\begin{code}
{-# OPTIONS -fno-implicit-prelude -#include "cbits/stgio.h" #-}
+#ifndef BODY /* Hugs just includes this in PreludeBuiltin so no header needed */
module IO (
Handle, -- abstract, instance of: Eq, Show.
HandlePosn(..), -- abstract, instance of: Eq, Show.
-- Non-standard extension (but will hopefully become standard with 1.5) is
-- to export the Prelude io functions via IO (in addition to exporting them
-- from the prelude...for now.)
+ IO,
+ FilePath, -- :: String
+ IOError,
+ ioError, -- :: IOError -> IO a
+ userError, -- :: String -> IOError
+ catch, -- :: IO a -> (IOError -> IO a) -> IO a
+ interact, -- :: (String -> String) -> IO ()
+
putChar, -- :: Char -> IO ()
putStr, -- :: String -> IO ()
putStrLn, -- :: String -> IO ()
getChar, -- :: IO Char
getLine, -- :: IO String
getContents, -- :: IO String
- interact, -- :: (String -> String) -> IO ()
readFile, -- :: FilePath -> IO String
writeFile, -- :: FilePath -> String -> IO ()
appendFile, -- :: FilePath -> String -> IO ()
readIO, -- :: Read a => String -> IO a
readLn, -- :: Read a => IO a
- FilePath, -- :: String
- fail, -- :: IOError -> IO a
- catch, -- :: IO a -> (IOError -> IO a) -> IO a
- userError, -- :: String -> IOError
-
- IO, -- non-standard, amazingly enough.
- IOError, -- ditto
-- extensions
hPutBuf,
+#ifndef __HUGS__
hPutBufBA,
+#endif
slurpFile
) where
+#ifdef __HUGS__
+
+import PreludeBuiltin
+
+#else
+
+--import PrelST
import PrelBase
import PrelIOBase
import PrelRead ( readParen, Read(..), reads, lex,
readIO
)
---import PrelNum ( toInteger )
-import PrelBounded () -- Bounded Int instance.
-import PrelEither ( Either(..) )
+import PrelShow
+import PrelMaybe ( Either(..), Maybe(..) )
import PrelAddr ( Addr(..), nullAddr )
import PrelArr ( ByteArray )
import PrelPack ( unpackNBytesAccST )
+import PrelException ( ioError, catch )
#ifndef __PARALLEL_HASKELL__
import PrelForeign ( ForeignObj )
import Char ( ord, chr )
+#endif /* ndef __HUGS__ */
+#endif /* ndef BODY */
+
+#ifndef HEAD
+
+#ifdef __HUGS__
+#define cat2(x,y) x##y
+#define CCALL(fun) cat2(prim_,fun)
+#define __CONCURRENT_HASKELL__
+#define stToIO id
+#define unpackNBytesAccST primUnpackCStringAcc
+#else
+#define CCALL(fun) _ccall_ fun
+#define ref_freeStdFileObject (``&freeStdFileObject''::Addr)
+#define ref_freeFileObject (``&freeFileObject''::Addr)
+#define const_BUFSIZ ``BUFSIZ''
+#endif
+
\end{code}
Standard instances for @Handle@:
-- Type declared in IOBase, instance here because it
-- depends on PrelRead.(Read Maybe) instance.
instance Read BufferMode where
- readsPrec p =
+ readsPrec _ =
readParen False
(\r -> let lr = lex r
in
hReady h = hWaitForInput h 0
hWaitForInput :: Handle -> Int -> IO Bool
-hWaitForInput handle msecs = do
- handle_ <- wantReadableHandle "hWaitForInput" handle
- rc <- _ccall_ inputReady (haFO__ handle_) (msecs::Int) -- ConcHask: SAFE, won't block
- writeHandle handle handle_
- case rc of
+hWaitForInput handle msecs =
+ wantReadableHandle "hWaitForInput" handle $ \ handle_ -> do
+ rc <- CCALL(inputReady) (haFO__ handle_) (msecs::Int) -- ConcHask: SAFE, won't block
+ case (rc::Int) of
0 -> return False
1 -> return True
_ -> constructErrorAndFail "hWaitForInput"
\begin{code}
hGetChar :: Handle -> IO Char
-hGetChar handle = do
- handle_ <- wantReadableHandle "hGetChar" handle
+hGetChar handle =
+ wantReadableHandle "hGetChar" handle $ \ handle_ -> do
let fo = haFO__ handle_
- intc <- mayBlock fo (_ccall_ fileGetc fo) -- ConcHask: UNSAFE, may block
- writeHandle handle handle_
- if intc /= (-1)
+ intc <- mayBlock fo (CCALL(fileGetc) fo) -- ConcHask: UNSAFE, may block
+ if intc /= ((-1)::Int)
then return (chr intc)
else constructErrorAndFail "hGetChar"
+{-
+ If EOF is reached before EOL is encountered, ignore the
+ EOF and return the partial line. Next attempt at calling
+ hGetLine on the handle will yield an EOF IO exception though.
+-}
hGetLine :: Handle -> IO String
hGetLine h = do
c <- hGetChar h
- if c == '\n'
- then return ""
+ if c == '\n' then
+ return ""
else do
- s <- hGetLine h
- return (c:s)
+ l <- getRest
+ return (c:l)
+ where
+ getRest = do
+ c <-
+ catch
+ (hGetChar h)
+ (\ err -> do
+ if isEOFError err then
+ return '\n'
+ else
+ ioError err)
+ if c == '\n' then
+ return ""
+ else do
+ s <- getRest
+ return (c:s)
\end{code}
\begin{code}
hLookAhead :: Handle -> IO Char
-hLookAhead handle = do
- handle_ <- wantReadableHandle "hLookAhead" handle
+hLookAhead handle =
+ wantReadableHandle "hLookAhead" handle $ \ handle_ -> do
let fo = haFO__ handle_
- intc <- mayBlock fo (_ccall_ fileLookAhead fo) -- ConcHask: UNSAFE, may block
- writeHandle handle handle_
+ intc <- mayBlock fo (CCALL(fileLookAhead) fo) -- ConcHask: UNSAFE, may block
if intc /= (-1)
then return (chr intc)
else constructErrorAndFail "hLookAhead"
\begin{code}
hGetContents :: Handle -> IO String
-hGetContents handle = do
- handle_ <- wantReadableHandle "hGetContents" handle
- {-
- To avoid introducing an extra layer of buffering here,
- we provide three lazy read methods, based on character,
- line, and block buffering.
- -}
- writeHandle handle (handle_{ haType__ = SemiClosedHandle })
- case (haBufferMode__ handle_) of
- LineBuffering -> unsafeInterleaveIO (lazyReadLine handle (haFO__ handle_))
- BlockBuffering _ -> unsafeInterleaveIO (lazyReadBlock handle (haFO__ handle_))
- NoBuffering -> unsafeInterleaveIO (lazyReadChar handle (haFO__ handle_))
-
+hGetContents handle =
+ -- can't use wantReadableHandle here, because we want to side effect
+ -- the handle.
+ withHandle handle $ \ handle_ -> do
+ case haType__ handle_ of
+ ErrorHandle theError -> ioError theError
+ ClosedHandle -> ioe_closedHandle "hGetContents" handle
+ SemiClosedHandle -> ioe_closedHandle "hGetContents" handle
+ AppendHandle -> ioError not_readable_error
+ WriteHandle -> ioError not_readable_error
+ _ -> do
+ {-
+ To avoid introducing an extra layer of buffering here,
+ we provide three lazy read methods, based on character,
+ line, and block buffering.
+ -}
+ let handle_' = handle_{ haType__ = SemiClosedHandle }
+ case (haBufferMode__ handle_) of
+ LineBuffering -> do
+ str <- unsafeInterleaveIO (lazyReadLine handle (haFO__ handle_))
+ return (handle_', str)
+ BlockBuffering _ -> do
+ str <- unsafeInterleaveIO (lazyReadBlock handle (haFO__ handle_))
+ return (handle_', str)
+ NoBuffering -> do
+ str <- unsafeInterleaveIO (lazyReadChar handle (haFO__ handle_))
+ return (handle_', str)
+ where
+ not_readable_error =
+ IOError (Just handle) IllegalOperation "hGetContents"
+ ("handle is not open for reading")
\end{code}
Note that someone may close the semi-closed handle (or change its buffering),
#endif
lazyReadBlock handle fo = do
- buf <- _ccall_ getBufStart fo (0::Int)
- bytes <- mayBlock fo (_ccall_ readBlock fo) -- ConcHask: UNSAFE, may block.
- case bytes of
+ buf <- CCALL(getBufStart) fo (0::Int)
+ bytes <- mayBlock fo (CCALL(readBlock) fo) -- ConcHask: UNSAFE, may block.
+ case (bytes::Int) of
-3 -> -- buffering has been turned off, use lazyReadChar instead
lazyReadChar handle fo
-2 -> return ""
- -1 -> do -- an error occurred, close the handle
- handle_ <- readHandle handle
- _ccall_ closeFile (haFO__ handle_) 0{-don't bother flushing-} -- ConcHask: SAFE, won't block.
- writeHandle handle (handle_ { haType__ = ClosedHandle,
- haFO__ = nullFile__ })
- return ""
+ -1 -> -- an error occurred, close the handle
+ withHandle handle $ \ handle_ -> do
+ CCALL(closeFile) (haFO__ handle_) (0::Int){-don't bother flushing-} -- ConcHask: SAFE, won't block.
+ return (handle_ { haType__ = ClosedHandle,
+ haFO__ = nullFile__ },
+ "")
_ -> do
more <- unsafeInterleaveIO (lazyReadBlock handle fo)
stToIO (unpackNBytesAccST buf bytes more)
lazyReadLine handle fo = do
- bytes <- mayBlock fo (_ccall_ readLine fo) -- ConcHask: UNSAFE, may block.
- case bytes of
+ bytes <- mayBlock fo (CCALL(readLine) fo) -- ConcHask: UNSAFE, may block.
+ case (bytes::Int) of
-3 -> -- buffering has been turned off, use lazyReadChar instead
lazyReadChar handle fo
-2 -> return "" -- handle closed by someone else, stop reading.
- -1 -> do -- an error occurred, close the handle
- handle_ <- readHandle handle
- _ccall_ closeFile (haFO__ handle_) 0{- don't bother flushing-} -- ConcHask: SAFE, won't block
- writeHandle handle (handle_ { haType__ = ClosedHandle,
- haFO__ = nullFile__ })
- return ""
+ -1 -> -- an error occurred, close the handle
+ withHandle handle $ \ handle_ -> do
+ CCALL(closeFile) (haFO__ handle_) (0::Int){- don't bother flushing-} -- ConcHask: SAFE, won't block
+ return (handle_ { haType__ = ClosedHandle,
+ haFO__ = nullFile__ },
+ "")
_ -> do
more <- unsafeInterleaveIO (lazyReadLine handle fo)
- buf <- _ccall_ getBufStart fo bytes -- ConcHask: won't block
+ buf <- CCALL(getBufStart) fo bytes -- ConcHask: won't block
stToIO (unpackNBytesAccST buf bytes more)
lazyReadChar handle fo = do
- char <- mayBlock fo (_ccall_ readChar fo) -- ConcHask: UNSAFE, may block.
- case char of
+ char <- mayBlock fo (CCALL(readChar) fo) -- ConcHask: UNSAFE, may block.
+ case (char::Int) of
-4 -> -- buffering is now block-buffered, use lazyReadBlock instead
lazyReadBlock handle fo
-3 -> -- buffering is now line-buffered, use lazyReadLine instead
lazyReadLine handle fo
-2 -> return ""
- -1 -> do -- error, silently close handle.
- handle_ <- readHandle handle
- _ccall_ closeFile (haFO__ handle_) 0{-don't bother flusing-} -- ConcHask: SAFE, won't block
- writeHandle handle (handle_{ haType__ = ClosedHandle,
- haFO__ = nullFile__ })
- return ""
+ -1 -> -- error, silently close handle.
+ withHandle handle $ \ handle_ -> do
+ CCALL(closeFile) (haFO__ handle_) (0::Int){-don't bother flusing-} -- ConcHask: SAFE, won't block
+ return (handle_{ haType__ = ClosedHandle,
+ haFO__ = nullFile__ },
+ "")
_ -> do
more <- unsafeInterleaveIO (lazyReadChar handle fo)
return (chr char : more)
\begin{code}
hPutChar :: Handle -> Char -> IO ()
-hPutChar handle c = do
- handle_ <- wantWriteableHandle "hPutChar" handle
+hPutChar handle c =
+ wantWriteableHandle "hPutChar" handle $ \ handle_ -> do
let fo = haFO__ handle_
- flushConnectedHandle fo
- rc <- mayBlock fo (_ccall_ filePutc fo c) -- ConcHask: UNSAFE, may block.
- writeHandle handle handle_
+ flushConnectedBuf fo
+ rc <- mayBlock fo (CCALL(filePutc) fo c) -- ConcHask: UNSAFE, may block.
if rc == 0
then return ()
else constructErrorAndFail "hPutChar"
\begin{code}
hPutStr :: Handle -> String -> IO ()
-hPutStr handle str = do
- handle_ <- wantWriteableHandle "hPutStr" handle
+hPutStr handle str =
+ wantWriteableHandle "hPutStr" handle $ \ handle_ -> do
let fo = haFO__ handle_
- flushConnectedHandle fo
+ flushConnectedBuf fo
case haBufferMode__ handle_ of
LineBuffering -> do
- buf <- _ccall_ getWriteableBuf fo
- pos <- _ccall_ getBufWPtr fo
- bsz <- _ccall_ getBufSize fo
+ buf <- CCALL(getWriteableBuf) fo
+ pos <- CCALL(getBufWPtr) fo
+ bsz <- CCALL(getBufSize) fo
writeLines fo buf bsz pos str
BlockBuffering _ -> do
- buf <- _ccall_ getWriteableBuf fo
- pos <- _ccall_ getBufWPtr fo
- bsz <- _ccall_ getBufSize fo
+ buf <- CCALL(getWriteableBuf) fo
+ pos <- CCALL(getBufWPtr) fo
+ bsz <- CCALL(getBufSize) fo
writeBlocks fo buf bsz pos str
NoBuffering -> do
writeChars fo str
- writeHandle handle handle_
-
\end{code}
Going across the border between Haskell and C is relatively costly,
before passing the external write routine a pointer to the buffer.
\begin{code}
+#ifdef __HUGS__
+
+#ifdef __CONCURRENT_HASKELL__
+/* See comment in shoveString below for explanation */
+#warning delayed update of buffer disnae work with killThread
+#endif
#ifndef __PARALLEL_HASKELL__
writeLines :: ForeignObj -> Addr -> Int -> Int -> String -> IO ()
#else
writeLines :: Addr -> Addr -> Int -> Int -> String -> IO ()
#endif
-writeLines obj buf bf@(I# bufLen) (I# initPos#) s =
+writeLines obj buf bufLen initPos s =
+ let
+ shoveString :: Int -> [Char] -> IO ()
+ shoveString n ls =
+ case ls of
+ [] ->
+ if n == 0 then
+ CCALL(setBufWPtr) obj (0::Int)
+ else do
+ {-
+ At the end of a buffer write, update the buffer position
+ in the underlying file object, so that if the handle
+ is subsequently dropped by the program, the whole
+ buffer will be properly flushed.
+
+ There's one case where this delayed up-date of the buffer
+ position can go wrong: if a thread is killed, it might be
+ in the middle of filling up a buffer, with the result that
+ the partial buffer update is lost upon finalisation. Not
+ that killing of threads is supported at the moment.
+
+ -}
+ CCALL(setBufWPtr) obj n
+
+ (x:xs) -> do
+ primWriteCharOffAddr buf n x
+ {- Flushing on buffer exhaustion or newlines (even if it isn't the last one) -}
+ if n == bufLen || x == '\n'
+ then do
+ rc <- mayBlock obj (CCALL(writeFileObject) obj (n + 1)) -- ConcHask: UNSAFE, may block.
+ if rc == 0
+ then shoveString 0 xs
+ else constructErrorAndFail "writeLines"
+ else
+ shoveString (n + 1) xs
+ in
+ shoveString initPos s
+#else /* ndef __HUGS__ */
+#ifndef __PARALLEL_HASKELL__
+writeLines :: ForeignObj -> Addr -> Int -> Int -> String -> IO ()
+#else
+writeLines :: Addr -> Addr -> Int -> Int -> String -> IO ()
+#endif
+writeLines obj buf (I# bufLen) (I# initPos#) s =
let
write_char :: Addr -> Int# -> Char# -> IO ()
- write_char (A# buf) n# c# =
+ write_char (A# buf#) n# c# =
IO $ \ s# ->
- case (writeCharOffAddr# buf n# c# s#) of s2# -> IOok s2# ()
+ case (writeCharOffAddr# buf# n# c# s#) of s2# -> (# s2#, () #)
shoveString :: Int# -> [Char] -> IO ()
shoveString n ls =
case ls of
[] ->
if n ==# 0# then
- _ccall_ setBufWPtr obj (0::Int)
+ CCALL(setBufWPtr) obj (0::Int)
else do
{-
At the end of a buffer write, update the buffer position
that killing of threads is supported at the moment.
-}
- _ccall_ setBufWPtr obj (I# n)
+ CCALL(setBufWPtr) obj (I# n)
((C# x):xs) -> do
write_char buf n x
{- Flushing on buffer exhaustion or newlines (even if it isn't the last one) -}
if n ==# bufLen || x `eqChar#` '\n'#
then do
- rc <- mayBlock obj (_ccall_ writeFileObject obj (I# (n +# 1#))) -- ConcHask: UNSAFE, may block.
+ rc <- mayBlock obj (CCALL(writeFileObject) obj (I# (n +# 1#))) -- ConcHask: UNSAFE, may block.
if rc == 0
then shoveString 0# xs
else constructErrorAndFail "writeLines"
shoveString (n +# 1#) xs
in
shoveString initPos# s
+#endif /* ndef __HUGS__ */
+
+#ifdef __HUGS__
+#ifndef __PARALLEL_HASKELL__
+writeBlocks :: ForeignObj -> Addr -> Int -> Int -> String -> IO ()
+#else
+writeBlocks :: Addr -> Addr -> Int -> Int -> String -> IO ()
+#endif
+writeBlocks obj buf bufLen initPos s =
+ let
+ shoveString :: Int -> [Char] -> IO ()
+ shoveString n ls =
+ case ls of
+ [] ->
+ if n == 0 then
+ CCALL(setBufWPtr) obj (0::Int)
+ else do
+ {-
+ At the end of a buffer write, update the buffer position
+ in the underlying file object, so that if the handle
+ is subsequently dropped by the program, the whole
+ buffer will be properly flushed.
+
+ There's one case where this delayed up-date of the buffer
+ position can go wrong: if a thread is killed, it might be
+ in the middle of filling up a buffer, with the result that
+ the partial buffer update is lost upon finalisation. However,
+ by the time killThread is supported, Haskell finalisers are also
+ likely to be in, which means the 'IOFileObject' hack can go
+ alltogether.
+
+ -}
+ CCALL(setBufWPtr) obj n
+ (x:xs) -> do
+ primWriteCharOffAddr buf n x
+ if n == bufLen
+ then do
+ rc <- mayBlock obj (CCALL(writeFileObject) obj (n + 1)) -- ConcHask: UNSAFE, may block.
+ if rc == 0
+ then shoveString 0 xs
+ else constructErrorAndFail "writeChunks"
+ else
+ shoveString (n + 1) xs
+ in
+ shoveString initPos s
+#else /* ndef __HUGS__ */
#ifndef __PARALLEL_HASKELL__
writeBlocks :: ForeignObj -> Addr -> Int -> Int -> String -> IO ()
#else
writeBlocks :: Addr -> Addr -> Int -> Int -> String -> IO ()
#endif
-writeBlocks obj buf bf@(I# bufLen) (I# initPos#) s =
+writeBlocks obj buf (I# bufLen) (I# initPos#) s =
let
write_char :: Addr -> Int# -> Char# -> IO ()
- write_char (A# buf) n# c# =
+ write_char (A# buf#) n# c# =
IO $ \ s# ->
- case (writeCharOffAddr# buf n# c# s#) of s2# -> IOok s2# ()
+ case (writeCharOffAddr# buf# n# c# s#) of s2# -> (# s2#, () #)
shoveString :: Int# -> [Char] -> IO ()
shoveString n ls =
case ls of
[] ->
if n ==# 0# then
- _ccall_ setBufWPtr obj (0::Int)
+ CCALL(setBufWPtr) obj (0::Int)
else do
{-
At the end of a buffer write, update the buffer position
alltogether.
-}
- _ccall_ setBufWPtr obj (I# n)
+ CCALL(setBufWPtr) obj (I# n)
((C# x):xs) -> do
write_char buf n x
if n ==# bufLen
then do
- rc <- mayBlock obj (_ccall_ writeFileObject obj (I# (n +# 1#))) -- ConcHask: UNSAFE, may block.
+ rc <- mayBlock obj (CCALL(writeFileObject) obj (I# (n +# 1#))) -- ConcHask: UNSAFE, may block.
if rc == 0
then shoveString 0# xs
else constructErrorAndFail "writeChunks"
shoveString (n +# 1#) xs
in
shoveString initPos# s
+#endif /* ndef __HUGS__ */
#ifndef __PARALLEL_HASKELL__
writeChars :: ForeignObj -> String -> IO ()
#else
writeChars :: Addr -> String -> IO ()
#endif
-writeChars fo "" = return ()
+writeChars _fo "" = return ()
writeChars fo (c:cs) = do
- rc <- mayBlock fo (_ccall_ filePutc fo c) -- ConcHask: UNSAFE, may block.
+ rc <- mayBlock fo (CCALL(filePutc) fo c) -- ConcHask: UNSAFE, may block.
if rc == 0
then writeChars fo cs
else constructErrorAndFail "writeChars"
\begin{code}
hPrint :: Show a => Handle -> a -> IO ()
-hPrint hdl = hPutStr hdl . show
+hPrint hdl = hPutStrLn hdl . show
\end{code}
Derived action @hPutStrLn hdl str@ writes the string \tr{str} to
after x
case rs of
Right r -> return r
- Left e -> fail e
+ Left e -> ioError e
-- variant of the above where middle computation doesn't want x
bracket_ :: IO a -> (a -> IO b) -> IO c -> IO c
after x
case rs of
Right r -> return r
- Left e -> fail e
+ Left e -> ioError e
\end{code}
%*********************************************************
readLn = do l <- getLine
r <- readIO l
return r
+
+#endif /* ndef HEAD */
+
\end{code}
projects / ghc-hetmet.git / blobdiff