[PATCH 1/2] add calloc and callocBytes to Foreign.Marshal.Alloc

[Jason Dagit]

---
 Foreign/Marshal/Alloc.hs |   29 +++++++++++++++++++++++++++++
 1 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/Foreign/Marshal/Alloc.hs b/Foreign/Marshal/Alloc.hs
index 612d2c7..148190b 100644
--- a/Foreign/Marshal/Alloc.hs
+++ b/Foreign/Marshal/Alloc.hs
@@ -53,6 +53,9 @@ module Foreign.Marshal.Alloc (
   malloc,       -- :: Storable a =>        IO (Ptr a)
   mallocBytes,  -- ::               Int -> IO (Ptr a)
 
+  calloc,       -- :: Storable a =>        IO (Ptr a)
+  callocBytes,  -- ::               Int -> IO (Ptr a)
+
   realloc,      -- :: Storable b => Ptr a        -> IO (Ptr b)
   reallocBytes, -- ::               Ptr a -> Int -> IO (Ptr a)
 
@@ -168,6 +171,32 @@ allocaBytesAligned :: Int -> Int -> (Ptr a -> IO b) -> IO b
 allocaBytesAligned size align = allocaBytes size -- wrong
 #endif
 
+-- | Allocate a block of memory that is sufficient to hold values of type
+-- @a at .  The size of the area allocated is determined by the 'sizeOf'
+-- method from the instance of 'Storable' for the appropriate type.
+-- The memory is initalized to 0.
+--
+-- The memory may be deallocated using 'free' or 'finalizerFree' when
+-- no longer required.
+--
+{-# INLINE calloc #-}
+calloc :: Storable a => IO (Ptr a)
+calloc = doCalloc undefined
+  where
+  doCalloc       :: Storable b => b -> IO (Ptr b)
+  doCalloc dummy = callocBytes (sizeOf dummy)
+
+-- | Allocate a block of memory of the given number of bytes.
+-- The block of memory is sufficiently aligned for any of the basic
+-- foreign tyes that fit into a memory block of the allocated size.
+-- The memory is initialized to 0.
+--
+-- The memory may be deallocated using 'free' or 'finalizerFree' when
+-- no longer required.
+--
+callocBytes :: Int -> IO (Ptr a)
+callocBytes size = failWhenNULL "calloc" (_calloc (fromIntegral size) 1)
+
 -- |Resize a memory area that was allocated with 'malloc' or 'mallocBytes'
 -- to the size needed to store values of type @b at .  The returned pointer
 -- may refer to an entirely different memory area, but will be suitably
-- 
1.7.4.1