Re: FW: 7.4.1-pre: Show & Integral
On Sat, Dec 24, 2011 at 12:37 PM, Ian Lynagh wrote: > On Fri, Dec 23, 2011 at 05:41:23PM +, Simon Peyton-Jones wrote: >> I'm confused too. I'd welcome clarification from the Haskell Prime folk. > > We use the library process to agree changes to the libraries, and > Haskell' should then incorporate the changes into the next version of > the standard. FWIW, the library change process is nowhere near rigorous enough to decide what should go into a language standard. Not that some good ideas have not been explored, but before adding them to a language standard, they would require considerably more discussion. John ___ Haskell-prime mailing list Haskell-prime@haskell.org http://www.haskell.org/mailman/listinfo/haskell-prime
Re: FW: 7.4.1-pre: Show & Integral
On Fri, Dec 23, 2011 at 05:41:23PM +, Simon Peyton-Jones wrote: > I'm confused too. I'd welcome clarification from the Haskell Prime folk. We use the library process to agree changes to the libraries, and Haskell' should then incorporate the changes into the next version of the standard. Thanks Ian ___ Haskell-prime mailing list Haskell-prime@haskell.org http://www.haskell.org/mailman/listinfo/haskell-prime
Re: FW: 7.4.1-pre: Show & Integral
Hello, The discussion on the libraries list is archived here: http://www.haskell.org/pipermail/libraries/2011-September/016699.html There hasn't been a corresponding discussion for Haskell Prime so, technically, GHC deviates from the standard. -Iavor On Fri, Dec 23, 2011 at 9:41 AM, Simon Peyton-Jones wrote: > I'm confused too. I'd welcome clarification from the Haskell Prime folk. > > S > > -Original Message- > From: Serge D. Mechveliani [mailto:mech...@botik.ru] > Sent: 23 December 2011 17:36 > To: Simon Peyton-Jones > Subject: Re: 7.4.1-pre: Show & Integral > > On Thu, Dec 22, 2011 at 08:14:54PM +, Simon Peyton-Jones wrote: >> | 2011/12/22 Edward Kmett : >> | > 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. >> | >> | Is it reasonable to enquire how many standard-compliant implementations >> | of Haskell there are? >> >> Just to be clear, the change IS the standard. GHC has to change to be >> compliant. >> At least that's how I understand it. > > > I am confused. > I am looking now at the on-line specification of Haskell-2010, > 6.3 Standard Haskell Classes. > It shows that Integral includes Show: > > Eq Show > \ / > Num > | > Enum Real > \ | > Integral > > This is also visible in the further standard class declarations in this > chapter. > > Hence, for `x :: Integral a => a' it is correct to write (shows x ""). > And ghc-7.4.0.20111219 does not allow this. > So, ghc-7.4.0.20111219 breaks the 2010 standard. Now, Edward Kmett writes > that > this break is done deliberately. > > Am I missing something? > > I witness this for the first time: that GHC deliberately breaks the current > Haskell standard. > Probably, many people (as myself) dislike this point of the standard. > Well, they can write a dummy Show implementation for their type T: > showsPrec _ _ = showString "( :: T)", > > and wait for an improved standard, say, Haskell-II > -- ? > > Regards, > > -- > Sergei > mech...@botik.ru > > > > > > > ___ > Haskell-prime mailing list > Haskell-prime@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-prime ___ Haskell-prime mailing list Haskell-prime@haskell.org http://www.haskell.org/mailman/listinfo/haskell-prime
FW: 7.4.1-pre: Show & Integral
I'm confused too. I'd welcome clarification from the Haskell Prime folk. S -Original Message- From: Serge D. Mechveliani [mailto:mech...@botik.ru] Sent: 23 December 2011 17:36 To: Simon Peyton-Jones Subject: Re: 7.4.1-pre: Show & Integral On Thu, Dec 22, 2011 at 08:14:54PM +, Simon Peyton-Jones wrote: > | 2011/12/22 Edward Kmett : > | > 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. > | > | Is it reasonable to enquire how many standard-compliant implementations > | of Haskell there are? > > Just to be clear, the change IS the standard. GHC has to change to be > compliant. > At least that's how I understand it. I am confused. I am looking now at the on-line specification of Haskell-2010, 6.3 Standard Haskell Classes. It shows that Integral includes Show: Eq Show \ / Num | Enum Real \ | Integral This is also visible in the further standard class declarations in this chapter. Hence, for `x :: Integral a => a' it is correct to write (shows x ""). And ghc-7.4.0.20111219 does not allow this. So, ghc-7.4.0.20111219 breaks the 2010 standard. Now, Edward Kmett writes that this break is done deliberately. Am I missing something? I witness this for the first time: that GHC deliberately breaks the current Haskell standard. Probably, many people (as myself) dislike this point of the standard. Well, they can write a dummy Show implementation for their type T: showsPrec _ _ = showString "( :: T)", and wait for an improved standard, say, Haskell-II -- ? Regards, -- Sergei mech...@botik.ru ___ Haskell-prime mailing list Haskell-prime@haskell.org http://www.haskell.org/mailman/listinfo/haskell-prime
