[Haskell-cafe] heap lifetime question

[Henning Thielemann]

On Thu, 7 Aug 2008, Bulat Ziganshin wrote:

> Hello Vasili,
>
> Thursday, August 7, 2008, 9:33:32 AM, you wrote:
>
> oh, it was my mistake. alloca behavior is completely defined by it's
> generic implementation:
>
> allocaBytes      :: Int -> (Ptr a -> IO b) -> IO b
> allocaBytes size  = bracket (mallocBytes size) free
>
> although GHC implementation is much more efficient

That is, it is not a good idea to use 'allocaBytes n return' in order to
carry a pointer of an allocated piece of memory out of the inner action.