On Fri, Mar 17, 2006 at 04:48:52PM +0000, Aaron Denney wrote:
Sometime back on one of the other Haskell lists, there was a proposal to not have the floating types instances of Enum and instead have some other class to which [a, b..c] desugars. That is, rename enumFromThen and friends and put them in another class. Put simply, Float and Double should not support succ and pred (unless, perhaps, they map to the next greater/lesser representable number, which would also be confusing). I can even see an argument for not allowing Float or Double to be used for ranges either, as the steps may not be exact, which in practice turns out to be very confusing.
Speaking of confusing, try [0, 0.3 .. 2]::[Rational] Also, toEnum and fromEnum would make more sense mapping from and to Integer. It seems that succ and pred are unused.