On Tue, Jul 19, 2005 at 08:16:35PM +1000, Ben Lippmeier wrote:
Bulat Ziganshin wrote:
reading GHC sources is always very interesting :) that is from GHC/Base.hs :
getTag :: a -> Int# getTag x = x `seq` dataToTag# x
! This is just what I was looking for, thankyou.
My shallowEq function is now simply:
shallowEq :: a -> a -> Bool shallowEq a b = getTag a ==# getTag b
My project is already totally reliant on GHC, and this will save me the heartache of hacking DrIFT (which I was in the process of setting up when I saw this mail) into my makefile.
Portability be damned!
Ben.
You might increase portability a bit by using import Data.Generics shallowEq :: Data a => a -> a -> Bool shallowEq x y = toConstr x == toConstr y it does introduce a dependency on Data though Groeten, Remi -- Nobody can be exactly like me. Even I have trouble doing it.