state, TType value) noexcept { + return SubPusher::push(state, value); + } +}; + +// C function references +template<typename TReturnType, typename... TParameters> +struct LuaContext::Pusher<TReturnType (&)(TParameters...)> +{ + // using the function-pushing implementation + typedef Pusher<TReturnType(TParameters...)> + SubPusher; + static const int minSize = SubPusher::minSize; + static const int maxSize = SubPusher::maxSize; + + template<typename TType> + static PushedObject push(lua_State* state, TType value) noexcept { + return SubPusher::push(state, value); + } +}; + +// std::function +template<typename TReturnType, typename... TParameters> +struct LuaContext::Pusher<std::function<TReturnType (TParameters...)>> +{ + // using the function-pushing implementation + typedef Pusher<TReturnType (TParameters...)> + SubPusher; + static const int minSize = SubPusher::minSize; + static const int maxSize = SubPusher::maxSize; + + static PushedObject push(lua_State* state, const std::function<TReturnType (TParameters...)>& value) noexcept { + return SubPusher::push(state, value); + } +}; + +// boost::variant +template<typename... TTypes> +struct LuaContext::Pusher<boost::variant<TTypes...>> +{ + static const int minSize = PusherMinSize<TTypes...>::size; + static const int maxSize = PusherMaxSize<TTypes...>::size; + + static PushedObject push(lua_State* state, const boost::variant<TTypes...>& value) noexcept { + PushedObject obj{state, 0}; + VariantWriter writer{state, obj}; + value.apply_visitor(writer); + return obj; + } + +private: + struct VariantWriter : public boost::static_visitor<> { + template<typename TType> + void operator()(TType value) noexcept + { + obj = Pusher<typename std::decay<TType>::type>::push(state, std::move(value)); + } + + VariantWriter(lua_State* state_, PushedObject& obj_) : state(state_), obj(obj_) {} + lua_State* state; + PushedObject& obj; + }; +}; + +// boost::optional +template<typename TType> +struct LuaContext::Pusher<boost::optional<TType>> { + typedef Pusher<typename std::decay<TType>::type> + UnderlyingPusher; + + static const int minSize = UnderlyingPusher::minSize < 1 ? UnderlyingPusher::minSize : 1; + static const int maxSize = UnderlyingPusher::maxSize > 1 ? UnderlyingPusher::maxSize : 1; + + static PushedObject push(lua_State* state, const boost::optional<TType>& value) noexcept { + if (value) { + return UnderlyingPusher::push(state, value.get()); + } else { + lua_pushnil(state); + return PushedObject{state, 1}; + } + } +}; + +// tuple +template<typename... TTypes> +struct LuaContext::Pusher<std::tuple<TTypes...>> { + // TODO: NOT EXCEPTION SAFE /!\ // + static const int minSize = PusherTotalMinSize<TTypes...>::size; + static const int maxSize = PusherTotalMaxSize<TTypes...>::size; + + static PushedObject push(lua_State* state, const std::tuple<TTypes...>& value) noexcept { + return PushedObject{state, push2(state, value, std::integral_constant<int,0>{})}; + } + + static PushedObject push(lua_State* state, std::tuple<TTypes...>&& value) noexcept { + return PushedObject{state, push2(state, std::move(value), std::integral_constant<int,0>{})}; + } + +private: + template<int N> + static int push2(lua_State* state, const std::tuple<TTypes...>& value, std::integral_constant<int,N>) noexcept { + typedef typename std::tuple_element<N,std::tuple<TTypes...>>::type ElemType; + + return Pusher<typename std::decay<ElemType>::type>::push(state, std::get<N>(value)).release() + + push2(state, value, std::integral_constant<int,N+1>{}); + } + + template<int N> + static int push2(lua_State* state, std::tuple<TTypes...>&& value, std::integral_constant<int,N>) noexcept { + typedef typename std::tuple_element<N,std::tuple<TTypes...>>::type ElemType; + + return Pusher<typename std::decay<ElemType>::type>::push(state, std::move(std::get<N>(value))).release() + + push2(state, std::move(value), std::integral_constant<int,N+1>{}); + } + + static int push2(lua_State* /*state*/, const std::tuple<TTypes...>&, std::integral_constant<int,sizeof...(TTypes)>) noexcept { + return 0; + } + + static int push2(lua_State* /*state*/, std::tuple<TTypes...>&&, std::integral_constant<int,sizeof...(TTypes)>) noexcept { + return 0; + } +}; + +/**************************************************/ +/* READ FUNCTIONS */ +/**************************************************/ +// specializations of the Reader structures + +// opaque Lua references +template<> +struct LuaContext::Reader<LuaContext::LuaObject> +{ + static auto read(lua_State* state, int index) + -> boost::optional<LuaContext::LuaObject> + { + LuaContext::LuaObject obj(state, index); + return obj; + } +}; + +// reading null +template<> +struct LuaContext::Reader<std::nullptr_t> +{ + static auto read(lua_State* state, int index) + -> boost::optional<std::nullptr_t> + { + if (!lua_isnil(state, index)) + return boost::none; + return nullptr; + } +}; + +// integrals +template<typename TType> +struct LuaContext::Reader< + TType, + typename std::enable_if<std::is_integral<TType>::value>::type + > +{ + static auto read(lua_State* state, int index) + -> boost::optional<TType> + { +# if LUA_VERSION_NUM >= 502 + + int success; + auto value = lua_tointegerx(state, index, &success); + if (success == 0) + return boost::none; + return static_cast<TType>(value); + +# else + + if (!lua_isnumber(state, index)) + return boost::none; + return static_cast<TType>(lua_tointeger(state, index)); + +# endif + } +}; + +// floating points +template<typename TType> +struct LuaContext::Reader< + TType, + typename std::enable_if<std::is_floating_point<TType>::value>::type + > +{ + static auto read(lua_State* state, int index) + -> boost::optional<TType> + { +# if LUA_VERSION_NUM >= 502 + + int success; + auto value = lua_tonumberx(state, index, &success); + if (success == 0) + return boost::none; + return static_cast<TType>(value); + +# else + + if (!lua_isnumber(state, index)) + return boost::none; + return static_cast<TType>(lua_tonumber(state, index)); + +# endif + } +}; + +// boolean +template<> +struct LuaContext::Reader<bool> +{ + static auto read(lua_State* state, int index) + -> boost::optional<bool> + { + if (!lua_isboolean(state, index)) + return boost::none; + return lua_toboolean(state, index) != 0; + } +}; + +// string +// lua_tostring returns a temporary pointer, but that's not a problem since we copy +// the data into a std::string +template<> +struct LuaContext::Reader<std::string> +{ + static auto read(lua_State* state, int index) + -> boost::optional<std::string> + { + std::string result; + + // lua_tolstring might convert the variable that would confuse lua_next, so we + // make a copy of the variable. + lua_pushvalue(state, index); + + size_t len; + const auto val = lua_tolstring(state, -1, &len); + + if (val != nullptr) + result.assign(val, len); + + lua_pop(state, 1); + + return val != nullptr ? boost::optional<std::string>{ std::move(result) } : boost::none; + } +}; + +// enums +template<typename TType> +struct LuaContext::Reader< + TType, + typename std::enable_if<std::is_enum<TType>::value>::type + > +{ + static auto read(lua_State* state, int index) + -> boost::optional<TType> + { + if (!lua_isnumber(state, index) || fmod(lua_tonumber(state, index), 1.) != 0) + return boost::none; + return static_cast<TType>(lua_tointeger(state, index)); + } +}; + +// LuaFunctionCaller +template<typename TRetValue, typename... TParameters> +struct LuaContext::Reader<LuaContext::LuaFunctionCaller<TRetValue (TParameters...)>> +{ + typedef LuaFunctionCaller<TRetValue (TParameters...)> + ReturnType; + + static auto read(lua_State* state, int index) + -> boost::optional<ReturnType> + { + if (lua_isfunction(state, index) == 0 && lua_isuserdata(state, index) == 0) + return boost::none; + return ReturnType(state, index); + } +}; + +// function +template<typename TRetValue, typename... TParameters> +struct LuaContext::Reader<std::function<TRetValue (TParameters...)>> +{ + static auto read(lua_State* state, int index) + -> boost::optional<std::function<TRetValue (TParameters...)>> + { + if (auto val = Reader<LuaContext::LuaFunctionCaller<TRetValue (TParameters...)>>::read(state, index)) + { + std::function<TRetValue (TParameters...)> f{*val}; + return boost::optional<std::function<TRetValue (TParameters...)>>{std::move(f)}; + } + + return boost::none; + } +}; + +// vector of pairs +template<typename TType1, typename TType2> +struct LuaContext::Reader<std::vector<std::pair<TType1,TType2>>> +{ + static auto read(lua_State* state, int index) + -> boost::optional<std::vector<std::pair<TType1, TType2>>> + { + if (!lua_istable(state, index)) + return boost::none; + + std::vector<std::pair<TType1, TType2>> result; + + // we traverse the table at the top of the stack + lua_pushnil(state); // first key + while (lua_next(state, (index > 0) ? index : (index - 1)) != 0) { + // now a key and its value are pushed on the stack + try { + auto val1 = Reader<TType1>::read(state, -2); + auto val2 = Reader<TType2>::read(state, -1); + + if (!val1.is_initialized() || !val2.is_initialized()) { + lua_pop(state, 2); // we remove the value and the key + return {}; + } + + result.push_back({ val1.get(), val2.get() }); + lua_pop(state, 1); // we remove the value but keep the key for the next iteration + + } catch(...) { + lua_pop(state, 2); // we remove the value and the key + return {}; + } + } + + return { std::move(result) }; + } +}; + +// map +template<typename TKey, typename TValue> +struct LuaContext::Reader<std::map<TKey,TValue>> +{ + static auto read(lua_State* state, int index) + -> boost::optional<std::map<TKey,TValue>> + { + if (!lua_istable(state, index)) + return boost::none; + + std::map<TKey,TValue> result; + + // we traverse the table at the top of the stack + lua_pushnil(state); // first key + while (lua_next(state, (index > 0) ? index : (index - 1)) != 0) { + // now a key and its value are pushed on the stack + try { + auto key = Reader<TKey>::read(state, -2); + auto value = Reader<TValue>::read(state, -1); + + if (!key.is_initialized() || !value.is_initialized()) { + lua_pop(state, 2); // we remove the value and the key + return {}; + } + + result.insert({ key.get(), value.get() }); + lua_pop(state, 1); // we remove the value but keep the key for the next iteration + + } catch(...) { + lua_pop(state, 2); // we remove the value and the key + return {}; + } + } + + return { std::move(result) }; + } +}; + +// unordered_map +template<typename TKey, typename TValue, typename THash, typename TKeyEqual> +struct LuaContext::Reader<std::unordered_map<TKey,TValue,THash,TKeyEqual>> +{ + static auto read(lua_State* state, int index) + -> boost::optional<std::unordered_map<TKey,TValue,THash,TKeyEqual>> + { + if (!lua_istable(state, index)) + return boost::none; + + std::unordered_map<TKey,TValue,THash,TKeyEqual> result; + + // we traverse the table at the top of the stack + lua_pushnil(state); // first key + while (lua_next(state, (index > 0) ? index : (index - 1)) != 0) { + // now a key and its value are pushed on the stack + try { + auto key = Reader<TKey>::read(state, -2); + auto value = Reader<TValue>::read(state, -1); + + if (!key.is_initialized() || !value.is_initialized()) { + lua_pop(state, 2); // we remove the value and the key + return {}; + } + + result.insert({ key.get(), value.get() }); + lua_pop(state, 1); // we remove the value but keep the key for the next iteration + + } catch(...) { + lua_pop(state, 2); // we remove the value and the key + return {}; + } + } + + return { std::move(result) }; + } +}; + +// optional +// IMPORTANT: optional means "either nil or the value of the right type" +// * if the value is nil, then an optional containing an empty optional is returned +// * if the value is of the right type, then an optional containing an optional containing the value is returned +// * if the value is of the wrong type, then an empty optional is returned +template<typename TType> +struct LuaContext::Reader<boost::optional<TType>> +{ + static auto read(lua_State* state, int index) + -> boost::optional<boost::optional<TType>> + { + if (lua_isnil(state, index)) + return boost::optional<TType>{boost::none}; + if (auto&& other = Reader<TType>::read(state, index)) + return std::move(other); + return boost::none; + } +}; + +// variant +template<typename... TTypes> +struct LuaContext::Reader<boost::variant<TTypes...>> +{ + typedef boost::variant<TTypes...> + ReturnType; + +private: + // class doing operations for a range of types from TIterBegin to TIterEnd + template<typename TIterBegin, typename TIterEnd, typename = void> + struct VariantReader + { + using SubReader = Reader<typename std::decay<typename boost::mpl::deref<TIterBegin>::type>::type>; + + static auto read(lua_State* state, int index) + -> boost::optional<ReturnType> + { + // note: using SubReader::read triggers a compilation error when used with a reference + if (const auto val = SubReader::read(state, index)) + return boost::variant<TTypes...>{*val}; + return VariantReader<typename boost::mpl::next<TIterBegin>::type, TIterEnd>::read(state, index); + } + }; + + // specialization of class above being called when list of remaining types is empty + template<typename TIterBegin, typename TIterEnd> + struct VariantReader<TIterBegin, TIterEnd, typename std::enable_if<boost::mpl::distance<TIterBegin, TIterEnd>::type::value == 0>::type> + { + static auto read(lua_State* /*state*/, int /*index*/) + -> boost::optional<ReturnType> + { + return boost::none; + } + }; + + // this is the main type + typedef VariantReader<typename boost::mpl::begin<typename ReturnType::types>::type, typename boost::mpl::end<typename ReturnType::types>::type> + MainVariantReader; + +public: + static auto read(lua_State* state, int index) + -> boost::optional<ReturnType> + { + return MainVariantReader::read(state, index); + } +}; + +// reading a tuple +// tuple have an additional argument for their functions, that is the maximum size to read +// if maxSize is smaller than the tuple size, then the remaining parameters will be left to default value +template<> +struct LuaContext::Reader<std::tuple<>> +{ + static auto read(lua_State* /*state*/, int /*index*/, int /*maxSize*/ = 0) + -> boost::optional<std::tuple<>> + { + return std::tuple<>{}; + } +}; + +template<typename TFirst, typename... TOthers> +struct LuaContext::Reader<std::tuple<TFirst, TOthers...>, + typename std::enable_if<!LuaContext::IsOptional<TFirst>::value>::type // TODO: replace by std::is_default_constructible when it works on every compiler + > +{ + // this is the "TFirst is NOT default constructible" version + + typedef std::tuple<TFirst, TOthers...> + ReturnType; + + static auto read(lua_State* state, int index, int maxSize = std::tuple_size<ReturnType>::value) + -> boost::optional<ReturnType> + { + if (maxSize <= 0) + return boost::none; + + auto firstVal = Reader<TFirst>::read(state, index); + auto othersVal = Reader<std::tuple<TOthers...>>::read(state, index + 1, maxSize - 1); + + if (!firstVal || !othersVal) + return boost::none; + + return std::tuple_cat(std::tuple<TFirst>(*firstVal), std::move(*othersVal)); + } +}; + +template<typename TFirst, typename... TOthers> +struct LuaContext::Reader<std::tuple<TFirst, TOthers...>, + typename std::enable_if<LuaContext::IsOptional<TFirst>::value>::type // TODO: replace by std::is_default_constructible when it works on every compiler + > +{ + // this is the "TFirst is default-constructible" version + + typedef std::tuple<TFirst, TOthers...> + ReturnType; + + static auto read(lua_State* state, int index, int maxSize = std::tuple_size<ReturnType>::value) + -> boost::optional<ReturnType> + { + auto othersVal = Reader<std::tuple<TOthers...>>::read(state, index + 1, maxSize - 1); + if (!othersVal) + return boost::none; + + if (maxSize <= 0) + return std::tuple_cat(std::tuple<TFirst>(), std::move(*othersVal)); + + auto firstVal = Reader<TFirst>::read(state, index); + if (!firstVal) + return boost::none; + + return std::tuple_cat(std::tuple<TFirst>(*firstVal), std::move(*othersVal)); + } +}; + +#if defined(__GNUC__) && !defined(__clang__) +#pragma GCC diagnostic pop +#endif + +#endif |