7.4.1-pre: Show & Integral

Edward Kmett ekmett at gmail.com
Thu Dec 22 20:16:07 CET 2011

7.0.x agrees with the standard.

The change, however, was a deliberate _break_ with the standard that passed through the library review process a few months ago, and is now making its way out into the wild. 

The simplest fix is to simply add an Eq or Show constraint to the few functions that need them and which had been constrained by Num, or in your case Integral.

The resulting code will then be compatible with both GHC and Haskell 2010, where it will simply ignore the extra constraint, but it permits folks who want Num instances for free modules such as functions to not have to lie claiming that they can show the function or compare them for equality.

Sent from my iPhone

On Dec 22, 2011, at 9:52 AM, "Serge D. Mechveliani" <mechvel at botik.ru> wrote:

> пDear GHC team,
> ghc-7.0.1           assumes that  Integral includes Show,  and
> ghc-  does not assume this.
> Which one agrees with Haskell-2010 ?
> Regards, 
> ------
> Sergei
> mechvel at botik.ru
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