Function unpack

third-party/lua-5.2.4/src/ltablib.c:137–151

static int unpack (lua_State *L) {
  int i, e;
  unsigned int n;
  luaL_checktype(L, 1, LUA_TTABLE);
  i = luaL_optint(L, 2, 1);
  e = luaL_opt(L, luaL_checkint, 3, luaL_len(L, 1));
  if (i > e) return 0;  /* empty range */
  n = (unsigned int)e - (unsigned int)i;  /* number of elements minus 1 */
  if (n > (INT_MAX - 10) || !lua_checkstack(L, ++n))
    return luaL_error(L, "too many results to unpack");
  lua_rawgeti(L, 1, i);  /* push arg[i] (avoiding overflow problems) */
  while (i++ < e)  /* push arg[i + 1...e] */
    lua_rawgeti(L, 1, i);
  return n;
}

/* }====================================================== */