add module intro from Haskell 2010

[ghc-base.git] / Foreign / Marshal / Array.hs

diff --git a/Foreign/Marshal/Array.hs b/Foreign/Marshal/Array.hs
index fa23be9..8d8da7b 100644 (file)
--- a/Foreign/Marshal/Array.hs
+++ b/Foreign/Marshal/Array.hs
@@ -62,18 +62,18 @@ module Foreign.Marshal.Array (
   advancePtr,     -- :: Storable a => Ptr a -> Int -> Ptr a
 ) where
 
-import Control.Monad
 import Foreign.Ptr      (Ptr, plusPtr)
 import Foreign.Storable (Storable(sizeOf,peekElemOff,pokeElemOff))
 import Foreign.Marshal.Alloc (mallocBytes, allocaBytes, reallocBytes)
 import Foreign.Marshal.Utils (copyBytes, moveBytes)
 
 #ifdef __GLASGOW_HASKELL__
-import GHC.IOBase
 import GHC.Num
 import GHC.List
 import GHC.Err
 import GHC.Base
+#else
+import Control.Monad (zipWithM_)
 #endif
 
 -- allocation
@@ -108,6 +108,9 @@ allocaArray  = doAlloca undefined
 --
 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
 --
@@ -126,10 +129,8 @@ 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 []
@@ -151,8 +152,8 @@ pokeArray :: Storable a => Ptr a -> [a] -> IO ()
 #ifndef __GLASGOW_HASKELL__
 pokeArray ptr vals =  zipWithM_ (pokeElemOff ptr) [0..] vals
 #else
-pokeArray ptr vals = go vals 0#
-  where go [] n#         = return ()
+pokeArray ptr vals0 = go vals0 0#
+  where go [] _          = return ()
         go (val:vals) n# = do pokeElemOff ptr (I# n#) val; go vals (n# +# 1#)
 #endif
 
@@ -165,7 +166,7 @@ pokeArray0 marker ptr vals  = do
   pokeArray ptr vals
   pokeElemOff ptr (length vals) marker
 #else
-pokeArray0 marker ptr vals = go vals 0#
+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