that is what I thought .. especially after just looking at the implementation for alloca/allocaBytes. For me and others on thie group is there documentation on the ghc run-time model and also the run-time library architecture. Both would help/aid in reading the code and of course educate more people?

Regards,

Vasili

On Thu, Aug 7, 2008 at 1:36 AM, Henning Thielemann <lemming@henning-thielemann.de> wrote:

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.