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src/Show.hs

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+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+
+module Show (
+  Print(..),
+  putText,
+  putLText,
+) where
+
+import Prelude ((.), Char, IO)
+import qualified Prelude
+
+import Control.Monad.IO.Class (MonadIO, liftIO)
+import qualified Data.ByteString.Char8 as BS
+import qualified Data.ByteString.Lazy.Char8 as BL
+
+import qualified Data.Text as T
+import qualified Data.Text.IO as T
+
+import qualified Data.Text.Lazy as TL
+import qualified Data.Text.Lazy.IO as TL
+
+class Print a where
+  putStr :: MonadIO m => a -> m ()
+  putStrLn :: MonadIO m => a -> m ()
+
+instance Print T.Text where
+  putStr = liftIO . T.putStr
+  putStrLn = liftIO . T.putStrLn
+
+instance Print TL.Text where
+  putStr = liftIO . TL.putStr
+  putStrLn = liftIO . TL.putStrLn
+
+instance Print BS.ByteString where
+  putStr = liftIO . BS.putStr
+  putStrLn = liftIO . BS.putStrLn
+
+instance Print BL.ByteString where
+  putStr = liftIO . BL.putStr
+  putStrLn = liftIO . BL.putStrLn
+
+instance Print [Char] where
+  putStr = liftIO . Prelude.putStr
+  putStrLn = liftIO . Prelude.putStrLn
+
+-- For forcing type inference
+putText :: MonadIO m => T.Text -> m ()
+putText = putStrLn
+{-# SPECIALIZE putText :: T.Text -> IO () #-}
+
+putLText :: MonadIO m => TL.Text -> m ()
+putLText = putStrLn
+{-# SPECIALIZE putLText :: TL.Text -> IO () #-}