Re: space efficiency question

[Frank Dellaert]

Title: Message

Thanks !   Now, a small follow-up question: if I subsequently test 2 Instances whether they were instantiated with the same Attributes value, as in   test (Instance a1 _) (Instance a2 _) = (a1==a2)   will this be implemented efficiently ? I.e. will it check first whether the pointers happen to be the same, and only then do a full Eq comparison ?   Cheers Frank ----- Original Message ----- From: Simon Peyton-Jones To: Frank Dellaert ; [EMAIL PROTECTED] Sent: Monday, December 17, 2001 10:24 AM Subject: RE: space efficiency question Now: if I have a couple of thousand of these Instances, created with the same Attributes value, as in:   a = Attributes ["a","bc"] i0000 = Instance a [1,2] i0001 = Instance a [1,1] ... i7896 = Instance a [2,1]   can I be assured that there are not thousands of actual copies of a but that they simply have a pointer to a ? I'm interested in the answer for both ghc (compiled/interpreted) as interpreted Hugs.  Yes for GHC: you'll only get one copy of 'a'.   Simon