Returning function from Lua

Why don't you try to return multiple values?
Like:
return Commands.Attack, Commands.Defend, Commands.Destroy

Quote:

Original post by streamer Why don't you try to return multiple values? Like: return Commands.Attack, Commands.Defend, Commands.Destroy

I have tried that already but the problem remains. Also changing Commands_[1] to Commands_ and passing only one function (like Commands.Attack) doesn't help. Maybe it is impossible to do this? Or the way the function is passed is wrong.

But what are you try to do? Pass values to LUA or pass values from LUA to c++?

also if this:

Commands.Attack = function (FromProxy, TargetProxy) print ("Attack") end
Commands.Defend = function (FromProxy, TargetProxy) print ("Defend") end
Commands.Construct = function (FromProxy, TargetProxy) print ("Construct") end
Commands.Destroy = function (FromProxy, TartgetProxy) print ("Destroy") end

are function definitions you need

Commands.Attack = function Attack(FromProxy, TargetProxy) print ("Attack") end
Commands.Defend = function Defend(FromProxy, TargetProxy) print ("Defend") end
Commands.Construct = function Construct(FromProxy, TargetProxy) print ("Construct") end
Commands.Destroy = function Destroy(FromProxy, TartgetProxy) print ("Destroy") end

and also they are missing returning values

function Attack(FromProxy, TargetProxy)
print ("Attack")
AttackNMY(1)
return 1
end

Commands.Attack = Attack(1,1)

in c++:
...
int AttackNMY(lua_State *pLuaState )
{
const int s = (int)lua_tonumber(pLuaState,1);

// s is argument of AttackNMY in LUA

return 1;
}

...
lua_register( pLuaState, "AttackNMY", AttackNMY);

The title of the topic is 'Returning function from Lua'. So I'm trying to pass a function from LUA to C++.

Then check my edited post [smile]

a little explanation:

pLuaState = lua_open();
luaopen_base(pLuaState); /* opens the basic library */
luaopen_table(pLuaState); /* opens the table library */
luaopen_io(pLuaState); /* opens the I/O library */
luaopen_string(pLuaState); /* opens the string lib. */
luaopen_math(pLuaState); /* opens the math lib. */
with:
lua_register( pLuaState, "AttackNMY", AttackNMY);

you register a Lua function called AttackNMY and bind it with AttackNMY c++ function ("AttackNMY" LUA, AttackNMY c++).

So when you execute LUA script:

lua_dofile( pLuaState,"myscript.lua");

when LUA finds AttackNMY function in script, LUA calls binded C++ function, in this case function with same name AttacNMY()

int AttackNMY(lua_State *pLuaState )
{
const int s = (int)lua_tonumber(pLuaState,1);

// s is argument of AttackNMY in LUA

return 1;
}

you can get any number of parameters with
const int s = (int)lua_tonumber(pLuaState,1); // first parameter number
const char *g = lua_tostring(pLuaState, 2);// second param string

returng values to LUA are
lua_pushstring(pLuaState, "yeah");
lua_pushboolean(pLuaState, (int)false);
lua_pushnumber( pLuaState, 1 );

you can push back multiple results

int AttackNMY(lua_State *pLuaState )
{
const int s = (int)lua_tonumber(pLuaState,1);

// s is argument of AttackNMY in LUA
lua_pushboolean(pLuaState, (int)true); // attack someone
lua_pushnumber( pLuaState, 1 ); // attack enemy 1
return 1;
}

I hope this clears some thing to you.

That was a very interesting explanation about how to use LUA in C(++). But what I really need is a Luabind implementation.
And the problem isn't solved either because in fact I want that Lua returns a set of Lua functions and save that in a luabind object and later use the functions in that object with my C++ program (see my initial post and the luabind docs).

Nevertheless thanks for your help.

Sorry, but I'm not familiar with luabind. I use plain LUA with c++.
[sad]

If you want to call a lua function from C, use lua_call:
http://www.lua.org/manual/5.1/manual.html#lua_call
Call your SetPropertyCommand with lua_call, and then you ll get your functions table.
I never used luabind to bind lua classes to C++ (even though the main page says that it is possible), but anyway i dont use luabind anymore, cant help you with that. But lua_call is probably what you are looking for.

/kUfa