Re: how to construct sturct object in lua

It was thus said that the Great Jim zhang once stated:
> Code to be test:
> struct A
> {
> int a,
> int b
> };
>
> int sum ( struct A * s)
> {
> retunr s->a+s->b;
> }
>
> How could I construct a struct A object in lua scripts, and pass the pointer of this struct into sum() to test it?

Well, here's one way:

------- Lua -----------

sum = require "sum"

x = { a = 1 , b = 2 }

y = sum(x)
print(y)

z = sum { a = 2 , b = 3 }
print(z)

/********* C *******************/

#include <lua.h>
#include <lauxlib.h>

static int sumlua(lua_State *L)
{
struct A;
int x;

lua_getfield(L,1,"a");
lua_getfield(L,1,"b");

A.a = luaL_checkinteger(L,-2);
A.b = luaL_checkinteger(L,-1);
x = sum(&A);
lua_pushinteger(L,x);
return 1;
}

int luaopen_sum(lua_State *L)
{
lua_pushcfunction(L,sumlua);
return 1;
}

Compile the C code into the appropriate shared object for your platform, and
then the Lua code will be able to load the C interface.

-spc