There are memoization libraries for PHP but really it's just another cache implementation. Put it in RAM, put it on disk, put it in memcached or redis, I don't

There are memoization libraries for PHP but really it's just another cache implementation. Put it in RAM, put it on disk, put it in memcached or redis, I don't really see too much a difference between $cache->set($key, $value) in PHP vs cache[key] = value in node for instance.