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Foreign.Marshal.Utils

Portability | portable
Stability | provisional
Maintainer | ffi@haskell.org

Contents

General marshalling utilities
  Combined allocation and marshalling
  Marshalling of Boolean values (non-zero corresponds to `True`)
  Marshalling of Maybe values
  Marshalling lists of storable objects
  Haskellish interface to memcpy and memmove
  DEPRECATED FUNCTIONS (don't use; they may disappear at any time)

Description
Utilities for primitive marshaling
Synopsis

with :: Storable a => a -> (Ptr a -> IO b) -> IO b
new :: Storable a => a -> IO (Ptr a)
fromBool :: Num a => Bool -> a
toBool :: Num a => a -> Bool
maybeNew :: (a -> IO (Ptr a)) -> Maybe a -> IO (Ptr a)
maybeWith :: (a -> (Ptr b -> IO c) -> IO c) -> Maybe a -> (Ptr b -> IO c) -> IO c
maybePeek :: (Ptr a -> IO b) -> Ptr a -> IO (Maybe b)
withMany :: (a -> (b -> res) -> res) -> [a] -> ([b] -> res) -> res
copyBytes :: Ptr a -> Ptr a -> Int -> IO ()
moveBytes :: Ptr a -> Ptr a -> Int -> IO ()
withObject :: Storable a => a -> (Ptr a -> IO b) -> IO b

General marshalling utilities
Combined allocation and marshalling
with :: Storable a => a -> (Ptr a -> IO b) -> IO b

Allocate temporary storage for a value and marshal it into this storage

- see the life time constraints imposed by `alloca`

new :: Storable a => a -> IO (Ptr a)
Allocate storage for a value and marshal it into this storage
Marshalling of Boolean values (non-zero corresponds to `True`)
fromBool :: Num a => Bool -> a
Convert a Haskell `Bool` to its numeric representation
toBool :: Num a => a -> Bool
Convert a Boolean in numeric representation to a Haskell value
Marshalling of Maybe values
maybeNew :: (a -> IO (Ptr a)) -> Maybe a -> IO (Ptr a)

Allocate storage and marshall a storable value wrapped into a `Maybe`

- the `nullPtr` is used to represent `Nothing`

maybeWith :: (a -> (Ptr b -> IO c) -> IO c) -> Maybe a -> (Ptr b -> IO c) -> IO c
Converts a `withXXX` combinator into one marshalling a value wrapped into a `Maybe`
maybePeek :: (Ptr a -> IO b) -> Ptr a -> IO (Maybe b)
Convert a peek combinator into a one returning `Nothing` if applied to a `nullPtr`
Marshalling lists of storable objects
withMany :: (a -> (b -> res) -> res) -> [a] -> ([b] -> res) -> res
Replicates a `withXXX` combinator over a list of objects, yielding a list of marshalled objects
Haskellish interface to memcpy and memmove
(argument order: destination, source)
copyBytes :: Ptr a -> Ptr a -> Int -> IO ()
Copies the given number of bytes from the second area (source) into the first (destination); the copied areas may not overlap
moveBytes :: Ptr a -> Ptr a -> Int -> IO ()
Copies the given number of elements from the second area (source) into the first (destination); the copied areas may overlap
DEPRECATED FUNCTIONS (don't use; they may disappear at any time)
withObject :: Storable a => a -> (Ptr a -> IO b) -> IO b
Produced by Haddock version 0.6