Phase 1:  There are no bugs because strong typing, no side effects, functional nature.<p>Phase 2:  OK, but those bugs are my own programmer errors.<p>Phase 3:  I admit it, I have no idea what I&#x27;m doing.<p>Phase 4:  OK, I can&#x27;t even figure out what the Haskell I did two years ago was even trying to do.  I was smarter then.