On Sat, 25 Oct 2008, Paul L wrote:
I'm have some trouble using the ST monad, and I think
I'm confused about its use of existential type.
{-# OPTIONS -XRankNTypes #-}
import Control.Monad.ST
import Data.Array.ST
I want to implement a map function that unfold
all ST monads in a list:
mapST
Thanks very much for the explanation, I now have a better understanding.
On 10/26/08, David Menendez [EMAIL PROTECTED] wrote:
..[snipped]..
It may be helpful to rewrite the types with a more explicit notation.
For example,
runST :: (a :: *) - ((s :: *) - ST s a) - a
mapST_wrong :: (a :: *)
On Sun, Oct 26, 2008 at 8:17 AM, Paul L [EMAIL PROTECTED] wrote:
Thanks very much for the explanation, I now have a better understanding.
I'm glad I could help.
On 10/26/08, David Menendez [EMAIL PROTECTED] wrote:
..[snipped]..
It may be helpful to rewrite the types with a more explicit
Am Sonntag, 26. Oktober 2008 02:18 schrieb Paul L:
I'm have some trouble using the ST monad, and I think
I'm confused about its use of existential type.
{-# OPTIONS -XRankNTypes #-}
import Control.Monad.ST
import Data.Array.ST
I want to implement a map function that unfold
all ST
On Sat, Oct 25, 2008 at 11:55 PM, Paul L [EMAIL PROTECTED] wrote:
Tnaks for the clarification, please see my further questions below
On 10/25/08, Daniel Fischer [EMAIL PROTECTED] wrote:
Sure, (g (flip readArray 0)) :: ST s Int, or, explicitly, forall s. ST s Int,
there's nothing to restrict
