Re: Reform of the Monad, and Disruptive Change

2011-02-04 Thread Malcolm Wallace
On 4 Feb 2011, at 09:41, John Smith wrote: There has been a fair amount of discussion, both on this list and libraries, regarding the Monad class hierarchy. The many on the libraries list expressed support for the patch at http://hackage.haskell.org/trac/ghc/ticket/4834 , conditional on it

Re: Reform of the Monad, and Disruptive Change

2011-02-04 Thread Dark Lord
On 04/02/2011 12:08, Malcolm Wallace wrote: I suggested, and several people +1'd, that if we are making disruptive changes to the standard libraries defined in the Language Report (especially the Prelude), then we should aim to make a thorough job of cleaning up all the cruft and redesigning

Re: Reform of the Monad, and Disruptive Change

2011-02-04 Thread Howard B. Golden
John Smith volderm...@hotmail.com asked: What is the best way out of this deadlock? My suggestions: * If possible, make the change optional. As an example, create a second (third, etc.) Prelude with the new features without abandoning the current Prelude. Let the user choose the Prelude

Re: Reform of the Monad, and Disruptive Change

2011-02-04 Thread Roman Leshchinskiy
On 04/02/2011, at 10:49, Dark Lord wrote: I thoroughly agree with this. However, in the event that this does not happen, piecemeal fixes are better than none. FWIW, I disagree. To put it bluntly, why is repeatedly breaking a lot of code better than not breaking it at all? Breaking a lot of

Re: Reform of the Monad, and Disruptive Change

2011-02-04 Thread Roman Leshchinskiy
On 04/02/2011, at 10:08, Malcolm Wallace wrote: I suggested, and several people +1'd, that if we are making disruptive changes to the standard libraries defined in the Language Report (especially the Prelude), then we should aim to make a thorough job of cleaning up all the cruft and

Re: Reform of the Monad, and Disruptive Change

2011-02-04 Thread Daniel Peebles
Perhaps GHC could be released with two sets of libraries. This would give people time to experiment without breaking existing code. It would also make implementing individual changes much easier. I fully support this. {-# LANGUAGE NewPrelude #-} or something similar would be wonderful.

Re: Reform of the Monad, and Disruptive Change

2011-02-04 Thread Brandon S Allbery KF8NH
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 2/4/11 14:30 , Daniel Peebles wrote: Perhaps GHC could be released with two sets of libraries. This would give people time to experiment without breaking existing code. It would also make implementing individual changes much easier.