Function addfield

deps/lua/src/ltablib.c:135–141

static void addfield (lua_State *L, luaL_Buffer *b, int i) {
  lua_rawgeti(L, 1, i);
  if (!lua_isstring(L, -1))
    luaL_error(L, "invalid value (%s) at index %d in table for "
                  LUA_QL("concat"), luaL_typename(L, -1), i);
  luaL_addvalue(b);
}


static int tconcat (lua_State *L) {