Add coroutine support (WIP)

src/Nazara/Lua/LuaCoroutine.cpp

@@ -0,0 +1,55 @@
+// Copyright (C) 2017 Jérôme Leclercq
+// This file is part of the "Nazara Engine - Lua scripting module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Lua/LuaCoroutine.hpp>
+#include <Lua/lauxlib.h>
+#include <Lua/lua.h>
+#include <Lua/lualib.h>
+#include <Nazara/Lua/Debug.hpp>
+
+namespace Nz
+{
+	LuaCoroutine::LuaCoroutine(lua_State* internalState, int refIndex) :
+	LuaState(internalState),
+	m_ref(refIndex)
+	{
+	}
+
+	LuaCoroutine::~LuaCoroutine()
+	{
+		if (m_ref >= 0)
+			DestroyReference(m_ref);
+	}
+
+	bool LuaCoroutine::CanResume() const
+	{
+		return lua_status(m_state) == LUA_YIELD;
+	}
+
+	Ternary LuaCoroutine::Resume(unsigned int argCount)
+	{
+		LuaInstance& instance = GetInstance(m_state);
+		if (instance.m_level++ == 0)
+			instance.m_clock.Restart();
+
+		int status = lua_resume(m_state, nullptr, argCount);
+		instance.m_level--;
+
+		if (status == LUA_OK)
+			return Ternary_True;
+		else if (status == LUA_YIELD)
+			return Ternary_Unknown;
+		else
+		{
+			m_lastError = ToString(-1);
+			Pop();
+			return Ternary_False;
+		}
+	}
+
+	bool LuaCoroutine::Run(int argCount, int /*resultCount*/)
+	{
+		return Resume(argCount) != Ternary_False;
+	}
+}

src/Nazara/Lua/LuaInstance.cpp

@@ -30,7 +30,7 @@ namespace Nz
 	}
 
 	LuaInstance::LuaInstance() :
-	LuaState(this, lua_newstate(MemoryAllocator, this)),
+	LuaState(nullptr),
 	m_memoryLimit(0),
 	m_memoryUsage(0),
 	m_timeLimit(1000),

src/Nazara/Lua/LuaState.cpp

@@ -12,6 +12,7 @@
 #include <Nazara/Core/MemoryHelper.hpp>
 #include <Nazara/Core/MemoryView.hpp>
 #include <Nazara/Core/StringStream.hpp>
+#include <Nazara/Lua/LuaCoroutine.hpp>
 #include <Nazara/Lua/LuaInstance.hpp>
 #include <cstdlib>
 #include <stdexcept>
@@ -127,7 +128,6 @@ namespace Nz
 
 	LuaState::LuaState(LuaState&& state) noexcept :
 	m_lastError(state.m_lastError),
-	m_instance(state.m_instance),
 	m_state(state.m_state)
 	{
 	}
@@ -570,6 +570,14 @@ namespace Nz
 		lua_xmove(m_state, instance->m_state, n);
 	}
 
+	LuaCoroutine LuaState::NewCoroutine()
+	{
+		lua_State* thread = lua_newthread(m_state);
+		int ref = luaL_ref(m_state, LUA_REGISTRYINDEX);
+
+		return LuaCoroutine(thread, ref);
+	}
+
 	bool LuaState::NewMetatable(const char* str)
 	{
 		return luaL_newmetatable(m_state, str) != 0;
@@ -783,7 +791,6 @@ namespace Nz
 
 	LuaState& LuaState::operator=(LuaState&& state) noexcept
 	{
-		m_instance = state.m_instance;
 		m_lastError = std::move(state.m_lastError);
 		m_state = state.m_state;
 
@@ -792,12 +799,14 @@ namespace Nz
 
 	bool LuaState::Run(int argCount, int resultCount)
 	{
-		if (m_instance->m_level++ == 0)
-			m_instance->m_clock.Restart();
+		LuaInstance& instance = GetInstance(m_state);
+
+		if (instance.m_level++ == 0)
+			instance.m_clock.Restart();
 
 		int status = lua_pcall(m_state, argCount, resultCount, 0);
 
-		m_instance->m_level--;
+		instance.m_level--;
 
 		if (status != 0)
 		{
@@ -815,12 +824,12 @@ namespace Nz
 		return lua_upvalueindex(upValue);
 	}
 
-	LuaState LuaState::GetState(lua_State* internalState)
+	LuaInstance& LuaState::GetInstance(lua_State* internalState)
 	{
 		LuaInstance* instance;
 		lua_getallocf(internalState, reinterpret_cast<void**>(&instance));
 
-		return LuaState(instance, internalState);
+		return *instance;
 	}
 
 	int LuaState::ProxyFunc(lua_State* internalState)