-{-# OPTIONS -fno-implicit-prelude #-}
+{-# OPTIONS_GHC -XNoImplicitPrelude #-}
-----------------------------------------------------------------------------
---
+-- |
-- Module : Foreign.Marshal.Array
-- Copyright : (c) The FFI task force 2001
--- License : BSD-style (see the file libraries/core/LICENSE)
+-- License : BSD-style (see the file libraries/base/LICENSE)
--
-- Maintainer : ffi@haskell.org
-- Stability : provisional
-- Portability : portable
--
--- $Id: Array.hs,v 1.4 2002/02/05 17:32:25 simonmar Exp $
---
-- Marshalling support: routines allocating, storing, and retrieving Haskell
-- lists that are represented as arrays in the foreign language
--
-----------------------------------------------------------------------------
module Foreign.Marshal.Array (
+ -- * Marshalling arrays
- -- allocation
+ -- ** Allocation
--
mallocArray, -- :: Storable a => Int -> IO (Ptr a)
mallocArray0, -- :: Storable a => Int -> IO (Ptr a)
reallocArray, -- :: Storable a => Ptr a -> Int -> IO (Ptr a)
reallocArray0, -- :: Storable a => Ptr a -> Int -> IO (Ptr a)
- -- marshalling
+ -- ** Marshalling
--
peekArray, -- :: Storable a => Int -> Ptr a -> IO [a]
peekArray0, -- :: (Storable a, Eq a) => a -> Ptr a -> IO [a]
pokeArray, -- :: Storable a => Ptr a -> [a] -> IO ()
pokeArray0, -- :: Storable a => a -> Ptr a -> [a] -> IO ()
- -- combined allocation and marshalling
+ -- ** Combined allocation and marshalling
--
newArray, -- :: Storable a => [a] -> IO (Ptr a)
newArray0, -- :: Storable a => a -> [a] -> IO (Ptr a)
withArray, -- :: Storable a => [a] -> (Ptr a -> IO b) -> IO b
withArray0, -- :: Storable a => a -> [a] -> (Ptr a -> IO b) -> IO b
- -- copying (argument order: destination, source)
- --
+ withArrayLen, -- :: Storable a => [a] -> (Int -> Ptr a -> IO b) -> IO b
+ withArrayLen0, -- :: Storable a => a -> [a] -> (Int -> Ptr a -> IO b) -> IO b
+
+ -- ** Copying
+
+ -- | (argument order: destination, source)
copyArray, -- :: Storable a => Ptr a -> Ptr a -> Int -> IO ()
moveArray, -- :: Storable a => Ptr a -> Ptr a -> Int -> IO ()
- -- finding the length
+ -- ** Finding the length
--
lengthArray0, -- :: (Storable a, Eq a) => a -> Ptr a -> IO Int
- -- indexing
+ -- ** Indexing
--
advancePtr, -- :: Storable a => Ptr a -> Int -> Ptr a
) where
-import Control.Monad
+import Foreign.Ptr (Ptr, plusPtr)
+import Foreign.Storable (Storable(alignment,sizeOf,peekElemOff,pokeElemOff))
+import Foreign.Marshal.Alloc (mallocBytes, allocaBytesAligned, reallocBytes)
+import Foreign.Marshal.Utils (copyBytes, moveBytes)
#ifdef __GLASGOW_HASKELL__
-import Foreign.Ptr (Ptr, plusPtr)
-import GHC.Storable (Storable(sizeOf,peekElemOff,pokeElemOff))
-import Foreign.Marshal.Alloc (mallocBytes, allocaBytes, reallocBytes)
-import Foreign.Marshal.Utils (copyBytes, moveBytes)
-import GHC.IOBase
import GHC.Num
import GHC.List
import GHC.Err
import GHC.Base
+#else
+import Control.Monad (zipWithM_)
#endif
-- allocation
-- ----------
--- allocate storage for the given number of elements of a storable type
+-- |Allocate storage for the given number of elements of a storable type
+-- (like 'Foreign.Marshal.Alloc.malloc', but for multiple elements).
--
mallocArray :: Storable a => Int -> IO (Ptr a)
mallocArray = doMalloc undefined
where
- doMalloc :: Storable a => a -> Int -> IO (Ptr a)
+ doMalloc :: Storable a' => a' -> Int -> IO (Ptr a')
doMalloc dummy size = mallocBytes (size * sizeOf dummy)
--- like `mallocArray', but add an extra element to signal the end of the array
+-- |Like 'mallocArray', but add an extra position to hold a special
+-- termination element.
--
mallocArray0 :: Storable a => Int -> IO (Ptr a)
mallocArray0 size = mallocArray (size + 1)
--- temporarily allocate space for the given number of elements
---
--- * see `MarshalAlloc.alloca' for the storage lifetime constraints
+-- |Temporarily allocate space for the given number of elements
+-- (like 'Foreign.Marshal.Alloc.alloca', but for multiple elements).
--
allocaArray :: Storable a => Int -> (Ptr a -> IO b) -> IO b
allocaArray = doAlloca undefined
where
- doAlloca :: Storable a => a -> Int -> (Ptr a -> IO b) -> IO b
- doAlloca dummy size = allocaBytes (size * sizeOf dummy)
+ doAlloca :: Storable a' => a' -> Int -> (Ptr a' -> IO b') -> IO b'
+ doAlloca dummy size = allocaBytesAligned (size * sizeOf dummy)
+ (alignment dummy)
--- like `allocaArray', but add an extra element to signal the end of the array
+-- |Like 'allocaArray', but add an extra position to hold a special
+-- termination element.
--
allocaArray0 :: Storable a => Int -> (Ptr a -> IO b) -> IO b
allocaArray0 size = allocaArray (size + 1)
+{-# INLINE allocaArray0 #-}
+ -- needed to get allocaArray to inline into withCString, for unknown
+ -- reasons --SDM 23/4/2010, see #4004 for benchmark
--- adjust the size of an array
+-- |Adjust the size of an array
--
reallocArray :: Storable a => Ptr a -> Int -> IO (Ptr a)
reallocArray = doRealloc undefined
where
- doRealloc :: Storable a => a -> Ptr a -> Int -> IO (Ptr a)
+ doRealloc :: Storable a' => a' -> Ptr a' -> Int -> IO (Ptr a')
doRealloc dummy ptr size = reallocBytes ptr (size * sizeOf dummy)
--- adjust the size of an array while adding an element for the end marker
+-- |Adjust the size of an array including an extra position for the end marker.
--
reallocArray0 :: Storable a => Ptr a -> Int -> IO (Ptr a)
reallocArray0 ptr size = reallocArray ptr (size + 1)
-- marshalling
-- -----------
--- convert an array of given length into a Haskell list. This version
--- traverses the array backwards using an accumulating parameter,
--- which uses constant stack space. The previous version using mapM
--- needed linear stack space.
+-- |Convert an array of given length into a Haskell list. The implementation
+-- is tail-recursive and so uses constant stack space.
--
peekArray :: Storable a => Int -> Ptr a -> IO [a]
peekArray size ptr | size <= 0 = return []
f 0 acc = do e <- peekElemOff ptr 0; return (e:acc)
f n acc = do e <- peekElemOff ptr n; f (n-1) (e:acc)
--- convert an array terminated by the given end marker into a Haskell list
+-- |Convert an array terminated by the given end marker into a Haskell list
--
peekArray0 :: (Storable a, Eq a) => a -> Ptr a -> IO [a]
-peekArray0 marker ptr = loop 0
- where
- loop i = do
- val <- peekElemOff ptr i
- if val == marker then return [] else do
- rest <- loop (i+1)
- return (val:rest)
+peekArray0 marker ptr = do
+ size <- lengthArray0 marker ptr
+ peekArray size ptr
--- write the list elements consecutive into memory
+-- |Write the list elements consecutive into memory
--
-pokeArray :: Storable a => Ptr a -> [a] -> IO ()
-pokeArray ptr vals = zipWithM_ (pokeElemOff ptr) [0..] vals
+pokeArray :: Storable a => Ptr a -> [a] -> IO ()
+#ifndef __GLASGOW_HASKELL__
+pokeArray ptr vals = zipWithM_ (pokeElemOff ptr) [0..] vals
+#else
+pokeArray ptr vals0 = go vals0 0#
+ where go [] _ = return ()
+ go (val:vals) n# = do pokeElemOff ptr (I# n#) val; go vals (n# +# 1#)
+#endif
--- write the list elements consecutive into memory and terminate them with the
+-- |Write the list elements consecutive into memory and terminate them with the
-- given marker element
--
-pokeArray0 :: Storable a => a -> Ptr a -> [a] -> IO ()
+pokeArray0 :: Storable a => a -> Ptr a -> [a] -> IO ()
+#ifndef __GLASGOW_HASKELL__
pokeArray0 marker ptr vals = do
pokeArray ptr vals
pokeElemOff ptr (length vals) marker
+#else
+pokeArray0 marker ptr vals0 = go vals0 0#
+ where go [] n# = pokeElemOff ptr (I# n#) marker
+ go (val:vals) n# = do pokeElemOff ptr (I# n#) val; go vals (n# +# 1#)
+#endif
-- combined allocation and marshalling
-- -----------------------------------
--- write a list of storable elements into a newly allocated, consecutive
+-- |Write a list of storable elements into a newly allocated, consecutive
-- sequence of storable values
+-- (like 'Foreign.Marshal.Utils.new', but for multiple elements).
--
newArray :: Storable a => [a] -> IO (Ptr a)
newArray vals = do
pokeArray ptr vals
return ptr
--- write a list of storable elements into a newly allocated, consecutive
+-- |Write a list of storable elements into a newly allocated, consecutive
-- sequence of storable values, where the end is fixed by the given end marker
--
newArray0 :: Storable a => a -> [a] -> IO (Ptr a)
pokeArray0 marker ptr vals
return ptr
--- temporarily store a list of storable values in memory
+-- |Temporarily store a list of storable values in memory
+-- (like 'Foreign.Marshal.Utils.with', but for multiple elements).
--
-withArray :: Storable a => [a] -> (Ptr a -> IO b) -> IO b
-withArray vals f =
+withArray :: Storable a => [a] -> (Ptr a -> IO b) -> IO b
+withArray vals = withArrayLen vals . const
+
+-- |Like 'withArray', but the action gets the number of values
+-- as an additional parameter
+--
+withArrayLen :: Storable a => [a] -> (Int -> Ptr a -> IO b) -> IO b
+withArrayLen vals f =
allocaArray len $ \ptr -> do
pokeArray ptr vals
- res <- f ptr
+ res <- f len ptr
return res
where
len = length vals
--- like `withArray', but a terminator indicates where the array ends
+-- |Like 'withArray', but a terminator indicates where the array ends
+--
+withArray0 :: Storable a => a -> [a] -> (Ptr a -> IO b) -> IO b
+withArray0 marker vals = withArrayLen0 marker vals . const
+
+-- |Like 'withArrayLen', but a terminator indicates where the array ends
--
-withArray0 :: Storable a => a -> [a] -> (Ptr a -> IO b) -> IO b
-withArray0 marker vals f =
+withArrayLen0 :: Storable a => a -> [a] -> (Int -> Ptr a -> IO b) -> IO b
+withArrayLen0 marker vals f =
allocaArray0 len $ \ptr -> do
pokeArray0 marker ptr vals
- res <- f ptr
+ res <- f len ptr
return res
where
len = length vals
-- copying (argument order: destination, source)
-- -------
--- copy the given number of elements from the second array (source) into the
--- first array (destination); the copied areas may *not* overlap
+-- |Copy the given number of elements from the second array (source) into the
+-- first array (destination); the copied areas may /not/ overlap
--
copyArray :: Storable a => Ptr a -> Ptr a -> Int -> IO ()
copyArray = doCopy undefined
where
- doCopy :: Storable a => a -> Ptr a -> Ptr a -> Int -> IO ()
+ doCopy :: Storable a' => a' -> Ptr a' -> Ptr a' -> Int -> IO ()
doCopy dummy dest src size = copyBytes dest src (size * sizeOf dummy)
--- copy the given number of elements from the second array (source) into the
--- first array (destination); the copied areas *may* overlap
+-- |Copy the given number of elements from the second array (source) into the
+-- first array (destination); the copied areas /may/ overlap
--
moveArray :: Storable a => Ptr a -> Ptr a -> Int -> IO ()
moveArray = doMove undefined
where
- doMove :: Storable a => a -> Ptr a -> Ptr a -> Int -> IO ()
+ doMove :: Storable a' => a' -> Ptr a' -> Ptr a' -> Int -> IO ()
doMove dummy dest src size = moveBytes dest src (size * sizeOf dummy)
-- finding the length
-- ------------------
--- return the number of elements in an array, excluding the terminator
+-- |Return the number of elements in an array, excluding the terminator
--
lengthArray0 :: (Storable a, Eq a) => a -> Ptr a -> IO Int
lengthArray0 marker ptr = loop 0
-- indexing
-- --------
--- advance a pointer into an array by the given number of elements
+-- |Advance a pointer into an array by the given number of elements
--
advancePtr :: Storable a => Ptr a -> Int -> Ptr a
advancePtr = doAdvance undefined
where
- doAdvance :: Storable a => a -> Ptr a -> Int -> Ptr a
+ doAdvance :: Storable a' => a' -> Ptr a' -> Int -> Ptr a'
doAdvance dummy ptr i = ptr `plusPtr` (i * sizeOf dummy)
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