On Jul 9, 2009, at 2:58 PM, Hernan Wilkinson wrote:
So, Stef, what do we do? :-) I think we have discussed very interesting things is this thread. My conclusions are:
1) Nicolas made a change to avoid confusion when comparing "exact numbers" with "inexact numbers" (among others) 2) This change surprised some people (me in the first place) because it is not how other Smalltalks behave, it is a change in the philosophy of Smalltalk and thus it logically generates disagreements
I do not think that this is a change in philosophy. Clearly you cannot hide the limited nature of float compare to their intellectual/math counterpart.
3) It is clear that Floats are needed due to performance issues, and it is also clear that when performance is not a problem Smalltalk numbers should behave as close as possible (if not equal to) arithmetic.
So, I devise these paths: 1) Leave things as they are now in the latest Pharo image, and wait to see if Nicola's change affects real applications (not just tests as it was my case) 2) Same as 1 but making float equals work only when comparing between floats
Why not. I would like to have a consistent behavior: not true if this is 0.5 and false in 0.3
3) Change the Number hierarchy and make a clear distinction between exact numbers and inexact numbers. Make exact numbers behave as one expects in real math 4) Go back to how things were
yeap
I think they are pretty much the options... My vote goes for 1 right now. To make 2 we need to experiment more and see how it behaves. I really like 3, I'd love to see that implemented in Smalltalk but doing that model is not easy, it will take time (hey, you have a research track there!), and 4 does not make sense after Nicolas explanations
We learned all something today :) So this is a positive experience.
Bye, Hernan.
On Thu, Jul 9, 2009 at 6:04 AM, Andres Valloud<avalloud@smalltalk.comcastbiz.net> wrote:
Stephane,
Computer float numbers are NOT math float numbers. Let us accept it.
I agree with your sentiment. At the risk of being overly precise, I'd state that computer float numbers are not our everyday decimal numbers. I'd avoid the reference to "math" because computer floating point numbers do have significant math behind them.
Andres.
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