Re: Proposal: Don't require users to use undefined

On 10/27/10 01:51, Bas van Dijk wrote:

On Tue, Oct 26, 2010 at 9:09 PM, Henning Thielemann wrote:

...

On Tue, 26 Oct 2010, Bas van Dijk wrote:

...

malloc :: forall a. Storable a => IO (Ptr a) malloc = mallocBytes (untag (sizeOf :: SizeOf a))

(Note that this does require the ScopedTypeVariables language extension.)

Haskell 98 solution would be nicer. Something like

...

malloc :: Storable a => IO (Ptr a) malloc =

let aux :: Storable a => SizeOf a -> IO (Ptr a) aux = mallocBytes . untag in aux sizeOf

Great! It's nice to know that this proposal doesn't require ScopedTypeVariables.

It may not *require* it, but the code using ScopedTypeVariables is far more readable than that Haskell98/Haskell2010 code (though, perhaps we can improve on its readability a bit). (ScopedTypeVariables is not in Haskell2010, according to http://www.haskell.org/onlinereport/haskell2010/haskellli2.html#x3-5000 ) -Isaac