Reaktor.Plugins.System.hWithLines: use untilM_

2 files changed, 16 insertions, 7 deletions

diff --git a/src/Control/Monad/Extended.hs b/src/Control/Monad/Extended.hs
new file mode 100644
index 0000000..d91b12c
--- /dev/null
+++ b/src/Control/Monad/Extended.hs
@@ -0,0 +1,14 @@
+module Control.Monad.Extended
+    ( module Control.Monad
+    , unlessM_
+    , untilM_
+    ) where
+
+import Control.Monad
+
+
+unlessM_ :: Monad m => m Bool -> m () -> m ()
+unlessM_ p f = p >>= flip unless f
+
+untilM_ :: Monad m => m Bool -> m a -> m ()
+untilM_ p f = unlessM_ p (f >> untilM_ p f)
diff --git a/src/Reaktor/Plugins/System.hs b/src/Reaktor/Plugins/System.hs
index 8ca468c..de96a61 100644
--- a/src/Reaktor/Plugins/System.hs
+++ b/src/Reaktor/Plugins/System.hs
@@ -10,7 +10,7 @@ import Control.Applicative
 import Control.Concurrent (forkIO,threadDelay)
 import Control.Concurrent.Async (race)
 import Control.Exception
-import Control.Monad (forM_)
+import Control.Monad.Extended (forM_,untilM_)
 import qualified Data.HashMap.Lazy as M
 import qualified Data.List as L
 import qualified Data.Text.Extended as T
@@ -217,9 +217,4 @@ signalProcessGroup' sig pgid =
 hWithLines :: Handle -> (Text -> IO ()) -> IO ()
 hWithLines h f = do
     hSetBuffering h LineBuffering
-    go `finally` hClose h
-  where
-    go =
-      hIsEOF h >>= \case
-        True -> return ()
-        False -> T.hGetLine h >>= f >> go
+    untilM_ (hIsEOF h) (T.hGetLine h >>= f) `finally` hClose h