Your comparing "nasty" fp with "well-structured" OO, but let's ignore that for the moment. My experience is the opposite. I run into a lot of nasty legacy OO c

Your comparing "nasty" fp with "well-structured" OO, but let's ignore that for the moment. My experience is the opposite. I run into a lot of nasty legacy OO code (think java not smalltalk) and it's very hard for me to refactor it piecemeal. I've been doing a clojure project at work for the past 6 months and it's surprisingly easy to refactor side effect free code.