ResourcesWithResourceT

ResourcesWithResourceT.hs

import Control.Monad.Trans.Resource
import Control.Monad.IO.Class
import System.IO

main :: IO ()
main = runResourceT $ do
  (_, a) <- allocate (openFile "a.txt" ReadMode) hClose
  (_, b) <- allocate (openFile "b.txt" ReadMode) hClose
  aContents <- liftIO $ hGetContents a
  bContents <- liftIO $ hGetContents b
  liftIO . putStrLn $ "contents of a: " <> show aContents
  liftIO . putStrLn $ "contents of b: " <> show bContents