Lua is not written to support C++ in any
way, so exceptions are never needed to catch the results of lua functions.
I don't use luaL_check*, so I'm not 100%
on those functions, but this should fix the loop. Also, I didn't compile this
code, I just wrote it off the top of my head, so there might be an error!
int LCamera::setEffects(lua_State *L)
{
int arguments = lua_gettop(L);
lua_Number
effect;
for (int
i = 1; i <= arguments; i++)
{
effect = luaL_checkint(L,i);
cout << "effect: "
<< effect << cout;
}
cout << "number of
arguments: " << arguments << endl;
return 0;
}
To return multiple values, push them onto
the stack and then return the number of return values that are on the stack.
Remember that the parameters are also on the stack so you will need to pop them
off before you push your return values. You are guaranteed to have some
standard amount of free space on the stack. I think the default is 16 free
places on the stack when your C function is called. If you push more than 16,
then you need to check if there is enough free space before you do that.
Jonathan Branam
Systems Analyst
Application Development
Ontario Systems
Tel 765.751.7384
From: lua-bounces@bazar2.conectiva.com.br
[mailto:lua-bounces@bazar2.conectiva.com.br] On
Behalf Of Zé Pedro
Sent: Tuesday, June 13, 2006 5:54
AM
To: lua@bazar2.conectiva.com.br
Subject: Passing arrays(tables)
between C++ and Lua and vice versa
Hi,
I'm creating some functions in c++ and making them available to lua. Some of
this functions required to return and/or receive arrays (in lua arrays are
implemented with tables right?).
For example, I have a function called setEffects that can receive an
indetermined number of ints. How can I do this? I have tried the following
code:
int LCamera::setEffects(lua_State *L)
{
int argument = 1;
try
{
lua_Number effect;
while (true)
{
luaL_checktype(L,
argument, LUA_TNUMBER);
effect =
luaL_checkint(L,1);
cout <<
"effect: " << effect << cout;
argument++;
}
} catch (...)
{
//Do nothing. Only checking number of
arguments
cout << "number of arguments:
" << argument << endl;
}
return 0;
}
I did this hoping that when there were no more arguments an exception would be
thrown and catched in the try-catch block, but it isn't the case. An
alternative is to pass as argument an array but how?
The other problem is to return a table. If I have a method that can return
several values how can I do it?
thanks,
Jose Tavares
PS: sorry for the poor english
--
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no matter if I have said it, unless it agrees with your own reason
and your common sense.
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