module PrelHandle where
-import PrelST
-import PrelArr ( ByteArray(..), newVar, readVar, writeVar )
+import PrelBase
+import PrelArr ( newVar, readVar, writeVar, ByteArray )
import PrelRead ( Read )
import PrelList ( span )
import PrelIOBase
-import PrelUnsafe ( unsafePerformIO )
-import PrelTup
-import PrelMaybe
-import PrelBase
-import PrelAddr
-import PrelErr ( error )
-import PrelGHC
+import PrelMaybe ( Maybe(..) )
+import PrelAddr ( Addr, nullAddr )
+import PrelBounded () -- get at Bounded Int instance.
+import PrelNum ( toInteger )
import Ix
#ifndef __PARALLEL_HASKELL__
%*********************************************************
%* *
-\subsection{Types @FilePath@, @Handle@, @Handle__@}
+\subsection{Types @Handle@, @Handle__@}
%* *
%*********************************************************
The @Handle@ and @Handle__@ types are defined in @IOBase@.
\begin{code}
-type FilePath = String
-
{-# INLINE newHandle #-}
{-# INLINE readHandle #-}
{-# INLINE writeHandle #-}
writeHandle (Handle h) hc = stToIO (writeVar h hc)
#endif
-\end{code}
-
-%*********************************************************
-%* *
-\subsection{Functions}
-%* *
-%*********************************************************
-\begin{code}
-#ifndef __PARALLEL_HASKELL__
-filePtr :: Handle__ -> ForeignObj
-#else
-filePtr :: Handle__ -> Addr
-#endif
-filePtr (SemiClosedHandle fp _) = fp
-filePtr (ReadHandle fp _ _) = fp
-filePtr (WriteHandle fp _ _) = fp
-filePtr (AppendHandle fp _ _) = fp
-filePtr (ReadWriteHandle fp _ _) = fp
-
-bufferMode :: Handle__ -> Maybe BufferMode
-bufferMode (ReadHandle _ m _) = m
-bufferMode (WriteHandle _ m _) = m
-bufferMode (AppendHandle _ m _) = m
-bufferMode (ReadWriteHandle _ m _) = m
-
-markHandle :: Handle__ -> Handle__
-markHandle h@(ReadHandle fp m b)
- | b = h
- | otherwise = ReadHandle fp m True
-markHandle h@(WriteHandle fp m b)
- | b = h
- | otherwise = WriteHandle fp m True
-markHandle h@(AppendHandle fp m b)
- | b = h
- | otherwise = AppendHandle fp m True
-markHandle h@(ReadWriteHandle fp m b)
- | b = h
- | otherwise = ReadWriteHandle fp m True
\end{code}
--------------------------------------------
-
%*********************************************************
%* *
\subsection[StdHandles]{Standard handles}
\begin{code}
stdin, stdout, stderr :: Handle
-stdin = unsafePerformIO (do
- rc <- _ccall_ getLock (``stdin''::Addr) 0
+stdout = unsafePerformIO (do
+ rc <- _ccall_ getLock 1 1 -- ConcHask: SAFE, won't block
case rc of
- 0 -> newHandle ClosedHandle
+ 0 -> newHandle (mkClosedHandle__)
1 -> do
-#ifndef __PARALLEL_HASKELL__
- fp <- makeForeignObj (``stdin''::Addr) (``&freeStdFile''::Addr)
- newHandle (ReadHandle fp Nothing False)
+#ifndef __CONCURRENT_HASKELL__
+ fo <- _ccall_ openStdFile 1 1{-flush on close-} 0{-writeable-} -- ConcHask: SAFE, won't block
#else
- newHandle (ReadHandle ``stdin'' Nothing False)
+ fo <- _ccall_ openStdFile 1 (1{-flush on close-} + 128{-don't block on I/O-})
+ 0{-writeable-} -- ConcHask: SAFE, won't block
#endif
- _ -> do ioError <- constructError "stdin"
- newHandle (ErrorHandle ioError)
+
+#ifndef __PARALLEL_HASKELL__
+ fo <- makeForeignObj fo (``&freeStdFileObject''::Addr)
+#endif
+ (bm, bf_size) <- getBMode__ fo
+ mkBuffer__ fo bf_size
+ newHandle (Handle__ fo WriteHandle bm "stdout")
+ _ -> do ioError <- constructError "stdout"
+ newHandle (mkErrorHandle__ ioError)
)
-stdout = unsafePerformIO (do
- rc <- _ccall_ getLock (``stdout''::Addr) 1
+stdin = unsafePerformIO (do
+ rc <- _ccall_ getLock 0 0 -- ConcHask: SAFE, won't block
case rc of
- 0 -> newHandle ClosedHandle
+ 0 -> newHandle (mkClosedHandle__)
1 -> do
-#ifndef __PARALLEL_HASKELL__
- fp <- makeForeignObj (``stdout''::Addr) (``&freeStdFile''::Addr)
- newHandle (WriteHandle fp Nothing False)
+#ifndef __CONCURRENT_HASKELL__
+ fo <- _ccall_ openStdFile 0 0{-don't flush on close -} 1{-readable-} -- ConcHask: SAFE, won't block
#else
- newHandle (WriteHandle ``stdout'' Nothing False)
+ fo <- _ccall_ openStdFile 0 (0{-flush on close-} + 128{-don't block on I/O-})
+ 1{-readable-} -- ConcHask: SAFE, won't block
#endif
- _ -> do ioError <- constructError "stdout"
- newHandle (ErrorHandle ioError)
+
+#ifndef __PARALLEL_HASKELL__
+ fo <- makeForeignObj fo (``&freeStdFileObject''::Addr)
+#endif
+ (bm, bf_size) <- getBMode__ fo
+ mkBuffer__ fo bf_size
+ hdl <- newHandle (Handle__ fo ReadHandle bm "stdin")
+ -- when stdin and stdout are both connected to a terminal, ensure
+ -- that anything buffered on stdout is flushed prior to reading from stdin.
+ --
+ hConnectTerms stdout hdl
+ return hdl
+ _ -> do ioError <- constructError "stdin"
+ newHandle (mkErrorHandle__ ioError)
)
+
stderr = unsafePerformIO (do
- rc <- _ccall_ getLock (``stderr''::Addr) 1
+ rc <- _ccall_ getLock 2 1 -- ConcHask: SAFE, won't block
case rc of
- 0 -> newHandle ClosedHandle
+ 0 -> newHandle (mkClosedHandle__)
1 -> do
-#ifndef __PARALLEL_HASKELL__
- fp <- makeForeignObj (``stderr''::Addr) (``&freeStdFile''::Addr)
- newHandle (WriteHandle fp (Just NoBuffering) False)
+#ifndef __CONCURRENT_HASKELL__
+ fo <- _ccall_ openStdFile 2 1{-flush on close-} 0{-writeable-} -- ConcHask: SAFE, won't block
#else
- newHandle (WriteHandle ``stderr'' (Just NoBuffering) False)
+ fo <- _ccall_ openStdFile 2 (1{-flush on close-} + 128{-don't block on I/O-})
+ 0{-writeable-} -- ConcHask: SAFE, won't block
+#endif
+
+#ifndef __PARALLEL_HASKELL__
+ fo <- makeForeignObj fo (``&freeStdFileObject''::Addr)
#endif
+ newHandle (Handle__ fo WriteHandle NoBuffering "stderr")
_ -> do ioError <- constructError "stderr"
- newHandle (ErrorHandle ioError)
+ newHandle (mkErrorHandle__ ioError)
)
\end{code}
openFileEx :: FilePath -> IOModeEx -> IO Handle
openFileEx f m = do
- ptr <- _ccall_ openFile f m'
- if ptr /= ``NULL'' then do
+ fo <- _ccall_ openFile f file_mode binary flush_on_close -- ConcHask: SAFE, won't block
+ if fo /= nullAddr then do
#ifndef __PARALLEL_HASKELL__
- fp <- makeForeignObj ptr ((``&freeFile'')::Addr)
- newHandle (htype fp Nothing False)
-#else
- newHandle (htype ptr Nothing False)
+ fo <- makeForeignObj fo ((``&freeFileObject'')::Addr)
#endif
+ (bm, bf_size) <- getBMode__ fo
+ mkBuffer__ fo bf_size
+ newHandle (Handle__ fo htype bm f)
else do
- ioError@(IOError hn iot msg) <- constructError "openFile"
- let
- improved_error -- a HACK, I guess
- = case iot of
- AlreadyExists -> IOError hn AlreadyExists (msg ++ ": " ++ f)
- NoSuchThing -> IOError hn NoSuchThing (msg ++ ": " ++ f)
- PermissionDenied -> IOError hn PermissionDenied (msg ++ ": " ++ f)
- _ -> ioError
- fail improved_error
+ constructErrorAndFailWithInfo "openFile" f
where
- imo = case m of
- BinaryMode imo -> imo
- TextMode imo -> imo
+ (imo, binary) =
+ case m of
+ BinaryMode imo -> (imo, 1)
+ TextMode imo -> (imo, 0)
- m' = case m of
- BinaryMode _ -> imo' ++ "b"
- TextMode imo -> imo'
+#ifndef __CONCURRENT_HASKELL__
+ file_mode = file_mode'
+#else
+ file_mode = file_mode' + 128{-Don't block on I/O-}
+#endif
- imo' =
+ (flush_on_close, file_mode') =
case imo of
- ReadMode -> "r"
- WriteMode -> "w"
- AppendMode -> "a"
- ReadWriteMode -> "r+"
+ AppendMode -> (1, 0)
+ WriteMode -> (1, 1)
+ ReadMode -> (0, 2)
+ ReadWriteMode -> (1, 3)
htype = case imo of
ReadMode -> ReadHandle
hClose :: Handle -> IO ()
hClose handle = do
- htype <- readHandle handle
- case htype of
+ handle_ <- readHandle handle
+ case haType__ handle_ of
ErrorHandle ioError -> do
- writeHandle handle htype
+ writeHandle handle handle_
fail ioError
ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle fp (buf,_) -> do
- (if buf /= ``NULL'' then
- _ccall_ free buf
- else
- return ())
- fp_a <- _casm_ `` %r = (char *)%0; '' fp
- if fp_a /= (``NULL''::Addr) then do
- -- Under what condition can this be NULL?
- rc <- _ccall_ closeFile fp
- {- We explicitly close a file object so that we can be told
- if there were any errors. Note that after @hClose@
- has been performed, the ForeignObj embedded in the Handle
- is still lying around in the heap, so care is taken
- to avoid closing the file object when the ForeignObj
- is finalised. -}
- if rc == 0 then do
-#ifndef __PARALLEL_HASKELL__
- -- Mark the foreign object data value as
- -- gone to the finaliser (freeFile())
- writeForeignObj fp ``NULL''
-#endif
- writeHandle handle ClosedHandle
- else do
- writeHandle handle htype
- constructErrorAndFail "hClose"
-
- else writeHandle handle htype
+ writeHandle handle handle_
+ ioe_closedHandle "hClose" handle
+ _ -> do
+ rc <- _ccall_ closeFile (haFO__ handle_) 1{-flush if you can-} -- ConcHask: SAFE, won't block
+ {- We explicitly close a file object so that we can be told
+ if there were any errors. Note that after @hClose@
+ has been performed, the ForeignObj embedded in the Handle
+ is still lying around in the heap, so care is taken
+ to avoid closing the file object when the ForeignObj
+ is finalised. (we overwrite the file ptr in the underlying
+ FileObject with a NULL as part of closeFile())
+ -}
+ if rc == 0
+ then
+ writeHandle handle (handle_{ haType__ = ClosedHandle,
+ haFO__ = nullFile__ })
+ else do
+ writeHandle handle handle_
+ constructErrorAndFail "hClose"
- other -> do
- let fp = filePtr other
- rc <- _ccall_ closeFile fp
- if rc == 0 then do
-#ifndef __PARALLEL_HASKELL__
- -- Mark the foreign object data
- writeForeignObj fp ``NULL''
-#endif
- writeHandle handle ClosedHandle
- else do
- writeHandle handle htype
- constructErrorAndFail "hClose"
\end{code}
Computation $hClose hdl$ makes handle {\em hdl} closed. Before the
\begin{code}
hFileSize :: Handle -> IO Integer
hFileSize handle = do
- htype <- readHandle handle
- case htype of
+ handle_ <- readHandle handle
+ case haType__ handle_ of
ErrorHandle ioError -> do
- writeHandle handle htype
+ writeHandle handle handle_
fail ioError
ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
+ writeHandle handle handle_
+ ioe_closedHandle "hFileSize" handle
+ SemiClosedHandle -> do
+ writeHandle handle handle_
+ ioe_closedHandle "hFileSize" handle
other ->
-- HACK! We build a unique MP_INT of the right shape to hold
-- a single unsigned word, and we let the C routine
_casm_ ``%r = 1;'' >>= \(I# hack#) ->
case int2Integer# hack# of
result@(J# _ _ d#) -> do
- let bogus_bounds = (error "fileSize"::(Int,Int))
- rc <- _ccall_ fileSize (filePtr other)
- (ByteArray bogus_bounds d#)
- writeHandle handle htype
+ rc <- _ccall_ fileSize (haFO__ handle_) d# -- ConcHask: SAFE, won't block
+ writeHandle handle handle_
if rc == 0 then
return result
else
constructErrorAndFail "hFileSize"
\end{code}
-For a readable handle {\em hdl}, computation $hIsEOF hdl$ returns
-$True$ if no further input can be taken from {\em hdl} or for a
+For a readable handle {\em hdl}, @hIsEOF hdl@ returns
+@True@ if no further input can be taken from @hdl@ or for a
physical file, if the current I/O position is equal to the length of
-the file. Otherwise, it returns $False$.
+the file. Otherwise, it returns @False@.
\begin{code}
hIsEOF :: Handle -> IO Bool
hIsEOF handle = do
- htype <- readHandle handle
- case htype of
- ErrorHandle ioError -> do
- writeHandle handle htype
- fail ioError
- ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- WriteHandle _ _ _ -> do
- writeHandle handle htype
- fail (IOError (Just handle) IllegalOperation
- "handle is not open for reading")
- AppendHandle _ _ _ -> do
- writeHandle handle htype
- fail (IOError (Just handle) IllegalOperation
- "handle is not open for reading")
- other -> do
- rc <- _ccall_ fileEOF (filePtr other)
- writeHandle handle (markHandle htype)
- case rc of
- 0 -> return False
- 1 -> return True
- _ -> constructErrorAndFail "hIsEOF"
+ handle_ <- wantReadableHandle "hIsEOF" handle
+ let fo = haFO__ handle_
+ rc <- mayBlock fo (_ccall_ fileEOF fo) -- ConcHask: UNSAFE, may block
+ writeHandle handle handle_
+ case rc of
+ 0 -> return False
+ 1 -> return True
+ _ -> constructErrorAndFail "hIsEOF"
isEOF :: IO Bool
isEOF = hIsEOF stdin
hSetBuffering handle mode =
case mode of
BlockBuffering (Just n)
- | n <= 0 -> fail (IOError (Just handle) InvalidArgument
- "illegal buffer size")
- other -> do
- htype <- readHandle handle
- if isMarked htype then do
- writeHandle handle htype
- fail (IOError (Just handle)
- UnsupportedOperation
- "can't set buffering for a dirty handle")
- else
- case htype of
- ErrorHandle ioError -> do
- writeHandle handle htype
- fail ioError
- ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- other -> do
- rc <- _ccall_ setBuffering (filePtr other) bsize
- if rc == 0 then
- writeHandle handle ((hcon other) (filePtr other)
- (Just mode) True)
- else do
- writeHandle handle htype
- constructErrorAndFail "hSetBuffering"
-
+ | n <= 0 -> fail (IOError (Just handle)
+ InvalidArgument
+ "hSetBuffering"
+ ("illegal buffer size " ++ showsPrec 9 n [])) -- 9 => should be parens'ified.
+ _ -> do
+ handle_ <- readHandle handle
+ case haType__ handle_ of
+ ErrorHandle ioError -> do
+ writeHandle handle handle_
+ fail ioError
+ ClosedHandle -> do
+ writeHandle handle handle_
+ ioe_closedHandle "hSetBuffering" handle
+ _ -> do
+ {- Note:
+ - we flush the old buffer regardless of whether
+ the new buffer could fit the contents of the old buffer
+ or not.
+ - allow a handle's buffering to change even if IO has
+ occurred (ANSI C spec. does not allow this, nor did
+ the previous implementation of IO.hSetBuffering).
+ - a non-standard extension is to allow the buffering
+ of semi-closed handles to change [sof 6/98]
+ -}
+ let fo = haFO__ handle_
+ rc <- mayBlock fo (_ccall_ setBuffering fo bsize) -- ConcHask: UNSAFE, may block
+ if rc == 0
+ then do
+ writeHandle handle (handle_{ haBufferMode__ = mode })
+ else do
+ -- Note: failure to change the buffer size will cause old buffer to be flushed.
+ writeHandle handle handle_
+ constructErrorAndFail "hSetBuffering"
where
- isMarked :: Handle__ -> Bool
- isMarked (ReadHandle fp m b) = b
- isMarked (WriteHandle fp m b) = b
- isMarked (AppendHandle fp m b) = b
- isMarked (ReadWriteHandle fp m b) = b
- isMarked _ = False
-
bsize :: Int
bsize = case mode of
- NoBuffering -> 0
- LineBuffering -> -1
- BlockBuffering Nothing -> -2
- BlockBuffering (Just n) -> n
-
-#ifndef __PARALLEL_HASKELL__
- hcon :: Handle__ -> (ForeignObj -> (Maybe BufferMode) -> Bool -> Handle__)
-#else
- hcon :: Handle__ -> (Addr -> (Maybe BufferMode) -> Bool -> Handle__)
-#endif
- hcon (ReadHandle _ _ _) = ReadHandle
- hcon (WriteHandle _ _ _) = WriteHandle
- hcon (AppendHandle _ _ _) = AppendHandle
- hcon (ReadWriteHandle _ _ _) = ReadWriteHandle
+ NoBuffering -> 0
+ LineBuffering -> -1
+ BlockBuffering Nothing -> -2
+ BlockBuffering (Just n) -> n
\end{code}
-Computation $flush hdl$ causes any items buffered for output in handle
-{\em hdl} to be sent immediately to the operating system.
+The action @hFlush hdl@ causes any items buffered for output
+in handle {\em hdl} to be sent immediately to the operating
+system.
\begin{code}
hFlush :: Handle -> IO ()
hFlush handle = do
- htype <- readHandle handle
- case htype of
- ErrorHandle ioError -> do
- writeHandle handle htype
- fail ioError
- ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- other -> do
- rc <- _ccall_ flushFile (filePtr other)
- writeHandle handle (markHandle htype)
- if rc == 0 then
- return ()
- else
- constructErrorAndFail "hFlush"
+ handle_ <- wantWriteableHandle "hFlush" handle
+ let fo = haFO__ handle_
+ rc <- mayBlock fo (_ccall_ flushFile fo) -- ConcHask: UNSAFE, may block
+ writeHandle handle handle_
+ if rc == 0 then
+ return ()
+ else
+ constructErrorAndFail "hFlush"
+
\end{code}
%*********************************************************
\begin{code}
-data HandlePosn = HandlePosn Handle Int
+data HandlePosn
+ = HandlePosn
+ Handle -- Q: should this be a weak or strong ref. to the handle?
+ Int
data SeekMode = AbsoluteSeek | RelativeSeek | SeekFromEnd
deriving (Eq, Ord, Ix, Enum, Read, Show)
\end{code}
-Computation $hGetPosn hdl$ returns the current I/O
+Computation @hGetPosn hdl@ returns the current I/O
position of {\em hdl} as an abstract position. Computation
$hSetPosn p$ sets the position of {\em hdl}
to a previously obtained position {\em p}.
\begin{code}
hGetPosn :: Handle -> IO HandlePosn
hGetPosn handle = do
- htype <- readHandle handle
- case htype of
- ErrorHandle ioError -> do
- writeHandle handle htype
- fail ioError
- ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- other -> do
- posn <- _ccall_ getFilePosn (filePtr other)
- writeHandle handle htype
- if posn /= -1 then
- return (HandlePosn handle posn)
- else
- constructErrorAndFail "hGetPosn"
+ handle_ <- wantSeekableHandle "hGetPosn" handle
+ posn <- _ccall_ getFilePosn (haFO__ handle_) -- ConcHask: SAFE, won't block
+ writeHandle handle handle_
+ if posn /= -1 then
+ return (HandlePosn handle posn)
+ else
+ constructErrorAndFail "hGetPosn"
hSetPosn :: HandlePosn -> IO ()
hSetPosn (HandlePosn handle posn) = do
- htype <- readHandle handle
- case htype of
- ErrorHandle ioError -> do
- writeHandle handle htype
- fail ioError
- ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- AppendHandle _ _ _ -> do
- writeHandle handle htype
- fail (IOError (Just handle) IllegalOperation "handle is not seekable")
- other -> do
- rc <- _ccall_ setFilePosn (filePtr other) posn
- writeHandle handle (markHandle htype)
- if rc == 0 then
- return ()
- else
- constructErrorAndFail "hSetPosn"
+ handle_ <- wantSeekableHandle "hSetPosn" handle -- not as silly as it looks: the handle may have been closed in the meantime.
+ let fo = haFO__ handle_
+ rc <- mayBlock fo (_ccall_ setFilePosn fo posn) -- ConcHask: UNSAFE, may block
+ writeHandle handle handle_
+ if rc == 0 then
+ return ()
+ else
+ constructErrorAndFail "hSetPosn"
\end{code}
-Computation $hSeek hdl mode i$ sets the position of handle
-{\em hdl} depending on $mode$. If {\em mode} is
+The action @hSeek hdl mode i@ sets the position of handle
+@hdl@ depending on @mode@. If @mode@ is
\begin{itemize}
-\item[{\bf AbsoluteSeek}] The position of {\em hdl} is set to {\em i}.
-\item[{\bf RelativeSeek}] The position of {\em hdl} is set to offset {\em i} from
+\item[{\bf AbsoluteSeek}] The position of @hdl@ is set to @i@.
+\item[{\bf RelativeSeek}] The position of @hdl@ is set to offset @i@ from
the current position.
-\item[{\bf SeekToEnd}] The position of {\em hdl} is set to offset {\em i} from
+\item[{\bf SeekFromEnd}] The position of @hdl@ is set to offset @i@ from
the end of the file.
-\item[{\bf SeekFromBeginning}] The position of {\em hdl} is set to offset {\em i} from
-the beginning of the file.
\end{itemize}
-Some handles may not be seekable $hIsSeekable$, or only support a
+Some handles may not be seekable (see @hIsSeekable@), or only support a
subset of the possible positioning operations (e.g. it may only be
possible to seek to the end of a tape, or to a positive offset from
the beginning or current position).
It is not possible to set a negative I/O position, or for a physical
file, an I/O position beyond the current end-of-file.
+Note:
+ - when seeking using @SeekFromEnd@, positive offsets (>=0) means seeking
+ at or past EOF.
+ - relative seeking on buffered handles can lead to non-obvious results.
+
\begin{code}
hSeek :: Handle -> SeekMode -> Integer -> IO ()
hSeek handle mode offset@(J# _ s# d#) = do
- htype <- readHandle handle
- case htype of
- ErrorHandle ioError -> do
- writeHandle handle htype
- fail ioError
- ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- AppendHandle _ _ _ -> do
- writeHandle handle htype
- fail (IOError (Just handle) IllegalOperation "handle is not seekable")
- other -> do
- rc <- _ccall_ seekFile (filePtr other) whence (I# s#)
- (ByteArray (0,0) d#)
- writeHandle handle (markHandle htype)
- if rc == 0 then
- return ()
- else
- constructErrorAndFail "hSeek"
+ handle_ <- wantSeekableHandle "hSeek" handle
+ let fo = haFO__ handle_
+ rc <- mayBlock fo (_ccall_ seekFile fo whence (I# s#) d#) -- ConcHask: UNSAFE, may block
+ writeHandle handle handle_
+ if rc == 0 then
+ return ()
+ else
+ constructErrorAndFail "hSeek"
where
whence :: Int
whence = case mode of
- AbsoluteSeek -> ``SEEK_SET''
- RelativeSeek -> ``SEEK_CUR''
- SeekFromEnd -> ``SEEK_END''
+ AbsoluteSeek -> 0
+ RelativeSeek -> 1
+ SeekFromEnd -> 2
\end{code}
%*********************************************************
\begin{code}
hIsOpen :: Handle -> IO Bool
hIsOpen handle = do
- htype <- readHandle handle
- case htype of
+ handle_ <- readHandle handle
+ case haType__ handle_ of
ErrorHandle ioError -> do
- writeHandle handle htype
+ writeHandle handle handle_
fail ioError
ClosedHandle -> do
- writeHandle handle htype
+ writeHandle handle handle_
return False
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
+ SemiClosedHandle -> do
+ writeHandle handle handle_
return False
- other -> do
- writeHandle handle htype
+ _ -> do
+ writeHandle handle handle_
return True
hIsClosed :: Handle -> IO Bool
hIsClosed handle = do
- htype <- readHandle handle
- case htype of
+ handle_ <- readHandle handle
+ case haType__ handle_ of
ErrorHandle ioError -> do
- writeHandle handle htype
+ writeHandle handle handle_
fail ioError
ClosedHandle -> do
- writeHandle handle htype
+ writeHandle handle handle_
return True
- other -> do
- writeHandle handle htype
+ _ -> do
+ writeHandle handle handle_
return False
+{- not defined, nor exported, but mentioned
+ here for documentation purposes:
+
+ hSemiClosed :: Handle -> IO Bool
+ hSemiClosed h = do
+ ho <- hIsOpen h
+ hc <- hIsClosed h
+ return (not (ho || hc))
+-}
+
hIsReadable :: Handle -> IO Bool
hIsReadable handle = do
- htype <- readHandle handle
- case htype of
+ handle_ <- readHandle handle
+ case haType__ handle_ of
ErrorHandle ioError -> do
- writeHandle handle htype
+ writeHandle handle handle_
fail ioError
ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- other -> do
- writeHandle handle htype
- return (isReadable other)
+ writeHandle handle handle_
+ ioe_closedHandle "hIsReadable" handle
+ SemiClosedHandle -> do
+ writeHandle handle handle_
+ ioe_closedHandle "hIsReadable" handle
+ htype -> do
+ writeHandle handle handle_
+ return (isReadable htype)
where
- isReadable (ReadHandle _ _ _) = True
- isReadable (ReadWriteHandle _ _ _) = True
- isReadable _ = False
+ isReadable ReadHandle = True
+ isReadable ReadWriteHandle = True
+ isReadable _ = False
hIsWritable :: Handle -> IO Bool
hIsWritable handle = do
- htype <- readHandle handle
- case htype of
+ handle_ <- readHandle handle
+ case haType__ handle_ of
ErrorHandle ioError -> do
- writeHandle handle htype
+ writeHandle handle handle_
fail ioError
ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- other -> do
- writeHandle handle htype
- return (isWritable other)
+ writeHandle handle handle_
+ ioe_closedHandle "hIsWritable" handle
+ SemiClosedHandle -> do
+ writeHandle handle handle_
+ ioe_closedHandle "hIsWritable" handle
+ htype -> do
+ writeHandle handle handle_
+ return (isWritable htype)
where
- isWritable (AppendHandle _ _ _) = True
- isWritable (WriteHandle _ _ _) = True
- isWritable (ReadWriteHandle _ _ _) = True
- isWritable _ = False
-
-getBufferMode :: Handle__ -> IO Handle__
-getBufferMode htype =
- case bufferMode htype of
- Just x -> return htype
- Nothing -> do
- rc <- _ccall_ getBufferMode (filePtr htype)
- let
- mode =
- case rc of
- 0 -> Just NoBuffering
- -1 -> Just LineBuffering
- -2 -> Just (BlockBuffering Nothing)
- -3 -> Nothing
- n -> Just (BlockBuffering (Just n))
- return (case htype of
- ReadHandle fp _ b -> ReadHandle fp mode b
- WriteHandle fp _ b -> WriteHandle fp mode b
- AppendHandle fp _ b -> AppendHandle fp mode b
- ReadWriteHandle fp _ b -> ReadWriteHandle fp mode b)
-
-hIsBlockBuffered :: Handle -> IO (Bool,Maybe Int)
-hIsBlockBuffered handle = do
- htype <- readHandle handle
- case htype of
- ErrorHandle ioError -> do
- writeHandle handle htype
- fail ioError
- ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- other -> do
- other <- getBufferMode other
- case bufferMode other of
- Just (BlockBuffering size) -> do
- writeHandle handle other
- return (True, size)
- Just _ -> do
- writeHandle handle other
- return (False, Nothing)
- Nothing ->
- constructErrorAndFail "hIsBlockBuffered"
-
-hIsLineBuffered :: Handle -> IO Bool
-hIsLineBuffered handle = do
- htype <- readHandle handle
- case htype of
- ErrorHandle ioError -> do
- writeHandle handle htype
- fail ioError
- ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- other -> do
- other <- getBufferMode other
- case bufferMode other of
- Just LineBuffering -> do
- writeHandle handle other
- return True
- Just _ -> do
- writeHandle handle other
- return False
- Nothing ->
- constructErrorAndFail "hIsLineBuffered"
-
-hIsNotBuffered :: Handle -> IO Bool
-hIsNotBuffered handle = do
- htype <- readHandle handle
- case htype of
- ErrorHandle ioError -> do
- writeHandle handle htype
- fail ioError
- ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- other -> do
- other <- getBufferMode other
- case bufferMode other of
- Just NoBuffering -> do
- writeHandle handle other
- return True
- Just _ -> do
- writeHandle handle other
- return False
- Nothing ->
- constructErrorAndFail "hIsNotBuffered"
+ isWritable AppendHandle = True
+ isWritable WriteHandle = True
+ isWritable ReadWriteHandle = True
+ isWritable _ = False
+
+
+#ifndef __PARALLEL_HASKELL__
+getBMode__ :: ForeignObj -> IO (BufferMode, Int)
+#else
+getBMode__ :: Addr -> IO (BufferMode, Int)
+#endif
+getBMode__ fo = do
+ rc <- _ccall_ getBufferMode fo -- ConcHask: SAFE, won't block
+ case (rc::Int) of
+ 0 -> return (NoBuffering, 0)
+ -1 -> return (LineBuffering, default_buffer_size)
+ -2 -> return (BlockBuffering Nothing, default_buffer_size)
+ -3 -> return (NoBuffering, 0) -- only happens on un-stat()able files.
+ n -> return (BlockBuffering (Just n), n)
+ where
+ default_buffer_size :: Int
+ default_buffer_size = (``BUFSIZ'' - 1)
+\end{code}
+Querying how a handle buffers its data:
+
+\begin{code}
hGetBuffering :: Handle -> IO BufferMode
hGetBuffering handle = do
- htype <- readHandle handle
- case htype of
+ handle_ <- readHandle handle
+ case haType__ handle_ of
ErrorHandle ioError -> do
- writeHandle handle htype
+ writeHandle handle handle_
fail ioError
ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- other -> do
- other <- getBufferMode other
- case bufferMode other of
- Just v -> do
- writeHandle handle other
- return v
- Nothing ->
- constructErrorAndFail "hGetBuffering"
+ writeHandle handle handle_
+ ioe_closedHandle "hGetBuffering" handle
+ _ -> do
+ {-
+ We're being non-standard here, and allow the buffering
+ of a semi-closed handle to be queried. -- sof 6/98
+ -}
+ let v = haBufferMode__ handle_
+ writeHandle handle handle_
+ return v -- could be stricter..
+\end{code}
+
+\begin{code}
hIsSeekable :: Handle -> IO Bool
hIsSeekable handle = do
- htype <- readHandle handle
- case htype of
+ handle_ <- readHandle handle
+ case haType__ handle_ of
ErrorHandle ioError -> do
- writeHandle handle htype
+ writeHandle handle handle_
fail ioError
ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- AppendHandle _ _ _ -> do
- writeHandle handle htype
+ writeHandle handle handle_
+ ioe_closedHandle "hIsSeekable" handle
+ SemiClosedHandle -> do
+ writeHandle handle handle_
+ ioe_closedHandle "hIsSeekable" handle
+ AppendHandle -> do
+ writeHandle handle handle_
return False
other -> do
- rc <- _ccall_ seekFileP (filePtr other)
- writeHandle handle htype
+ rc <- _ccall_ seekFileP (haFO__ handle_) -- ConcHask: SAFE, won't block
+ writeHandle handle handle_
case rc of
0 -> return False
1 -> return True
%*********************************************************
%* *
+\subsection{Changing echo status}
+%* *
+%*********************************************************
+
+Non-standard GHC extension is to allow the echoing status
+of a handles connected to terminals to be reconfigured:
+
+\begin{code}
+hSetEcho :: Handle -> Bool -> IO ()
+hSetEcho hdl on = do
+ isT <- hIsTerminalDevice hdl
+ if not isT
+ then return ()
+ else do
+ handle_ <- readHandle hdl
+ case haType__ handle_ of
+ ErrorHandle ioError -> do
+ writeHandle hdl handle_
+ fail ioError
+ ClosedHandle -> do
+ writeHandle hdl handle_
+ ioe_closedHandle "hSetEcho" hdl
+ other -> do
+ rc <- _ccall_ setTerminalEcho (haFO__ handle_) (if on then 1 else 0) -- ConcHask: SAFE, won't block
+ writeHandle hdl handle_
+ if rc /= -1
+ then return ()
+ else constructErrorAndFail "hSetEcho"
+
+hGetEcho :: Handle -> IO Bool
+hGetEcho hdl = do
+ isT <- hIsTerminalDevice hdl
+ if not isT
+ then return False
+ else do
+ handle_ <- readHandle hdl
+ case haType__ handle_ of
+ ErrorHandle ioError -> do
+ writeHandle hdl handle_
+ fail ioError
+ ClosedHandle -> do
+ writeHandle hdl handle_
+ ioe_closedHandle "hGetEcho" hdl
+ other -> do
+ rc <- _ccall_ getTerminalEcho (haFO__ handle_) -- ConcHask: SAFE, won't block
+ writeHandle hdl handle_
+ case rc of
+ 1 -> return True
+ 0 -> return False
+ _ -> constructErrorAndFail "hSetEcho"
+
+hIsTerminalDevice :: Handle -> IO Bool
+hIsTerminalDevice hdl = do
+ handle_ <- readHandle hdl
+ case haType__ handle_ of
+ ErrorHandle ioError -> do
+ writeHandle hdl handle_
+ fail ioError
+ ClosedHandle -> do
+ writeHandle hdl handle_
+ ioe_closedHandle "hIsTerminalDevice" hdl
+ other -> do
+ rc <- _ccall_ isTerminalDevice (haFO__ handle_) -- ConcHask: SAFE, won't block
+ writeHandle hdl handle_
+ case rc of
+ 1 -> return True
+ 0 -> return False
+ _ -> constructErrorAndFail "hIsTerminalDevice"
+\end{code}
+
+\begin{code}
+hConnectTerms :: Handle -> Handle -> IO ()
+hConnectTerms hW hR = hConnectHdl_ hW hR 1{-check if they're both coming connected to ttys-}
+
+hConnectTo :: Handle -> Handle -> IO ()
+hConnectTo hW hR = hConnectHdl_ hW hR 0{-connect regardless-}
+
+hConnectHdl_ :: Handle -> Handle -> Int -> IO ()
+hConnectHdl_ hW hR is_tty = do
+ hW_ <- wantWriteableHandle "hConnectTo" hW
+ hR_ <- wantReadableHandle "hConnectTo" hR
+ _ccall_ setConnectedTo (haFO__ hR_) (haFO__ hW_) is_tty -- ConcHask: SAFE, won't block
+ writeHandle hR hR_
+ writeHandle hW hW_
+
+\end{code}
+
+As an extension, we also allow characters to be pushed back.
+Like ANSI C stdio, we guarantee no more than one character of
+pushback. (For unbuffered channels, the (default) push-back limit is
+2 chars tho.)
+
+\begin{code}
+hUngetChar :: Handle -> Char -> IO ()
+hUngetChar handle c = do
+ handle_ <- wantReadableHandle "hLookAhead" handle
+ rc <- _ccall_ ungetChar (haFO__ handle_) c -- ConcHask: SAFE, won't block
+ writeHandle handle handle_
+ if rc == (-1)
+ then constructErrorAndFail "hUngetChar"
+ else return ()
+
+\end{code}
+
+
+Hoisting files in in one go is sometimes useful, so we support
+this as an extension:
+
+\begin{code}
+-- in one go, read file into an externally allocated buffer.
+slurpFile :: FilePath -> IO (Addr, Int)
+slurpFile fname = do
+ hdl <- openFile fname ReadMode
+ sz <- hFileSize hdl
+ if sz > toInteger (maxBound::Int) then
+ fail (userError "slurpFile: file too big")
+ else do
+ let sz_i = fromInteger sz
+ chunk <- _ccall_ allocMemory__ (sz_i::Int)
+ if chunk == nullAddr
+ then do
+ hClose hdl
+ constructErrorAndFail "slurpFile"
+ else do
+ handle_ <- readHandle hdl
+ let fo = haFO__ handle_
+ rc <- mayBlock fo (_ccall_ readChunk fo chunk sz_i) -- ConcHask: UNSAFE, may block.
+ writeHandle hdl handle_
+ hClose hdl
+ if rc < 0
+ then constructErrorAndFail "slurpFile"
+ else return (chunk, rc)
+
+hFillBufBA :: Handle -> ByteArray Int -> Int -> IO Int
+hFillBufBA handle buf sz
+ | sz <= 0 = fail (IOError (Just handle)
+ InvalidArgument
+ "hFillBufBA"
+ ("illegal buffer size " ++ showsPrec 9 sz [])) -- 9 => should be parens'ified.
+ | otherwise = do
+ handle_ <- wantReadableHandle "hFillBufBA" handle
+ let fo = haFO__ handle_
+ rc <- mayBlock fo (_ccall_ readChunk fo buf sz) -- ConcHask: UNSAFE, may block.
+ writeHandle handle handle_
+ if rc >= 0
+ then return rc
+ else constructErrorAndFail "hFillBufBA"
+
+hFillBuf :: Handle -> Addr -> Int -> IO Int
+hFillBuf handle buf sz
+ | sz <= 0 = fail (IOError (Just handle)
+ InvalidArgument
+ "hFillBuf"
+ ("illegal buffer size " ++ showsPrec 9 sz [])) -- 9 => should be parens'ified.
+ | otherwise = do
+ handle_ <- wantReadableHandle "hFillBuf" handle
+ let fo = haFO__ handle_
+ rc <- mayBlock fo (_ccall_ readChunk fo buf sz) -- ConcHask: UNSAFE, may block.
+ writeHandle handle handle_
+ if rc >= 0
+ then return rc
+ else constructErrorAndFail "hFillBuf"
+
+\end{code}
+
+The @hPutBuf hdl buf len@ action writes an already packed sequence of
+bytes to the file/channel managed by @hdl@ - non-standard.
+
+\begin{code}
+hPutBuf :: Handle -> Addr -> Int -> IO ()
+hPutBuf handle buf len = do
+ handle_ <- wantWriteableHandle "hPutBuf" handle
+ let fo = haFO__ handle_
+ rc <- mayBlock fo (_ccall_ writeBuf fo buf len) -- ConcHask: UNSAFE, may block.
+ writeHandle handle handle_
+ if rc == 0
+ then return ()
+ else constructErrorAndFail "hPutBuf"
+
+hPutBufBA :: Handle -> ByteArray Int -> Int -> IO ()
+hPutBufBA handle buf len = do
+ handle_ <- wantWriteableHandle "hPutBufBA" handle
+ let fo = haFO__ handle_
+ rc <- mayBlock fo (_ccall_ writeBufBA fo buf len) -- ConcHask: UNSAFE, may block.
+ writeHandle handle handle_
+ if rc == 0
+ then return ()
+ else constructErrorAndFail "hPutBuf"
+\end{code}
+
+Sometimes it's useful to get at the file descriptor that
+the Handle contains..
+
+\begin{code}
+getHandleFd :: Handle -> IO Int
+getHandleFd handle = do
+ handle_ <- readHandle handle
+ case (haType__ handle_) of
+ ErrorHandle ioError -> do
+ writeHandle handle handle_
+ fail ioError
+ ClosedHandle -> do
+ writeHandle handle handle_
+ ioe_closedHandle "getHandleFd" handle
+ _ -> do
+ fd <- _ccall_ getFileFd (haFO__ handle_)
+ writeHandle handle handle_
+ return fd
+\end{code}
+
+
+%*********************************************************
+%* *
\subsection{Miscellaneous}
%* *
%*********************************************************
-These two functions are meant to get things out of @IOErrors@. They don't!
+These three functions are meant to get things out of @IOErrors@.
+
+(ToDo: improve!)
\begin{code}
ioeGetFileName :: IOError -> Maybe FilePath
ioeGetErrorString :: IOError -> String
ioeGetHandle :: IOError -> Maybe Handle
-ioeGetHandle (IOError h _ _) = h
-ioeGetErrorString (IOError _ iot str) =
+ioeGetHandle (IOError h _ _ _) = h
+ioeGetErrorString (IOError _ iot _ str) =
case iot of
EOF -> "end of file"
_ -> str
-ioeGetFileName (IOError _ _ str) =
+ioeGetFileName (IOError _ _ _ str) =
case span (/=':') str of
(fs,[]) -> Nothing
(fs,_) -> Just fs
\end{code}
-Internal function for creating an @IOError@ representing the
-access of a closed file.
-
-\begin{code}
-
-ioe_closedHandle :: Handle -> IO a
-ioe_closedHandle h = fail (IOError (Just h) IllegalOperation "handle is closed")
-\end{code}
-
A number of operations want to get at a readable or writeable handle, and fail
if it isn't:
\begin{code}
-wantReadableHandle :: Handle -> IO Handle__
-wantReadableHandle handle = do
- htype <- readHandle handle
- case htype of
+wantReadableHandle :: String -> Handle -> IO Handle__
+wantReadableHandle fun handle = do
+ handle_ <- readHandle handle
+ case haType__ handle_ of
+ ErrorHandle ioError -> do
+ writeHandle handle handle_
+ fail ioError
+ ClosedHandle -> do
+ writeHandle handle handle_
+ ioe_closedHandle fun handle
+ SemiClosedHandle -> do
+ writeHandle handle handle_
+ ioe_closedHandle fun handle
+ AppendHandle -> do
+ writeHandle handle handle_
+ fail not_readable_error
+ WriteHandle -> do
+ writeHandle handle handle_
+ fail not_readable_error
+ other -> return handle_
+ where
+ not_readable_error =
+ IOError (Just handle) IllegalOperation fun
+ ("handle is not open for reading")
+
+wantWriteableHandle :: String -> Handle -> IO Handle__
+wantWriteableHandle fun handle = do
+ handle_ <- readHandle handle
+ case haType__ handle_ of
ErrorHandle ioError -> do
- writeHandle handle htype
+ writeHandle handle handle_
fail ioError
ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- AppendHandle _ _ _ -> do
- writeHandle handle htype
- fail (IOError (Just handle) IllegalOperation
- "handle is not open for reading")
- WriteHandle _ _ _ -> do
- writeHandle handle htype
- fail (IOError (Just handle) IllegalOperation
- "handle is not open for reading")
- other -> return other
-
-wantWriteableHandle :: Handle
- -> IO Handle__
-wantWriteableHandle handle = do
- htype <- readHandle handle
- case htype of
+ writeHandle handle handle_
+ ioe_closedHandle fun handle
+ SemiClosedHandle -> do
+ writeHandle handle handle_
+ ioe_closedHandle fun handle
+ ReadHandle -> do
+ writeHandle handle handle_
+ fail not_writeable_error
+ other -> return handle_
+ where
+ not_writeable_error =
+ IOError (Just handle) IllegalOperation fun
+ ("handle is not open for writing")
+
+wantSeekableHandle :: String -> Handle -> IO Handle__
+wantSeekableHandle fun handle = do
+ handle_ <- readHandle handle
+ case haType__ handle_ of
ErrorHandle ioError -> do
- writeHandle handle htype
+ writeHandle handle handle_
fail ioError
ClosedHandle -> do
- writeHandle handle htype
- ioe_closedHandle handle
- SemiClosedHandle _ _ -> do
- writeHandle handle htype
- ioe_closedHandle handle
- ReadHandle _ _ _ -> do
- writeHandle handle htype
- fail (IOError (Just handle) IllegalOperation "handle is not open for writing")
- other -> return other
+ writeHandle handle handle_
+ ioe_closedHandle fun handle
+ SemiClosedHandle -> do
+ writeHandle handle handle_
+ ioe_closedHandle fun handle
+ AppendHandle -> do
+ writeHandle handle handle_
+ fail not_seekable_error
+ _ -> return handle_
+ where
+ not_seekable_error =
+ IOError (Just handle)
+ IllegalOperation fun
+ ("handle is not seekable")
+
+\end{code}
+
+Internal function for creating an @IOError@ representing the
+access to a closed file.
+
+\begin{code}
+ioe_closedHandle :: String -> Handle -> IO a
+ioe_closedHandle fun h = fail (IOError (Just h) IllegalOperation fun "handle is closed")
+\end{code}
+Internal helper functions for Concurrent Haskell implementation
+of IO:
+
+\begin{code}
+#ifndef __PARALLEL_HASKELL__
+mayBlock :: ForeignObj -> IO Int -> IO Int
+#else
+mayBlock :: Addr -> IO Int -> IO Int
+#endif
+
+#ifndef __CONCURRENT_HASKELL__
+mayBlock _ act = act
+#else
+mayBlock fo act = do
+ rc <- act
+ case rc of
+ -5 -> do -- (possibly blocking) read
+ fd <- _ccall_ getFileFd fo
+ threadWaitRead fd
+ _ccall_ clearNonBlockingIOFlag__ fo -- force read to happen this time.
+ mayBlock fo act -- input available, re-try
+ -6 -> do -- (possibly blocking) write
+ fd <- _ccall_ getFileFd fo
+ threadWaitWrite fd
+ _ccall_ clearNonBlockingIOFlag__ fo -- force write to happen this time.
+ mayBlock fo act -- output possible
+ -7 -> do -- (possibly blocking) write on connected handle
+ fd <- _ccall_ getConnFileFd fo
+ threadWaitWrite fd
+ _ccall_ clearConnNonBlockingIOFlag__ fo -- force write to happen this time.
+ mayBlock fo act -- output possible
+ _ -> do
+ _ccall_ setNonBlockingIOFlag__ fo -- reset file object.
+ _ccall_ setConnNonBlockingIOFlag__ fo -- reset (connected) file object.
+ return rc
+
+#endif
\end{code}
+
+
projects / ghc-hetmet.git / blobdiff