Function str_byte

third-party/lua-5.5.0/src/lstrlib.c:166–181

static int str_byte (lua_State *L) {
  size_t l;
  const char *s = luaL_checklstring(L, 1, &l);
  lua_Integer pi = luaL_optinteger(L, 2, 1);
  size_t posi = posrelatI(pi, l);
  size_t pose = getendpos(L, 3, pi, l);
  int n, i;
  if (posi > pose) return 0;  /* empty interval; return no values */
  if (l_unlikely(pose - posi >= (size_t)INT_MAX))  /* arithmetic overflow? */
    return luaL_error(L, "string slice too long");
  n = (int)(pose -  posi) + 1;
  luaL_checkstack(L, n, "string slice too long");
  for (i=0; i<n; i++)
    lua_pushinteger(L, cast_uchar(s[posi + cast_uint(i) - 1]));
  return n;
}


static int str_char (lua_State *L) {