RE: calling table:function from c/c++

["Nick Trout" <ntrout@...>]

> -- test.lua
> test = {}
> function test:fn (num1, num2)
>   return num1 + num2
> end
> 
> 
> now, I wanted to call this function from c/c++,
> 
> 
> lua_State *L = lua_open(0); 
> lua_baselibopen(L); 
> lua_dofile (L, "test.lua");  
> lua_getglobal(L, "test:fn");
> lua_pushnumber(L, 100);
> lua_pushnumber(L, 200);
> lua_call(L, 2, 1);
> printf("result : %d\n", (int)lua_tonumber(L, -1)); 
> lua_close(L); 
> 
> 
> which doesn't work. The program complains about calling nil function. 
> My rough guess is that the function "test:fn" belongs to the 
> table "test", and not globally known. But, I don't know how to 
> correct it.

Lua script:

test:fn(100, 200)

lua2c generates the following: 

static int MAIN(lua_State *L)
{
 lua_getglobal(L,"test");
 lua_pushstring(L,"fn");
 lua_gettable(L,-2);
 lua_insert(L,-2);
 lua_pushnumber(L,100);
 lua_pushnumber(L,200);
 lua_call(L,3,0);
 return 0;
}

so you can use:

 lua_getglobal(L,"test");
 lua_pushstring(L,"fn");
 lua_gettable(L,-2);
 lua_insert(L,-2);
 lua_pushnumber(L,100);
 lua_pushnumber(L,200);
 lua_call(L,3,0);

from http://doris.sourceforge.net/lua/weblua.php

Just type code into the text area and hit lua2c.


Nick