Re: [Haskell-cafe] Bug with [Double]

* Ben Millwood wrote:

...

Prelude> [1,1+2/3..10] :: [Rational] [1 % 1,5 % 3,7 % 3,3 % 1,11 % 3,13 % 3,5 % 1,17 % 3,19 % 3,7 % 1,23 % 3,25 % 3,9 % 1,29 % 3,31 % 3]

Same result.

This sounds like a bug to me. The section of the Haskell Report that deals with the Enum class mentions Float and Double, not Rational, and there's really no sensible reason why Rationals would exhibit this behaviour given that they don't have rounding error.

Double is not better: Prelude> [9,9+2/3..10] [9.0,9.666666666666666,10.333333333333332] Prelude> [7,9 .. 10] [7,9]