System.IO.ExplicitIOModes

explicit-iomodes-0.1: File handles with explicit IOModes

System.IO.ExplicitIOModes

Maintainer

Bas van Dijk <v.dijk.bas@gmail.com>

Description

This module exports a Handle to a file which is parameterized with the IOMode the handle is in. All operations on handles explicitly specify the needed IOMode. This way it is impossible to read from a write-only handle or write to a read-only handle for example.

This modules re-exports everything from System.IO so you can just replace: import System.IO with: import System.IO.ExplicitIOModes, change some type signatures and expect everything to type-check.

There's one exception to this last statement: If you are using the standard handles stdin, stdout or stderr in a mode which isn't their default mode (R for stdin and W for stdout and stderr) you have to cast these handles to the expected IOMode.

Synopsis

IO (IO)

data Handle ioMode

data R

data W

data A

data RW

stdin :: Handle R

stdout :: Handle W

stderr :: Handle W

cast :: forall anyIOMode castedIOMode. CheckMode castedIOMode => Handle anyIOMode -> IO (Maybe (Handle castedIOMode))

withFile :: FilePath -> IOMode ioMode -> (Handle ioMode -> IO r) -> IO r

openFile :: FilePath -> IOMode ioMode -> IO (Handle ioMode)

data IOMode ioMode where

ReadMode :: IOMode R

WriteMode :: IOMode W

AppendMode :: IOMode A

ReadWriteMode :: IOMode RW

hClose :: Handle ioMode -> IO ()

hFileSize :: Handle ioMode -> IO Integer

hSetFileSize :: Handle ioMode -> Integer -> IO ()

hIsEOF :: ReadModes ioMode => Handle ioMode -> IO Bool

BufferMode (NoBuffering, LineBuffering, BlockBuffering)

hSetBuffering :: Handle ioMode -> BufferMode -> IO ()

hGetBuffering :: Handle ioMode -> IO BufferMode

hFlush :: Handle ioMode -> IO ()

hGetPosn :: Handle ioMode -> IO HandlePosn

HandlePosn (HandlePosn)

hSeek :: Handle ioMode -> SeekMode -> Integer -> IO ()

SeekMode (AbsoluteSeek, RelativeSeek, SeekFromEnd)

hTell :: Handle ioMode -> IO Integer

hIsOpen :: Handle ioMode -> IO Bool

hIsClosed :: Handle ioMode -> IO Bool

hIsReadable :: Handle ioMode -> IO Bool

hIsWritable :: Handle ioMode -> IO Bool

hIsSeekable :: Handle ioMode -> IO Bool

hIsTerminalDevice :: Handle ioMode -> IO Bool

hSetEcho :: Handle ioMode -> Bool -> IO ()

hGetEcho :: Handle ioMode -> IO Bool

hShow :: Handle ioMode -> IO String

hWaitForInput :: ReadModes ioMode => Handle ioMode -> Int -> IO Bool

hReady :: ReadModes ioMode => Handle ioMode -> IO Bool

hGetChar :: ReadModes ioMode => Handle ioMode -> IO Char

hGetLine :: ReadModes ioMode => Handle ioMode -> IO String

hLookAhead :: ReadModes ioMode => Handle ioMode -> IO Char

hGetContents :: ReadModes ioMode => Handle ioMode -> IO String

hPutChar :: WriteModes ioMode => Handle ioMode -> Char -> IO ()

hPutStr :: WriteModes ioMode => Handle ioMode -> String -> IO ()

hPutStrLn :: WriteModes ioMode => Handle ioMode -> String -> IO ()

hPrint :: (WriteModes ioMode, Show a) => Handle ioMode -> a -> IO ()

withBinaryFile :: FilePath -> IOMode ioMode -> (Handle ioMode -> IO r) -> IO r

openBinaryFile :: FilePath -> IOMode ioMode -> IO (Handle ioMode)

hSetBinaryMode :: Handle ioMode -> Bool -> IO ()

hPutBuf :: WriteModes ioMode => Handle ioMode -> Ptr a -> Int -> IO ()

hGetBuf :: ReadModes ioMode => Handle ioMode -> Ptr a -> Int -> IO Int

hPutBufNonBlocking :: WriteModes ioMode => Handle ioMode -> Ptr a -> Int -> IO Int

hGetBufNonBlocking :: ReadModes ioMode => Handle ioMode -> Ptr a -> Int -> IO Int

openTempFile :: FilePath -> String -> IO (FilePath, Handle RW)

openBinaryTempFile :: FilePath -> String -> IO (FilePath, Handle RW)

IO (IO)

Files and handles

data Handle ioMode

A handle to a file with an explicit IOMode.

Wraps: System.IO.Handle.

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Instances

Typeable1 Handle

Eq (Handle ioMode)

Show (Handle ioMode)

Types that represent the IOMode a Handle can be in.

data R

Read only.

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Instances

CheckMode R

ReadModes R

data W

Write only.

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Instances

CheckMode W

WriteModes W

data A

Append.

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Instances

CheckMode A

WriteModes A

data RW

Read and write.

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Instances

CheckMode RW

WriteModes RW

ReadModes RW

Standard handles

These standard handles have concrete IOModes by default which work for the majority of cases. In the rare occasion that you know these handles have different IOModes you can cast them.

stdin :: Handle R

Wraps: System.IO.stdin.

stdout :: Handle W

Wraps: System.IO.stdout.

stderr :: Handle W

Wraps: System.IO.stderr.

cast :: forall anyIOMode castedIOMode. CheckMode castedIOMode => Handle anyIOMode -> IO (Maybe (Handle castedIOMode))

Cast the IOMode of a handle if the handle supports it.

Opening and closing files

withFile :: FilePath -> IOMode ioMode -> (Handle ioMode -> IO r) -> IO r

Wraps: System.IO.withFile.

openFile :: FilePath -> IOMode ioMode -> IO (Handle ioMode)

Wraps: System.IO.openFile.

data IOMode ioMode where

The IOMode GADT which for each constructor specifies the associated IOMode type.

Also see: System.IO.IOMode.

Constructors

ReadMode :: IOMode R
WriteMode :: IOMode W
AppendMode :: IOMode A
ReadWriteMode :: IOMode RW

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Instances

Eq (IOMode ioMode)

Ord (IOMode ioMode)

Show (IOMode ioMode)

hClose :: Handle ioMode -> IO ()

Wraps: System.IO.hClose.

Operations on handles

Determining and changing the size of a file

hFileSize :: Handle ioMode -> IO Integer

Wraps: System.IO.hFileSize.

hSetFileSize :: Handle ioMode -> Integer -> IO ()

Wraps: System.IO.hSetFileSize.

Detecting the end of input

hIsEOF :: ReadModes ioMode => Handle ioMode -> IO Bool

Wraps: System.IO.hIsEOF.

Buffering operations

BufferMode (NoBuffering, LineBuffering, BlockBuffering)

hSetBuffering :: Handle ioMode -> BufferMode -> IO ()

Wraps: System.IO.hSetBuffering.

hGetBuffering :: Handle ioMode -> IO BufferMode

Wraps: System.IO.hGetBuffering.

hFlush :: Handle ioMode -> IO ()

Wraps: System.IO.hFlush.

Repositioning handles

hGetPosn :: Handle ioMode -> IO HandlePosn

Wraps: System.IO.hGetPosn.

HandlePosn (HandlePosn)

hSeek :: Handle ioMode -> SeekMode -> Integer -> IO ()

Wraps: System.IO.hSeek.

SeekMode (AbsoluteSeek, RelativeSeek, SeekFromEnd)

hTell :: Handle ioMode -> IO Integer

Wraps: System.IO.hTell.

Handle properties

hIsOpen :: Handle ioMode -> IO Bool

Wraps: System.IO.hIsOpen.

hIsClosed :: Handle ioMode -> IO Bool

Wraps: System.IO.hIsClosed.

hIsReadable :: Handle ioMode -> IO Bool

Wraps: System.IO.hIsReadable.

hIsWritable :: Handle ioMode -> IO Bool

Wraps: System.IO.hIsWritable.

hIsSeekable :: Handle ioMode -> IO Bool

Wraps: System.IO.hIsSeekable.

Terminal operations (not portable: GHC/Hugs only)

hIsTerminalDevice :: Handle ioMode -> IO Bool

Wraps: System.IO.hIsTerminalDevice.

hSetEcho :: Handle ioMode -> Bool -> IO ()

Wraps: System.IO.hSetEcho.

hGetEcho :: Handle ioMode -> IO Bool

Wraps: System.IO.hGetEcho.

Showing handle state (not portable: GHC only)

hShow :: Handle ioMode -> IO String

Wraps: System.IO.hShow.

Text input and output

Note that the following text input operations are polymorphic in the IOMode of the given handle. However the IOModes are restricted to ReadModes only which can be either R or RW.

hWaitForInput :: ReadModes ioMode => Handle ioMode -> Int -> IO Bool

Wraps: System.IO.hWaitForInput.

hReady :: ReadModes ioMode => Handle ioMode -> IO Bool

Wraps: System.IO.hReady.

hGetChar :: ReadModes ioMode => Handle ioMode -> IO Char

Wraps: System.IO.hGetChar.

hGetLine :: ReadModes ioMode => Handle ioMode -> IO String

Wraps: System.IO.hGetLine.

hLookAhead :: ReadModes ioMode => Handle ioMode -> IO Char

Wraps: System.IO.hLookAhead.

hGetContents :: ReadModes ioMode => Handle ioMode -> IO String

Wraps: System.IO.hGetContents.

Note that the following text output operations are polymorphic in the IOMode of the given handle. However the IOModes are restricted to WriteModes only which can be either W, A or RW.

hPutChar :: WriteModes ioMode => Handle ioMode -> Char -> IO ()

Wraps: System.IO.hPutChar.

hPutStr :: WriteModes ioMode => Handle ioMode -> String -> IO ()

Wraps: System.IO.hPutStr.

hPutStrLn :: WriteModes ioMode => Handle ioMode -> String -> IO ()

Wraps: System.IO.hPutStrLn.

hPrint :: (WriteModes ioMode, Show a) => Handle ioMode -> a -> IO ()

Wraps: System.IO.hPrint.

Special cases for standard input and output

These functions are also exported by the Prelude.

Binary input and output

withBinaryFile :: FilePath -> IOMode ioMode -> (Handle ioMode -> IO r) -> IO r

Wraps: System.IO.withBinaryFile.

openBinaryFile :: FilePath -> IOMode ioMode -> IO (Handle ioMode)

Wraps: System.IO.openBinaryFile.

hSetBinaryMode :: Handle ioMode -> Bool -> IO ()

Wraps: System.IO.hSetBinaryMode.

hPutBuf :: WriteModes ioMode => Handle ioMode -> Ptr a -> Int -> IO ()

Wraps: System.IO.hPutBuf.

hGetBuf :: ReadModes ioMode => Handle ioMode -> Ptr a -> Int -> IO Int

Wraps: System.IO.hGetBuf.

hPutBufNonBlocking :: WriteModes ioMode => Handle ioMode -> Ptr a -> Int -> IO Int

Wraps: System.IO.hPutBufNonBlocking.

hGetBufNonBlocking :: ReadModes ioMode => Handle ioMode -> Ptr a -> Int -> IO Int

Wraps: System.IO.hGetBufNonBlocking.

Temporary files

openTempFile :: FilePath -> String -> IO (FilePath, Handle RW)

Wraps: System.IO.openTempFile.

openBinaryTempFile :: FilePath -> String -> IO (FilePath, Handle RW)

Wraps: System.IO.openBinaryTempFile.

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