[Haskell-cafe] instance Enum Double considerednotentirelygreat?

Chris Smith cdsmith at gmail.com
Tue Sep 27 20:12:57 CEST 2011

On Tue, 2011-09-27 at 09:23 -0700, Donn Cave wrote:
> I think it's more than reasonable to expect
>   [0.1,0.2..0.5] == [0.1,0.2,0.3,0.4,0.5]
> and that would make everyone happy, wouldn't it?

But what's the justification for that?  It *only* makes sense because
you used short decimal literals.  If the example were:

let a = someComplicatedCalculation
    b = otherComplicatedCalculation
    c = thirdComplicatedCalculation
in  [a, b .. c]

then it would be far less reasonable to expect the notation to fudge the
numbers in favor of obtaining short decimal representations, which is
essentially what you're asking for.


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