-{-# OPTIONS_GHC -fno-implicit-prelude #-}
+{-# LANGUAGE CPP, NoImplicitPrelude #-}
-----------------------------------------------------------------------------
-- |
module System.IO.Error (
-- * I\/O errors
- IOError, -- = IOException
+ IOError, -- = IOException
- userError, -- :: String -> IOError
+ userError, -- :: String -> IOError
-#ifndef __NHC__
- mkIOError, -- :: IOErrorType -> String -> Maybe Handle
- -- -> Maybe FilePath -> IOError
+ mkIOError, -- :: IOErrorType -> String -> Maybe Handle
+ -- -> Maybe FilePath -> IOError
- annotateIOError, -- :: IOError -> String -> Maybe Handle
- -- -> Maybe FilePath -> IOError
-#endif
+ annotateIOError, -- :: IOError -> String -> Maybe Handle
+ -- -> Maybe FilePath -> IOError
-- ** Classifying I\/O errors
- isAlreadyExistsError, -- :: IOError -> Bool
+ isAlreadyExistsError, -- :: IOError -> Bool
isDoesNotExistError,
isAlreadyInUseError,
isFullError,
isUserError,
-- ** Attributes of I\/O errors
-#ifndef __NHC__
- ioeGetErrorType, -- :: IOError -> IOErrorType
-#endif
- ioeGetErrorString, -- :: IOError -> String
- ioeGetHandle, -- :: IOError -> Maybe Handle
- ioeGetFileName, -- :: IOError -> Maybe FilePath
-
-#ifndef __NHC__
- ioeSetErrorType, -- :: IOError -> IOErrorType -> IOError
- ioeSetErrorString, -- :: IOError -> String -> IOError
- ioeSetHandle, -- :: IOError -> Handle -> IOError
- ioeSetFileName, -- :: IOError -> FilePath -> IOError
-#endif
+ ioeGetErrorType, -- :: IOError -> IOErrorType
+ ioeGetLocation, -- :: IOError -> String
+ ioeGetErrorString, -- :: IOError -> String
+ ioeGetHandle, -- :: IOError -> Maybe Handle
+ ioeGetFileName, -- :: IOError -> Maybe FilePath
+
+ ioeSetErrorType, -- :: IOError -> IOErrorType -> IOError
+ ioeSetErrorString, -- :: IOError -> String -> IOError
+ ioeSetLocation, -- :: IOError -> String -> IOError
+ ioeSetHandle, -- :: IOError -> Handle -> IOError
+ ioeSetFileName, -- :: IOError -> FilePath -> IOError
-- * Types of I\/O error
- IOErrorType, -- abstract
+ IOErrorType, -- abstract
- alreadyExistsErrorType, -- :: IOErrorType
+ alreadyExistsErrorType, -- :: IOErrorType
doesNotExistErrorType,
alreadyInUseErrorType,
fullErrorType,
userErrorType,
-- ** 'IOErrorType' predicates
- isAlreadyExistsErrorType, -- :: IOErrorType -> Bool
+ isAlreadyExistsErrorType, -- :: IOErrorType -> Bool
isDoesNotExistErrorType,
isAlreadyInUseErrorType,
isFullErrorType,
-- * Throwing and catching I\/O errors
- ioError, -- :: IOError -> IO a
+ ioError, -- :: IOError -> IO a
- catch, -- :: IO a -> (IOError -> IO a) -> IO a
- try, -- :: IO a -> IO (Either IOError a)
+ catchIOError, -- :: IO a -> (IOError -> IO a) -> IO a
+ catch, -- :: IO a -> (IOError -> IO a) -> IO a
+ tryIOError, -- :: IO a -> IO (Either IOError a)
+ try, -- :: IO a -> IO (Either IOError a)
-#ifndef __NHC__
- modifyIOError, -- :: (IOError -> IOError) -> IO a -> IO a
-#endif
+ modifyIOError, -- :: (IOError -> IOError) -> IO a -> IO a
) where
+#ifndef __HUGS__
+import qualified Control.Exception.Base as New (catch)
+#endif
+
+#ifndef __HUGS__
import Data.Either
+#endif
import Data.Maybe
#ifdef __GLASGOW_HASKELL__
import GHC.Base
-import GHC.IOBase
-import GHC.Exception
+import GHC.IO
+import GHC.IO.Exception
+import GHC.IO.Handle.Types
import Text.Show
#endif
#ifdef __HUGS__
-import Hugs.Prelude(Handle, IOException(..), IOErrorType(..))
+import Hugs.Prelude(Handle, IOException(..), IOErrorType(..), IO)
#endif
#ifdef __NHC__
import IO
( IOError ()
+ , Handle ()
, try
, ioError
, userError
- , isAlreadyExistsError -- :: IOError -> Bool
+ , isAlreadyExistsError -- :: IOError -> Bool
, isDoesNotExistError
, isAlreadyInUseError
, isFullError
, ioeGetHandle -- :: IOError -> Maybe Handle
, ioeGetFileName -- :: IOError -> Maybe FilePath
)
---import Data.Maybe (fromJust)
---import Control.Monad (MonadPlus(mplus))
+import qualified NHC.Internal as NHC (IOError(..))
+import qualified NHC.DErrNo as NHC (ErrNo(..))
+import Data.Maybe (fromJust)
+import Control.Monad (MonadPlus(mplus))
#endif
--- | The construct 'try' @comp@ exposes IO errors which occur within a
+-- | The construct 'tryIOError' @comp@ exposes IO errors which occur within a
-- computation, and which are not fully handled.
--
-- Non-I\/O exceptions are not caught by this variant; to catch all
-- exceptions, use 'Control.Exception.try' from "Control.Exception".
+tryIOError :: IO a -> IO (Either IOError a)
+tryIOError f = catch (do r <- f
+ return (Right r))
+ (return . Left)
#ifndef __NHC__
+{-# DEPRECATED try "Please use the new exceptions variant, Control.Exception.try" #-}
+-- | The 'try' function is deprecated. Please use the new exceptions
+-- variant, 'Control.Exception.try' from "Control.Exception", instead.
try :: IO a -> IO (Either IOError a)
try f = catch (do r <- f
return (Right r))
mkIOError :: IOErrorType -> String -> Maybe Handle -> Maybe FilePath -> IOError
mkIOError t location maybe_hdl maybe_filename =
IOError{ ioe_type = t,
- ioe_location = location,
- ioe_description = "",
- ioe_handle = maybe_hdl,
- ioe_filename = maybe_filename
- }
+ ioe_location = location,
+ ioe_description = "",
+#if defined(__GLASGOW_HASKELL__)
+ ioe_errno = Nothing,
+#endif
+ ioe_handle = maybe_hdl,
+ ioe_filename = maybe_filename
+ }
+#endif /* __GLASGOW_HASKELL__ || __HUGS__ */
#ifdef __NHC__
mkIOError EOF location maybe_hdl maybe_filename =
- EOFError location (fromJust maybe_hdl)
+ NHC.EOFError location (fromJust maybe_hdl)
mkIOError UserError location maybe_hdl maybe_filename =
- UserError location ""
+ NHC.UserError location ""
mkIOError t location maybe_hdl maybe_filename =
- NHC.FFI.mkIOError location maybe_filename maybe_handle (ioeTypeToInt t)
+ NHC.IOError location maybe_filename maybe_hdl (ioeTypeToErrNo t)
where
- ioeTypeToInt AlreadyExists = fromEnum EEXIST
- ioeTypeToInt NoSuchThing = fromEnum ENOENT
- ioeTypeToInt ResourceBusy = fromEnum EBUSY
- ioeTypeToInt ResourceExhausted = fromEnum ENOSPC
- ioeTypeToInt IllegalOperation = fromEnum EPERM
- ioeTypeToInt PermissionDenied = fromEnum EACCES
-#endif
-#endif /* __GLASGOW_HASKELL__ || __HUGS__ */
+ ioeTypeToErrNo AlreadyExists = NHC.EEXIST
+ ioeTypeToErrNo NoSuchThing = NHC.ENOENT
+ ioeTypeToErrNo ResourceBusy = NHC.EBUSY
+ ioeTypeToErrNo ResourceExhausted = NHC.ENOSPC
+ ioeTypeToErrNo IllegalOperation = NHC.EPERM
+ ioeTypeToErrNo PermissionDenied = NHC.EACCES
+#endif /* __NHC__ */
#ifndef __NHC__
-- -----------------------------------------------------------------------------
#ifdef __NHC__
data IOErrorType = AlreadyExists | NoSuchThing | ResourceBusy
- | ResourceExhausted | EOF | IllegalOperation
- | PermissionDenied | UserError
+ | ResourceExhausted | EOF | IllegalOperation
+ | PermissionDenied | UserError
#endif
-- | I\/O error where the operation failed because one of its arguments
permissionErrorType = PermissionDenied
-- | I\/O error that is programmer-defined.
-userErrorType :: IOErrorType
-userErrorType = UserError
+userErrorType :: IOErrorType
+userErrorType = UserError
-- -----------------------------------------------------------------------------
-- IOErrorType predicates
-- Miscellaneous
#if defined(__GLASGOW_HASKELL__) || defined(__HUGS__)
-ioeGetErrorType :: IOError -> IOErrorType
+ioeGetErrorType :: IOError -> IOErrorType
ioeGetErrorString :: IOError -> String
+ioeGetLocation :: IOError -> String
ioeGetHandle :: IOError -> Maybe Handle
ioeGetFileName :: IOError -> Maybe FilePath
| isUserErrorType (ioe_type ioe) = ioe_description ioe
| otherwise = show (ioe_type ioe)
+ioeGetLocation ioe = ioe_location ioe
+
ioeGetHandle ioe = ioe_handle ioe
ioeGetFileName ioe = ioe_filename ioe
-ioeSetErrorType :: IOError -> IOErrorType -> IOError
-ioeSetErrorString :: IOError -> String -> IOError
-ioeSetHandle :: IOError -> Handle -> IOError
-ioeSetFileName :: IOError -> FilePath -> IOError
+ioeSetErrorType :: IOError -> IOErrorType -> IOError
+ioeSetErrorString :: IOError -> String -> IOError
+ioeSetLocation :: IOError -> String -> IOError
+ioeSetHandle :: IOError -> Handle -> IOError
+ioeSetFileName :: IOError -> FilePath -> IOError
ioeSetErrorType ioe errtype = ioe{ ioe_type = errtype }
ioeSetErrorString ioe str = ioe{ ioe_description = str }
+ioeSetLocation ioe str = ioe{ ioe_location = str }
ioeSetHandle ioe hdl = ioe{ ioe_handle = Just hdl }
ioeSetFileName ioe filename = ioe{ ioe_filename = Just filename }
+#elif defined(__NHC__)
+ioeGetErrorType :: IOError -> IOErrorType
+ioeGetLocation :: IOError -> String
+
+ioeGetErrorType e | isAlreadyExistsError e = AlreadyExists
+ | isDoesNotExistError e = NoSuchThing
+ | isAlreadyInUseError e = ResourceBusy
+ | isFullError e = ResourceExhausted
+ | isEOFError e = EOF
+ | isIllegalOperation e = IllegalOperation
+ | isPermissionError e = PermissionDenied
+ | isUserError e = UserError
+
+ioeGetLocation (NHC.IOError _ _ _ _) = "unknown location"
+ioeGetLocation (NHC.EOFError _ _ ) = "unknown location"
+ioeGetLocation (NHC.PatternError loc) = loc
+ioeGetLocation (NHC.UserError loc _) = loc
+
+ioeSetErrorType :: IOError -> IOErrorType -> IOError
+ioeSetErrorString :: IOError -> String -> IOError
+ioeSetLocation :: IOError -> String -> IOError
+ioeSetHandle :: IOError -> Handle -> IOError
+ioeSetFileName :: IOError -> FilePath -> IOError
+
+ioeSetErrorType e _ = e
+ioeSetErrorString (NHC.IOError _ f h e) s = NHC.IOError s f h e
+ioeSetErrorString (NHC.EOFError _ f) s = NHC.EOFError s f
+ioeSetErrorString e@(NHC.PatternError _) _ = e
+ioeSetErrorString (NHC.UserError l _) s = NHC.UserError l s
+ioeSetLocation e@(NHC.IOError _ _ _ _) _ = e
+ioeSetLocation e@(NHC.EOFError _ _) _ = e
+ioeSetLocation (NHC.PatternError _) l = NHC.PatternError l
+ioeSetLocation (NHC.UserError _ m) l = NHC.UserError l m
+ioeSetHandle (NHC.IOError o f _ e) h = NHC.IOError o f (Just h) e
+ioeSetHandle (NHC.EOFError o _) h = NHC.EOFError o h
+ioeSetHandle e@(NHC.PatternError _) _ = e
+ioeSetHandle e@(NHC.UserError _ _) _ = e
+ioeSetFileName (NHC.IOError o _ h e) f = NHC.IOError o (Just f) h e
+ioeSetFileName e _ = e
+#endif
+
-- | Catch any 'IOError' that occurs in the computation and throw a
-- modified version.
modifyIOError :: (IOError -> IOError) -> IO a -> IO a
-> Maybe Handle
-> Maybe FilePath
-> IOError
-annotateIOError (IOError ohdl errTy _ str opath) loc hdl path =
- IOError (hdl `mplus` ohdl) errTy loc str (path `mplus` opath)
+
+#if defined(__GLASGOW_HASKELL__) || defined(__HUGS__)
+annotateIOError ioe loc hdl path =
+ ioe{ ioe_handle = hdl `mplus` ioe_handle ioe,
+ ioe_location = loc, ioe_filename = path `mplus` ioe_filename ioe }
where
+ mplus :: Maybe a -> Maybe a -> Maybe a
Nothing `mplus` ys = ys
xs `mplus` _ = xs
#endif /* __GLASGOW_HASKELL__ || __HUGS__ */
-#if 0 /*__NHC__*/
-annotateIOError (IOError msg file hdl code) msg' file' hdl' =
- IOError (msg++'\n':msg') (file`mplus`file') (hdl`mplus`hdl') code
-annotateIOError (EOFError msg hdl) msg' file' hdl' =
- EOFError (msg++'\n':msg') (hdl`mplus`hdl')
-annotateIOError (UserError loc msg) msg' file' hdl' =
- UserError loc (msg++'\n':msg')
-annotateIOError (PatternError loc) msg' file' hdl' =
- PatternError (loc++'\n':msg')
+#if defined(__NHC__)
+annotateIOError (NHC.IOError msg file hdl code) msg' hdl' file' =
+ NHC.IOError (msg++'\n':msg') (file`mplus`file') (hdl`mplus`hdl') code
+annotateIOError (NHC.EOFError msg hdl) msg' _ _ =
+ NHC.EOFError (msg++'\n':msg') hdl
+annotateIOError (NHC.UserError loc msg) msg' _ _ =
+ NHC.UserError loc (msg++'\n':msg')
+annotateIOError (NHC.PatternError loc) msg' _ _ =
+ NHC.PatternError (loc++'\n':msg')
#endif
+
+#ifndef __HUGS__
+-- | The 'catchIOError' function establishes a handler that receives any
+-- 'IOError' raised in the action protected by 'catchIOError'.
+-- An 'IOError' is caught by
+-- the most recent handler established by one of the exception handling
+-- functions. These handlers are
+-- not selective: all 'IOError's are caught. Exception propagation
+-- must be explicitly provided in a handler by re-raising any unwanted
+-- exceptions. For example, in
+--
+-- > f = catchIOError g (\e -> if IO.isEOFError e then return [] else ioError e)
+--
+-- the function @f@ returns @[]@ when an end-of-file exception
+-- (cf. 'System.IO.Error.isEOFError') occurs in @g@; otherwise, the
+-- exception is propagated to the next outer handler.
+--
+-- When an exception propagates outside the main program, the Haskell
+-- system prints the associated 'IOError' value and exits the program.
+--
+-- Non-I\/O exceptions are not caught by this variant; to catch all
+-- exceptions, use 'Control.Exception.catch' from "Control.Exception".
+catchIOError :: IO a -> (IOError -> IO a) -> IO a
+catchIOError = New.catch
+
+{-# DEPRECATED catch "Please use the new exceptions variant, Control.Exception.catch" #-}
+-- | The 'catch' function is deprecated. Please use the new exceptions
+-- variant, 'Control.Exception.catch' from "Control.Exception", instead.
+catch :: IO a -> (IOError -> IO a) -> IO a
+catch = New.catch
+#endif /* !__HUGS__ */
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