Initial commit

posix/System/File/Platform.hs

@@ -1,5 +1,10 @@
+{-# LANGUAGE LambdaCase #-}
+
 module System.File.Platform where
 
+import GHC.IO
+import GHC.IO.Exception
+import Control.Exception (try)
 import System.IO (IOMode(..), Handle)
 import System.Posix.IO.PosixString
     ( defaultFileFlags,
@@ -30,3 +35,21 @@ openExistingFile fp iomode = fdToHandle =<< case iomode of
  where
   open = openFd fp
   df = defaultFileFlags { noctty = True, nonBlock = True, creat = Nothing }
+
+withFile :: FilePath -> IOMode -> (Handle -> IO r) -> IO r
+withFile fp im act =
+  -- Only annotate when setup or teardown of withFile' raised the exception
+  catchException
+    (withFile' fp im undefined True (try . act))
+    (\e -> ioError (addFilePathToIOError "withFile" fp e))
+    >>= \case
+      Left e -> ioError e
+      Right x -> pure x
+
+addFilePathToIOError :: String -> FilePath -> IOException -> IOException
+addFilePathToIOError fun fp ioe
+  = ioe{ ioe_location = fun, ioe_filename = Just fp }
+
+withFile' :: String -> IOMode -> Bool -> Bool -> (Handle -> IO r) -> IO r
+withFile' = undefined
+