histogram. implement writer in terms of state monad?

histogram.hs

first :: State [String] Int
first = state $ \initialstate -> (0, initialstate)

appender to_emit to_append = (state $ \lateststate -> (to_emit, (show to_append):lateststate))

histogram = do
  firstanswer  <- first
  secondanswer <- appender "HI" firstanswer
  appender 876 secondanswer

main = let foo = runState histogram []
       in putStrLn $ show foo