From: Xavier Noria Date: 2013-01-09T17:40:21+09:00 Subject: Re: Re-implementing Autoload You surely know that, but let me comment that this autoload behaves in a different way. You sure know the original autoload is transparently hooked into each step of constant resolution and does not go through const_missing. Also, since const_missing does not know the nesting, and does not know the resolution algorithm that is being used, you just cannot emulate it. Active Support autoloading suffers from the same constraints and that is why it does not claim to emulate constant resolution (it cannot), rather AS autoloading gives you a series of conventions that if you follow then it works. You have to program to a contract.