Streaming read

src/Control/Addressbook/Streaming.hs

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+module Control.Addressbook.Streaming where
+
+import qualified Data.Text as T
+
+import Conduit
+import qualified Data.Conduit.Binary as CB
+import qualified Data.Conduit.Combinators as C
+import qualified Data.Conduit.List as CL
+import qualified Data.Conduit.Text as CT
+
+import Data.Email
+import Data.Email.Header
+       (Header)
+
+import System.IO
+       (stdin)
+
+combine :: (MonadResource m, MonadThrow m, MonadIO m) => ConduitM FilePath Header m ()
+combine = await >>= \case
+  Nothing -> pure ()
+  Just path -> (CB.sourceFile path .| parseEmail) >> combine
+
+run :: IO ()
+run = do
+  runResourceT $ runConduit (CB.sourceHandle stdin .| CT.decode CT.utf8 .| CT.lines .| C.map T.unpack .| combine .| C.mapM_ (liftIO . print))