[Haskell-cafe] Why aren't Float and Double Bounded?

[Jules Bean]

Josh Lee wrote:
> On Tue, 27 Nov 2007 14:41:59 -0500
> Isaac Dupree <isaacdupree at charter.net> wrote:
> 
>> Henning Thielemann wrote:
>>> On Mon, 26 Nov 2007, Jason Dusek wrote:
>>>
>>>> Among numeric types, it seems that only integer types are Bounded.
>>> Maybe because IEEE format supports Infinity?
>> therefore, maxBound is Infinity and minBound negative infinity?
> 
> Using Infinity would go against the meaning of Enum. In the
> Double/Float types, succ and pred mean "add/subtract 1.0", as opposed
> to the unit of least precision. In fact, succ and pred lose meaning
> once the precision of the floats exceeds a certain value.

That's not the meaning of Enum.

That's brokenness :)

It's there so that [1..10] :: [Double] works, but it's a horrible 
horrible thing. The overloaded [a..b] notation should not be in Enum but 
some other class (I suggest ICanHazInturval as the class name).

Oh well.

Jules