On 14 October 2011 14:01, Ertugrul Soeylemez wrote:

Is there any particular reason to prefer storable vectors instead of unboxed vectors?  The element type is fixed to Word8 anyway.

To be able to safely interface with foreign libraries. Note that unboxed vectors are represented as ByteArray#s. These are "unpinned" which means that the GC can freely move them through the heap to defragment your memory. If a foreign library had a pointer to an unboxed vector and the GC would move the memory to some place else, your program could crash. Storable vectors use a ForeignPtr instead which (according how you allocated it) points to "pinned" memory. You might like to follow the just created: http://hackage.haskell.org/trac/ghc/ticket/5556 which proposes the pin# and unpin# primitives for dynamically pinning and unpinning ByteArray#s. This way, as pumpkin explains it, you don't have to decide up front whether you want to suffer from memory fragmentation or to support foreign bindings. It would be really nice if that could be implemented! Bas