[zoomerang]

I went into FP from the perspective of a Python/Javascript/Groovy zealot, considered FP to be a silly academic thing with no real world applications.

Took me about a week to be productive in Scala in a functional style. Haskell is a little more complex, but I found that throwing myself in the deep end, while frustrating, was not overly difficult.

The cost of switching to FP only seems high because people don't want to even bother trying. Once you've gotten over the initial bump, FP is (in my opinion) substantially easier to wrote code in.