Hi all, I have used GetOpt in Python and Ocaml so I am reasonably familiar with it, and I have been studying the technique here: http://www.haskell.org/haskellwiki/High-level_option_handling_with_GetOpt Can anyone explain to me what is actually happening here: opts <- foldl (>>=) (return startOptions) actions let Options { optVerbose = verbose , optInput = input , optOutput = output } = opts input >>= output I understand the fold is evaluating everything in the actions list overlaying them onto the startOptions record, then getting these out of IO and into the opts record - but where are "verbose", "input" and "output" coming from? Are they just aliases? Any insight gratefully received :-) Thanks, G