Data.FilePlow

Documentation

class PlowHandle hdl where

Minimal complete definition

pSeek, pTell, pGetChar, pGetLine, pIsEOF, pFileSize

Methods

pSeek :: hdl -> SeekMode -> Integer -> IO ()

pTell :: hdl -> IO Integer

pGetChar :: hdl -> IO Char

pGetLine :: hdl -> IO ByteString

pIsEOF :: hdl -> IO Bool

pFileSize :: hdl -> IO Integer

Instances

PlowHandle Handle

Methods

pSeek :: Handle -> SeekMode -> Integer -> IO ()

pTell :: Handle -> IO Integer

pGetChar :: Handle -> IO Char

pGetLine :: Handle -> IO ByteString

pIsEOF :: Handle -> IO Bool

pFileSize :: Handle -> IO Integer

PlowHandle h => PlowHandle (MultiHandle h)

Methods

pSeek :: MultiHandle h -> SeekMode -> Integer -> IO ()

pTell :: MultiHandle h -> IO Integer

pGetChar :: MultiHandle h -> IO Char

pGetLine :: MultiHandle h -> IO ByteString

pIsEOF :: MultiHandle h -> IO Bool

pFileSize :: MultiHandle h -> IO Integer

data Handle :: *

Haskell defines operations to read and write characters from and to files, represented by values of type Handle. Each value of this type is a handle: a record used by the Haskell run-time system to manage I/O with file system objects. A handle has at least the following properties:

• whether it manages input or output or both;
• whether it is open, closed or semi-closed;
• whether the object is seekable;
• whether buffering is disabled, or enabled on a line or block basis;
• a buffer (whose length may be zero).

Most handles will also have a current I/O position indicating where the next input or output operation will occur. A handle is readable if it manages only input or both input and output; likewise, it is writable if it manages only output or both input and output. A handle is open when first allocated. Once it is closed it can no longer be used for either input or output, though an implementation cannot re-use its storage while references remain to it. Handles are in the Show and Eq classes. The string produced by showing a handle is system dependent; it should include enough information to identify the handle for debugging. A handle is equal according to == only to itself; no attempt is made to compare the internal state of different handles for equality.

Instances

Eq Handle

Methods

(==) :: Handle -> Handle -> Bool

(/=) :: Handle -> Handle -> Bool

Show Handle

Methods

showsPrec :: Int -> Handle -> ShowS

show :: Handle -> String

showList :: [Handle] -> ShowS

PlowHandle Handle

Methods

pSeek :: Handle -> SeekMode -> Integer -> IO ()

pTell :: Handle -> IO Integer

pGetChar :: Handle -> IO Char

pGetLine :: Handle -> IO ByteString

pIsEOF :: Handle -> IO Bool

pFileSize :: Handle -> IO Integer

data SeekMode :: *

A mode that determines the effect of hSeek hdl mode i.

Constructors

AbsoluteSeek

the position of hdl is set to i.

RelativeSeek

the position of hdl is set to offset i from the current position.

SeekFromEnd

the position of hdl is set to offset i from the end of the file.

Instances

Enum SeekMode

Methods

succ :: SeekMode -> SeekMode

pred :: SeekMode -> SeekMode

toEnum :: Int -> SeekMode

fromEnum :: SeekMode -> Int

enumFrom :: SeekMode -> [SeekMode]

enumFromThen :: SeekMode -> SeekMode -> [SeekMode]

enumFromTo :: SeekMode -> SeekMode -> [SeekMode]

enumFromThenTo :: SeekMode -> SeekMode -> SeekMode -> [SeekMode]

Eq SeekMode

Methods

(==) :: SeekMode -> SeekMode -> Bool

(/=) :: SeekMode -> SeekMode -> Bool

Ord SeekMode

Methods

compare :: SeekMode -> SeekMode -> Ordering

(<) :: SeekMode -> SeekMode -> Bool

(<=) :: SeekMode -> SeekMode -> Bool

(>) :: SeekMode -> SeekMode -> Bool

(>=) :: SeekMode -> SeekMode -> Bool

max :: SeekMode -> SeekMode -> SeekMode

min :: SeekMode -> SeekMode -> SeekMode

Read SeekMode

Methods

readsPrec :: Int -> ReadS SeekMode

readList :: ReadS [SeekMode]

readPrec :: ReadPrec SeekMode

readListPrec :: ReadPrec [SeekMode]

Show SeekMode

Methods

showsPrec :: Int -> SeekMode -> ShowS

show :: SeekMode -> String

showList :: [SeekMode] -> ShowS

Ix SeekMode

Methods

range :: (SeekMode, SeekMode) -> [SeekMode]

index :: (SeekMode, SeekMode) -> SeekMode -> Int

unsafeIndex :: (SeekMode, SeekMode) -> SeekMode -> Int

inRange :: (SeekMode, SeekMode) -> SeekMode -> Bool

rangeSize :: (SeekMode, SeekMode) -> Int

unsafeRangeSize :: (SeekMode, SeekMode) -> Int

seekUntil :: PlowHandle hdl => hdl -> (Char -> Bool) -> IO Bool

Seek until a certain charater is reached

seekUntilRev :: PlowHandle hdl => hdl -> (Char -> Bool) -> IO Bool

Seek until a certain charater is reached in reverse

data MultiHandle h

Instances

PlowHandle h => PlowHandle (MultiHandle h)

Methods

pSeek :: MultiHandle h -> SeekMode -> Integer -> IO ()

pTell :: MultiHandle h -> IO Integer

pGetChar :: MultiHandle h -> IO Char

pGetLine :: MultiHandle h -> IO ByteString

pIsEOF :: MultiHandle h -> IO Bool

pFileSize :: MultiHandle h -> IO Integer

withMultiHandle :: [FilePath] -> (MultiHandle Handle -> IO a) -> IO a