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.
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