Depends on the language. I am competent in half a dozen languages, and write a lot of functional code. I have written a few projects in Haskell, but I freely a

Depends on the language. I am competent in half a dozen languages, and write a lot of functional code. I have written a few projects in Haskell, but I freely admit theat when I read any of Simon Peyton-Jones papers (eg the one on build systems referenced on HN recently) I am in awe of the way he can map concepts into Haskell code.