[project @ 2002-10-09 17:24:12 by malcolm]
[packages/old-time.git] / System / IO.hs
1 {-# OPTIONS -fno-implicit-prelude #-}
2 -----------------------------------------------------------------------------
3 -- |
4 -- Module : System.IO
5 -- Copyright : (c) The University of Glasgow 2001
6 -- License : BSD-style (see the file libraries/base/LICENSE)
7 --
8 -- Maintainer : libraries@haskell.org
9 -- Stability : provisional
10 -- Portability : portable
11 --
12 -- The standard IO library.
13 --
14 -----------------------------------------------------------------------------
15
16 module System.IO (
17 Handle, -- abstract, instance of: Eq, Show.
18 HandlePosn(..), -- abstract, instance of: Eq, Show.
19
20 IOMode(ReadMode,WriteMode,AppendMode,ReadWriteMode),
21 BufferMode(NoBuffering,LineBuffering,BlockBuffering),
22 SeekMode(AbsoluteSeek,RelativeSeek,SeekFromEnd),
23
24 stdin, stdout, stderr, -- :: Handle
25
26 openFile, -- :: FilePath -> IOMode -> IO Handle
27 hClose, -- :: Handle -> IO ()
28 hFileSize, -- :: Handle -> IO Integer
29 hIsEOF, -- :: Handle -> IO Bool
30 isEOF, -- :: IO Bool
31
32 hSetBuffering, -- :: Handle -> BufferMode -> IO ()
33 hGetBuffering, -- :: Handle -> IO BufferMode
34 hFlush, -- :: Handle -> IO ()
35 hGetPosn, -- :: Handle -> IO HandlePosn
36 hSetPosn, -- :: HandlePosn -> IO ()
37 hSeek, -- :: Handle -> SeekMode -> Integer -> IO ()
38 #if !defined(__NHC__)
39 hTell, -- :: Handle -> IO Integer
40 #endif
41 hWaitForInput, -- :: Handle -> Int -> IO Bool
42 hReady, -- :: Handle -> IO Bool
43 hGetChar, -- :: Handle -> IO Char
44 hGetLine, -- :: Handle -> IO [Char]
45 hLookAhead, -- :: Handle -> IO Char
46 hGetContents, -- :: Handle -> IO [Char]
47 hPutChar, -- :: Handle -> Char -> IO ()
48 hPutStr, -- :: Handle -> [Char] -> IO ()
49 hPutStrLn, -- :: Handle -> [Char] -> IO ()
50 hPrint, -- :: Show a => Handle -> a -> IO ()
51 hIsOpen, hIsClosed, -- :: Handle -> IO Bool
52 hIsReadable, hIsWritable, -- :: Handle -> IO Bool
53 hIsSeekable, -- :: Handle -> IO Bool
54
55 isAlreadyExistsError, isDoesNotExistError, -- :: IOError -> Bool
56 isAlreadyInUseError, isFullError,
57 isEOFError, isIllegalOperation,
58 isPermissionError, isUserError,
59
60 ioeGetErrorString, -- :: IOError -> String
61 ioeGetHandle, -- :: IOError -> Maybe Handle
62 ioeGetFileName, -- :: IOError -> Maybe FilePath
63
64 try, -- :: IO a -> IO (Either IOError a)
65 bracket, -- :: IO a -> (a -> IO b) -> (a -> IO c) -> IO c
66 bracket_, -- :: IO a -> (a -> IO b) -> IO c -> IO c
67
68 -- Non-standard extension (but will hopefully become standard with 1.5) is
69 -- to export the Prelude io functions via IO (in addition to exporting them
70 -- from the prelude...for now.)
71 IO, -- instance MonadFix
72 FilePath, -- :: String
73 IOError,
74 ioError, -- :: IOError -> IO a
75 userError, -- :: String -> IOError
76 catch, -- :: IO a -> (IOError -> IO a) -> IO a
77 interact, -- :: (String -> String) -> IO ()
78
79 putChar, -- :: Char -> IO ()
80 putStr, -- :: String -> IO ()
81 putStrLn, -- :: String -> IO ()
82 print, -- :: Show a => a -> IO ()
83 getChar, -- :: IO Char
84 getLine, -- :: IO String
85 getContents, -- :: IO String
86 readFile, -- :: FilePath -> IO String
87 writeFile, -- :: FilePath -> String -> IO ()
88 appendFile, -- :: FilePath -> String -> IO ()
89 readIO, -- :: Read a => String -> IO a
90 readLn, -- :: Read a => IO a
91
92 #if !defined(__HUGS__) && !defined(__NHC__)
93 hPutBuf, -- :: Handle -> Ptr a -> Int -> IO ()
94 hGetBuf, -- :: Handle -> Ptr a -> Int -> IO Int
95 #endif
96
97 fixIO, -- :: (a -> IO a) -> IO a
98
99 #if !defined(__HUGS__) && !defined(__NHC__)
100 hSetEcho, -- :: Handle -> Bool -> IO ()
101 hGetEcho, -- :: Handle -> IO Bool
102
103 hIsTerminalDevice, -- :: Handle -> IO Bool
104 #endif
105 ) where
106
107 #ifdef __GLASGOW_HASKELL__
108 import GHC.Base
109 import GHC.IOBase -- Together these four Prelude modules define
110 import GHC.Handle -- all the stuff exported by IO for the GHC version
111 import GHC.IO
112 import GHC.ST ( fixST )
113 import GHC.Exception
114 import GHC.Num
115 import GHC.Read
116 import GHC.Show
117 #endif
118
119 #ifdef __HUGS__
120 import Hugs.IO
121 import Hugs.IOExts
122 #endif
123
124 #ifdef __NHC__
125 import IO
126 ( Handle ()
127 , HandlePosn ()
128 , IOMode (ReadMode,WriteMode,AppendMode,ReadWriteMode)
129 , BufferMode (NoBuffering,LineBuffering,BlockBuffering)
130 , SeekMode (AbsoluteSeek,RelativeSeek,SeekFromEnd)
131 , stdin, stdout, stderr
132 , openFile -- :: FilePath -> IOMode -> IO Handle
133 , hClose -- :: Handle -> IO ()
134 , hFileSize -- :: Handle -> IO Integer
135 , hIsEOF -- :: Handle -> IO Bool
136 , isEOF -- :: IO Bool
137 , hSetBuffering -- :: Handle -> BufferMode -> IO ()
138 , hGetBuffering -- :: Handle -> IO BufferMode
139 , hFlush -- :: Handle -> IO ()
140 , hGetPosn -- :: Handle -> IO HandlePosn
141 , hSetPosn -- :: HandlePosn -> IO ()
142 , hSeek -- :: Handle -> SeekMode -> Integer -> IO ()
143 , hWaitForInput -- :: Handle -> Int -> IO Bool
144 , hGetChar -- :: Handle -> IO Char
145 , hGetLine -- :: Handle -> IO [Char]
146 , hLookAhead -- :: Handle -> IO Char
147 , hGetContents -- :: Handle -> IO [Char]
148 , hPutChar -- :: Handle -> Char -> IO ()
149 , hPutStr -- :: Handle -> [Char] -> IO ()
150 , hIsOpen, hIsClosed -- :: Handle -> IO Bool
151 , hIsReadable, hIsWritable -- :: Handle -> IO Bool
152 , hIsSeekable -- :: Handle -> IO Bool
153 , isAlreadyExistsError, isDoesNotExistError -- :: IOError -> Bool
154 , isAlreadyInUseError, isFullError
155 , isEOFError, isIllegalOperation
156 , isPermissionError, isUserError
157 , ioeGetErrorString -- :: IOError -> String
158 , ioeGetHandle -- :: IOError -> Maybe Handle
159 , ioeGetFileName -- :: IOError -> Maybe FilePath
160 , try -- :: IO a -> IO (Either IOError a)
161 , bracket -- :: IO a -> (a -> IO b) -> (a -> IO c) -> IO c
162 , bracket_ -- :: IO a -> (a -> IO b) -> IO c -> IO c
163
164 , IO ()
165 , FilePath -- :: String
166 , IOError
167 , ioError -- :: IOError -> IO a
168 , userError -- :: String -> IOError
169 , catch -- :: IO a -> (IOError -> IO a) -> IO a
170 )
171 import NHC.Internal (unsafePerformIO)
172 #endif
173
174 import System.IO.Error
175
176 -- -----------------------------------------------------------------------------
177 -- Standard IO
178
179 #ifndef __HUGS__
180 putChar :: Char -> IO ()
181 putChar c = hPutChar stdout c
182
183 putStr :: String -> IO ()
184 putStr s = hPutStr stdout s
185
186 putStrLn :: String -> IO ()
187 putStrLn s = do putStr s
188 putChar '\n'
189
190 print :: Show a => a -> IO ()
191 print x = putStrLn (show x)
192
193 getChar :: IO Char
194 getChar = hGetChar stdin
195
196 getLine :: IO String
197 getLine = hGetLine stdin
198
199 getContents :: IO String
200 getContents = hGetContents stdin
201
202 interact :: (String -> String) -> IO ()
203 interact f = do s <- getContents
204 putStr (f s)
205
206 readFile :: FilePath -> IO String
207 readFile name = openFile name ReadMode >>= hGetContents
208
209 writeFile :: FilePath -> String -> IO ()
210 writeFile name str = do
211 hdl <- openFile name WriteMode
212 hPutStr hdl str
213 hClose hdl
214
215 appendFile :: FilePath -> String -> IO ()
216 appendFile name str = do
217 hdl <- openFile name AppendMode
218 hPutStr hdl str
219 hClose hdl
220
221 readLn :: Read a => IO a
222 readLn = do l <- getLine
223 r <- readIO l
224 return r
225
226 -- raises an exception instead of an error
227 readIO :: Read a => String -> IO a
228 readIO s = case (do { (x,t) <- reads s ;
229 ("","") <- lex t ;
230 return x }) of
231 [x] -> return x
232 [] -> ioError (userError "Prelude.readIO: no parse")
233 _ -> ioError (userError "Prelude.readIO: ambiguous parse")
234 #endif /* __HUGS__ */
235
236 hReady :: Handle -> IO Bool
237 hReady h = hWaitForInput h 0
238
239 hPutStrLn :: Handle -> String -> IO ()
240 hPutStrLn hndl str = do
241 hPutStr hndl str
242 hPutChar hndl '\n'
243
244 hPrint :: Show a => Handle -> a -> IO ()
245 hPrint hdl = hPutStrLn hdl . show
246
247 -- ---------------------------------------------------------------------------
248 -- fixIO
249
250 #ifdef __GLASGOW_HASKELL__
251 fixIO :: (a -> IO a) -> IO a
252 fixIO m = stToIO (fixST (ioToST . m))
253 #endif
254 #ifdef __NHC__
255 fixIO :: (a -> IO a) -> IO a
256 fixIO f = let x = unsafePerformIO (f x) in return x
257 #endif