Re: [Haskell-cafe] Does GHC compare pointers when eval'ing (==)

As I understood, the question was if GHC would first compare pointers, and only call the Eq instance if the pointers are not equal. I guess this would be safe, but I don't think GHC does such a thing. Erik On Wed, Aug 20, 2014 at 9:09 AM, Alois Cochard wrote:

Hi Johan,

Haskell does not support referential equality, as that would break referential transparency.

http://stackoverflow.com/questions/1717553/pointer-equality-in-haskell

Cheers

On Aug 20, 2014 7:52 AM, "Johan Holmquist" wrote:

...

Comparing two structures for equality (structurally) can be expensive. But if their references are the same they would for sure be equal (unless (==) was defined in some funny way). Does GHC perform any such optimization?

(Likely a question for another list but I make a stab here first. )

_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe