RE: Replace LUA table

[杨俊 <snwcwt@...>]

In your code, you don't replace the table 'a' yet, because you only create a table in the stack that is in the function's stack and is discarded when the function return. Here, the table 'a' is a global var, and you can use lua_setglobal macro to replace the global var 'a' simply. eg:
 
void array2table( lua_State *L, lua_Object lobj )
{
    if (lua_istable (L, lobj))
    {
        printf ("element is table");
 
        int arr[4] = { 5,100,-20,0 };
        lua_newtable(L); // table
 
        for (int i=0; i<4; i++) 
        {
            lua_pushinteger(L, i+1); // table,key
            lua_pushinteger(L, arr[i]); // table,key,value
            lua_settable(L,-3); // table
        }
        //////////////// insert the following line
        lua_setgloabl( L, "a" );
    }
}

of course, the solution isn't perfect, the table 'a' must be a global and the "a" string is limited.
 
the better solution is clear the table, then push the new value, as mention of the others.



 

---

> Subject: Replace LUA table
> Date: Tue, 28 Aug 2007 19:10:12 +0200
> From: Andreas.Volz@elektrobit.com
> To: lua@bazar2.conectiva.com.br
>
> Hello,
>
> I try to replace a LUA table in C++. I do this in LUA:
>
> tc=TestClass:new ()
> a={10,11,12,13,14,15,16,17,18,19,20,21}
> tc:testX (a)
> print (a[1])
> print (a[2])
> print (a[3])
>
> Printed from LUA:
> 10
> 11
> 12
>
> What does testX()?
>
> printf ("dump1:\n");
> stackDump (L);
>
> array2table( L, lobj );
> lua_remove(L, 2);
>
> printf ("dump2:\n");
> stackDump (L);
>
> ... and...
>
> void array2table( lua_State *L, lua_Object lobj )
> {
> if (lua_istable (L, lobj))
> {
> printf ("element is table");
>
> int arr[4] = { 5,100,-20,0 };
> lua_newtable(L); // table
>
> for (int i=0; i<4; i++)
> {
> lua_pushinteger(L, i+1); // table,key
> lua_pushinteger(L, arr[i]); // table,key,value
> lua_settable(L,-3); // table
> }
> }
> }
>
> This in printed in C++:
>
> 31018474 PID:1fe001a TID:53001e dump1:
> 31018474 PID:1fe001a TID:53001e stack dump start
> 31018474 PID:1fe001a TID:53001e userdata
> 31018475 PID:1fe001a TID:53001e
> 31018475 PID:1fe001a TID:53001e table
> 31018476 PID:1fe001a TID:53001e table dump start
> 31018476 PID:1fe001a TID:53001e 10
> 31018477 PID:1fe001a TID:53001e 11
> 31018477 PID:1fe001a TID:53001e 12
> 31018478 PID:1fe001a TID:53001e 13
> 31018479 PID:1fe001a TID:53001e 14
> 31018479 PID:1fe001a TID:53001e 15
> 31018480 PID:1fe001a TID:53001e 16
> 31018480 PID:1fe001a TID:53001e 17
> 31018481 PID:1fe001a TID:53001e 18
> 31018481 PID:1fe001a TID:53001e 19
> 31018482 PID:1fe001a TID:53001e 20
> 31018485 PID:1fe001a TID:53001e 21
> 31018485 PID:1fe001a TID:53001e table dump end
> 31018486 PID:1fe001a TID:53001e
> 31018487 PID:1fe001a TID:53001e
> 31018488 PID:1fe001a TID:53001e stack dump end
> 31018489 PID:1fe001a TID:53001e element is table
>
> 31018490 PID:1fe001a TID:53001e dump2:
> 31018491 PID:1fe001a TID:53001e stack dump start
> 31018492 PID:1fe001a TID:53001e userdata
> 31018492 PID:1fe001a TID:53001e
> 31018493 PID:1fe001a TID:53001e table
> 31018493 PID:1fe001a TID:53001e table dump start
> 31018495 PID:1fe001a TID:53001e 5
> 31018495 PID:1fe001a TID:53001e 100
> 31018496 PID:1fe001a TID:53001e -20
> 31018496 PID:1fe001a TID:53001e 0
> 31018497 PID:1fe001a TID:53001e table dump end
> 31018497 PID:1fe001a TID:53001e
> 31018498 PID:1fe001a TID:53001e
> 31018498 PID:1fe001a TID:53001e stack dump end
>
> As you could see in 'dump2' I replaced the input table with my own table. Looks good so far. But why does LUA then print "10 11 12"? I would expect "5 100 -20". How could I access the table I replace in C++?
>
> If I don't "lua_remove(L, 2);" then the new table is after the input table. But is there any way to access this new table in LUA?
>
> regards
> Andreas
>
> --
> Dipl.-Inf. (FH) Andreas Volz, ES1
> Elektrobit
> Phone: +49 (9131) 7701 167, mailto:Andreas.Volz@elektrobit.com
> Fax: +49 (9131) 7701 333, http://www.elektrobit.com
>
> Elektrobit Automotive GmbH, Am Wolfsmantel 46, 91058 Erlangen, Germany
> Managing Director Otto Fößel
> Register Court Fürth HRB 4886
>
>
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