bank-kata-haskell-print-1.hs

-- our bank functions
deposit :: Int -> State [Transaction] ()
deposit amount = modify (\transactions -> transactions ++ [Deposit amount])

withdraw :: Int -> State [Transaction] ()
withdraw amount = modify (\transactions -> transactions ++ [Withdrawal amount])

getStatement :: State [Transaction] String
getStatement = gets generateStatement -- the details of generateStatement are out of scope of this post

-- and here's the usage
main = do
  let statement = evalState useMyBank []
  print statement

useMyBank :: State [Transaction] String
useMyBank = do
  deposit 200
  withdraw 100
  getStatement