Function posrelat

depends/lua/src/lstrlib.c:63–67

translate a relative string position: negative means back from end */

/* translate a relative string position: negative means back from end */
static lua_Integer posrelat (lua_Integer pos, size_t len) {
  if (pos >= 0) return pos;
  else if (0u - (size_t)pos > len) return 0;
  else return (lua_Integer)len + pos + 1;
}


static int str_sub (lua_State *L) {