Function checktab

src/Chain/libraries/glua/ltablib.cpp:45–57

** Check that 'arg' either is a table or can behave like one (that is, ** has a metatable with the required metamethods) */

** has a metatable with the required metamethods)
*/
static void checktab(lua_State *L, int arg, int what) {
    if (lua_type(L, arg) != LUA_TTABLE) {  /* is it not a table? */
        int n = 1;  /* number of elements to pop */
        if (lua_getmetatable(L, arg) &&  /* must have metatable */
            (!(what & TAB_R) || checkfield(L, "__index", ++n)) &&
            (!(what & TAB_W) || checkfield(L, "__newindex", ++n)) &&
            (!(what & TAB_L) || checkfield(L, "__len", ++n))) {
            lua_pop(L, n);  /* pop metatable and tested metamethods */
        }
        else
            luaL_argerror(L, arg, "table expected");  /* force an error */
    }
}


#if defined(LUA_COMPAT_MAXN)