/// <summary>
        /// Get the amount of memory used, according to the Lua memory manager
        /// </summary>
        /// <returns>Number of bytes used</returns>
        public static uint GetUsedMem(Lua.lua_State L)
        {
            // Perform a full GC pass first
            Lua.luaC_fullgc(L);

            return L.l_G.totalbytes;
        }

 static Lua.Proto combine(Lua.lua_State L, int n)
 {
     if (n==1)
       return toproto(L,-1);
      else
      {
       int i,pc;
       Lua.Proto f=Lua.luaF_newproto(L);
       Lua.setptvalue2s(L,L.top,f); Lua.incr_top(L);
       f.source=Lua.luaS_newliteral(L,"=(" + PROGNAME + ")");
       f.maxstacksize=1;
       pc=2*n+1;
       f.code = (Instruction[])Lua.luaM_newvector<Instruction>(L, pc);
       f.sizecode=pc;
       f.p = Lua.luaM_newvector<Lua.Proto>(L, n);
       f.sizep=n;
       pc=0;
       for (i=0; i<n; i++)
       {
        f.p[i]=toproto(L,i-n-1);
        f.code[pc++]=(uint)Lua.CREATE_ABx(Lua.OpCode.OP_CLOSURE,0,i);
        f.code[pc++]=(uint)Lua.CREATE_ABC(Lua.OpCode.OP_CALL,0,1,1);
       }
       f.code[pc++]=(uint)Lua.CREATE_ABC(Lua.OpCode.OP_RETURN,0,1,0);
       return f;
      }
 }

 public override object To(Lua.lua_State State, int Index)
 {
     if (Lua.lua_isnumber(State, Index) > 0)
         return (int)Lua.lua_tonumber(State, Index);
     else
         throw new Exception(String.Format("Expected integer (Got {0}).", Lua.lua_typename(State, Index).ToString()));
 }

 public void AssertLuaResult(Lua.lua_State L, int result)
 {
     if (result != 0)
     {
         Utils.DumpStack(L);
         Assert.Fail(GetLuaError(L));
     }
 }

        public string GetLuaError(Lua.lua_State L)
        {
            if (Lua.lua_gettop(L) == 0)
                return "(no error message)";

            var s = Lua.lua_tostring(L, -1);
            if (s == null)
                return "(null error message)";

            return s.ToString();
        }

		static int report(Lua.lua_State L, int status)
		{
			if ((status!=0) && !Lua.lua_isnil(L, -1))
			{
				Lua.CharPtr msg = Lua.lua_tostring(L, -1);
				if (msg == null) msg = "(error object is not a string)";
				l_message(progname, msg);
				Lua.lua_pop(L, 1);
			}
			return status;
		}

 public static void DumpStack(Lua.lua_State L)
 {
     for (int i = -Lua.lua_gettop(L); i < 0; ++i)
     {
         string s = "?";
         int t = Lua.lua_type(L, i);
         switch (t)
         {
             case Lua.LUA_TSTRING:
                 s = Lua.lua_tostring(L, i).ToString();
                 break;
             case Lua.LUA_TBOOLEAN:
                 s = Lua.lua_toboolean(L, i) != 0 ? "true" : "false";
                 break;
             case Lua.LUA_TNUMBER:
                 s = Lua.lua_tonumber(L, i).ToString();
                 break;
         }
         Debug.WriteLine(string.Format("{0}: {1} {2}", i, Lua.lua_typename(L, t), s));
     }
 }

			public Node(Lua.LuaTypeValue i_val, TKey i_key)
			{
				this.values = new Node[] { this };
				this.index = 0;
				this.i_val = i_val;
				this.i_key = i_key;
			}

		internal static bool IsCollectable(Lua.LuaTypeValue o) { return (TType(o) >= LUA_TSTRING); }

		//#define setsvalue2n	setsvalue
		internal static void SetSValue2N(LuaState L, Lua.LuaTypeValue obj, TString x) { SetSValue(L, obj, x); }

		//#define setptvalue2s	setptvalue
		internal static void SetPTValue2S(LuaState L, Lua.LuaTypeValue obj, Proto x) { SetPTValue(L, obj, x); }

		internal static void SetObj(LuaState L, Lua.LuaTypeValue obj1, Lua.LuaTypeValue obj2) {
			obj1.value.Copy(obj2.value);
			obj1.tt = obj2.tt;
			CheckLiveness(G(L), obj1);
		}

		internal static void SetHValue(LuaState L, Lua.LuaTypeValue obj, Table x) {
			obj.value.gc = x;
			obj.tt = LUA_TTABLE;
			CheckLiveness(G(L), obj);
		}

		internal static LuaState THValue(Lua.LuaTypeValue o) { return (LuaState)CheckExp(TTIsThread(o), o.value.gc.th); }

		internal static int BValue(Lua.LuaTypeValue o) { return o.value.b; }

		internal static void SetTTHValue(LuaState L, Lua.LuaTypeValue obj, GCObject x) {
			obj.value.gc = x;
			obj.tt = LUA_TTHREAD;
			CheckLiveness(G(L), obj);
		}

		internal static void SetCLValue(LuaState L, Lua.LuaTypeValue obj, Closure x) {
			obj.value.gc = x;
			obj.tt = LUA_TFUNCTION;
			CheckLiveness(G(L), obj);
		}

		public static int LIsFalse(Lua.LuaTypeValue o) { return ((TTIsNil(o) || (TTIsBoolean(o) && BValue(o) == 0))) ? 1 : 0; }

		internal static void SetPTValue(LuaState L, Lua.LuaTypeValue obj, Proto x) {
			obj.value.gc = x;
			obj.tt = LUATPROTO;
			CheckLiveness(G(L), obj);
		}

		internal static void CheckConsistency(Lua.LuaTypeValue obj)
		{
			LuaAssert(!IsCollectable(obj) || (TType(obj) == (obj).value.gc.gch.tt));
		}