Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Gregory Collins
On Fri, May 3, 2013 at 6:48 AM, Adrian May wrote: > May I venture a guess that you never tried to manage a 5-10 million line > project? > I build a project a couple orders of magnitude bigger than that dozens of times every day. Similar stories are not uncommon among people who inhabit this list.

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Simon Peyton-Jones
One of the great things about the Haskell mailing lists is the supportive, respectful tone that is the dominant mode of discourse. I sense that things are getting a little out of control in this particular thread. Even though this particular issue is clearly extremely frustrating for those inv

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Adrian May
> > > you've let a 5-10 million line project spiral out of control without > putting the necessary software engineering infrastructure and controls in > place ... This issue you're having reflects a lot more strongly on your > technical culture than it does on any instability in GHC. > I can't di

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Raphael Gaschignard
On Fri, May 3, 2013 at 4:37 PM, Simon Peyton-Jones wrote: > One of the great things about the Haskell mailing lists is the > supportive, respectful tone that is the dominant mode of discourse. I > sense that things are getting a little out of control in this particular > thread. Even though thi

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Ertugrul Söylemez
Adrian May wrote: > I really don't know why somebody can't make a simple and well > intentioned point without getting attacked by people who feel > threatened over every little thing. It's because we're failing to see the problem. I mean, if you can pinpoint the source of your problems we could

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Ertugrul Söylemez
Raphael Gaschignard wrote: > I'm pretty sure most of us have experienced some issue with > dependencies breaking , and its probably the most frustrating problem > we can have have in any language. It's hard not to take this all a bit > personally. Maybe if we think more about how to solve this (g

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Adrian May
How about this: can you guys give me a detailed example of a justified deprecation: one so extremely obviously called for that even I would agree. I just want to understand the kind of logic that's applied over these things. ___ Haskell-Cafe mailing list

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Neil Davies
Isn't this a problem of timescale? Nothing can be backward compatible for ever (or at least nothing that is being developed or maintained) There will be, in the life of non-trival length project, change. We rely (and I mean rely) on Haskell s/w that was written over 10 years ago - we accept th

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Ertugrul Söylemez
Adrian May wrote: > How about this: can you guys give me a detailed example of a justified > deprecation: one so extremely obviously called for that even I would > agree. I just want to understand the kind of logic that's applied over > these things. Changes already made in the base library or i

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Ertugrul Söylemez
Neil Davies wrote: > Isn't this a problem of timescale? > > Nothing can be backward compatible for ever (or at least nothing that > is being developed or maintained) I was referring to the Dependency Hell. I don't consider breaking changes a problem. Greets, Ertugrul -- Key-ID: E5DD8D11 "Er

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Adrian May
> > Changes already made in the base library or in one of the platform > libraries: > So could you pick the most unassailable and tell me more about it please? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Guy
Ertugrul Söylemez wrote: Often demanded changes that may or may not happen in the future: * base: Make Functor a superclass of Monad. One of the two most commonly demanded change to the base library. Will break lots and lots of code. Reason: Would greatly simplify a lot of code.

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Tobias Dammers
On Fri, May 03, 2013 at 01:23:55PM +0300, Guy wrote: > That's what I thought of when I saw the original complaint - GHC is > too backwards compatible! There's far too much boilerplate because > of the Functor => Applicative => Monad mess. Float/Double being > Enums is ridiculous. None of this gets

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Adrian May
> > > PS The proposal to fix Functor => Applicative => Monad has patches > attached for GHC and base, but the backwards compatibility bogeyman always > seems to trump something that will break a lot of code. I think that should be fixed as well, but it would be tantamount to a new language. I gu

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Ertugrul Söylemez
Adrian May wrote: > > Changes already made in the base library or in one of the platform > > libraries: > > So could you pick the most unassailable and tell me more about it > please? I'll just pick a random example: Eq and Show are no longer superclasses of Num. I'm the author of the Netwire

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Michael Sloan
Dependency breakage is certainly an unavoidable problem. However, I think Haskell is also in a much better position for having a technical solution to the frustration of breakages. Barring issues with changing datatypes / class instances, we can already express many of the API changes you'd want

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Adrian May
On 3 May 2013 18:56, Ertugrul Söylemez wrote: > Adrian May wrote: > > > > Changes already made in the base library or in one of the platform > > > libraries: > > > > So could you pick the most unassailable and tell me more about it > > please? > > I'll just pick a random example: Eq and Show ar

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread David Thomas
I'd also like to see these two. It occurs to me there may be language tweak that could reduce breakage and add some convenience in both cases. It would not surprise me at all if this has been thought of, examined, and discarded, but I don't have time to dig so I'll just lay it out quickly, and if

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Tom Ellis
On Fri, May 03, 2013 at 09:34:21PM +0800, Adrian May wrote: > I never doubted that people add new stuff for valid reasons. What I'm > interested in is whether or not it could have been done without breaking > anything. But having thought about it for a while, I'm tending to think > that version con

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Alexander Solla
On Fri, May 3, 2013 at 6:34 AM, Adrian May wrote: > > > > On 3 May 2013 18:56, Ertugrul Söylemez wrote: > >> Adrian May wrote: >> >> > > Changes already made in the base library or in one of the platform >> > > libraries: >> > >> > So could you pick the most unassailable and tell me more about i

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Brandon Allbery
On Fri, May 3, 2013 at 5:30 AM, Adrian May wrote: > How about this: can you guys give me a detailed example of a justified > deprecation: one so extremely obviously called for that even I would agree. > I just want to understand the kind of logic that's applied over these > things. > This might n

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Adrian May
> > > Barring issues with changing datatypes / class instances, we can already > express many of the API changes you'd want to make to some library [1]. > Now, no one actually does what this proposal suggests - it's a lot of > work, and it doesn't work in general. However, the fact that Haskell m

Re: [Haskell-cafe] Lambda Calculus question on equivalence

2013-05-03 Thread Andreas Abel
The answer to your question is given in Boehm's theorem, and the answer is "no", as you suspect. For the untyped lambda-calculus, alpha-equivalence of beta-eta normal forms is the same as observational equivalence. Or put the other way round, two normal forms which are not alpha-equivalent ca

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Ozgur Akgun
Hi, On 3 May 2013 11:43, Tobias Dammers wrote: > > PS The proposal to fix Functor => Applicative => Monad has patches > > attached for GHC and base, but the backwards compatibility bogeyman > > always seems to trump something that will break a lot of code. > > This kind of "breaks everything" ch

[Haskell-cafe] runhaskell flags: What is going on?

2013-05-03 Thread Niklas Hambüchen
> runhaskell -fno-warn-unused-matches Myfile.hs [some compile error] > runhaskell -fno-warn-unused-matches Myfile.hs [no output whatsoever but exit code 127] > runhaskell -asdf Myfile.hs ghc: unrecognised flags: -asdf > runhaskell -fasdf Myfile.hs [no output whatsoever but exit code 127] Not s

Re: [Haskell-cafe] runhaskell flags: What is going on?

2013-05-03 Thread Brandon Allbery
On Fri, May 3, 2013 at 10:35 AM, Niklas Hambüchen wrote: > > runhaskell -fno-warn-unused-matches Myfile.hs > [some compile error] > > > runhaskell -fno-warn-unused-matches Myfile.hs > [no output whatsoever but exit code 127] > > > runhaskell -asdf Myfile.hs > ghc: unrecognised flags: -asdf > > >

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Guy
David Thomas wrote: I'd also like to see these two. It occurs to me there may be language tweak that could reduce breakage and add some convenience in both cases. It would not surprise me at all if this has been thought of, examined, and discarded, but I don't have time to dig so I'll just la

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread David Thomas
That's approximately what I was describing, yes. Thanks! On Fri, May 3, 2013 at 7:54 AM, Guy wrote: > David Thomas wrote: > >> I'd also like to see these two. It occurs to me there may be language >> tweak that could reduce breakage and add some >> convenience in both cases. It would not sur

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Adrian May
I'm having a bit of trouble getting my brain around that, but if anybody cares about attracting new users, that might be relevant in itself. Perhaps I could be seen as an example of your swing-state. I'm no Haskell expert but I'd like to push it if I could cos I'm so sick of seeing huge codebases l

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread David Thomas
That's approximately what I was describing, yes. Thanks! On Fri, May 3, 2013 at 7:54 AM, Guy wrote: > David Thomas wrote: > >> I'd also like to see these two. It occurs to me there may be language >> tweak that could reduce breakage and add some >> convenience in both cases. It would not sur

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Brandon Allbery
On Fri, May 3, 2013 at 10:54 AM, Guy wrote: > http://hackage.haskell.org/**trac/ghc/wiki/**DefaultSuperclassInstances > > I'm surprised that the various superclass proposals haven't got more > attention, seeing as it would allow

Re: [Haskell-cafe] Lambda Calculus question on equivalence

2013-05-03 Thread Francesco Mazzoli
At Fri, 03 May 2013 16:34:28 +0200, Andreas Abel wrote: > The answer to your question is given in Boehm's theorem, and the answer > is "no", as you suspect. > > For the untyped lambda-calculus, alpha-equivalence of beta-eta normal > forms is the same as observational equivalence. Or put the oth

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Tobias Dammers
On Fri, May 03, 2013 at 03:35:08PM +0100, Ozgur Akgun wrote: > Hi, > > On 3 May 2013 11:43, Tobias Dammers wrote: > > > > PS The proposal to fix Functor => Applicative => Monad has patches > > > attached for GHC and base, but the backwards compatibility bogeyman > > > always seems to trump somet

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Niklas Hambüchen
While I certainly enjoy the discussion, how about addressing one of the original problems: On 02/05/13 13:27, Adrian May wrote: > I just tried to use Flippi. It broke because of the syntax change so I > tried WASH. I couldn't even install it because of the syntax change. I just fixed that in http

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Edward Kmett
"Tantamount to a new language" to fix a minor detail in a typeclass hierarchy? That is just histrionic. *No* language is that stable. Scala makes dozens of changes like that between *minor* versions, and while I hardly hold up their development practices as the best in the industry it is still som

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Edward Kmett
So basically it boiled down drop the haskell98 package dependency and use the new exception system, and import the right things to avoid the use of the no longer exported Prelude catch? On Fri, May 3, 2013 at 12:44 PM, Niklas Hambüchen wrote: > While I certainly enjoy the discussion, how about

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Bardur Arantsson
On 05/03/2013 06:44 PM, Niklas Hambüchen wrote: > While I certainly enjoy the discussion, how about addressing one of the > original problems: > > On 02/05/13 13:27, Adrian May wrote: >> I just tried to use Flippi. It broke because of the syntax change so I >> tried WASH. I couldn't even install i

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Bardur Arantsson
On 05/03/2013 06:49 PM, Edward Kmett wrote: > "Tantamount to a new language" to fix a minor detail in a typeclass > hierarchy? That is just histrionic. *No* language is that stable. > > Scala makes dozens of changes like that between *minor* versions, and while > I hardly hold up their development

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Tom Murphy
On Thu, May 2, 2013 at 9:48 PM, Adrian May wrote: > > > Is anybody in the Haskell community still interested in attracting new > users? If so I suggest you go play with Ruby on Rails. Then you'll know > what it's like to approach a complex and unfamiliar system where every > crumb requires a preci

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Hilco Wijbenga
On 3 May 2013 09:44, Niklas Hambüchen wrote: > While I certainly enjoy the discussion, how about addressing one of the > original problems: > > On 02/05/13 13:27, Adrian May wrote: >> I just tried to use Flippi. It broke because of the syntax change so I >> tried WASH. I couldn't even install it b

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Nicolas Trangez
On Fri, 2013-05-03 at 10:40 -0700, Hilco Wijbenga wrote: > On 3 May 2013 09:44, Niklas Hambüchen wrote: > > While I certainly enjoy the discussion, how about addressing one of the > > original problems: > > > > On 02/05/13 13:27, Adrian May wrote: > >> I just tried to use Flippi. It broke because

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Niklas Hambüchen
On 04/05/13 01:52, Nicolas Trangez wrote: > On Fri, 2013-05-03 at 10:40 -0700, Hilco Wijbenga wrote: >> Given the apparent simplicity of the changes needed to keep one's >> Haskell code up to snuff and the strong typing inherent in Haskell >> code, would it not be possible to create something simil

[Haskell-cafe] A three page web application in a tweet (in Haskell)

2013-05-03 Thread Alberto G. Corona
Hi, Just to share my excitement with you: https://twitter.com/AGoCorona/status/329648864082677760 See the link in the tweet for an explanation Best Regards, -- Alberto. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mail

Re: [Haskell-cafe] Backward compatibility

2013-05-03 Thread Niklas Hambüchen
All right, here you go: https://github.com/nh2/WashNGo https://github.com/nh2/WashNGo/commit/08010e7404219470a827f3e4172004f9d2aedc29 Took me around 75 minutes. Think about it a bit: I just ported thirty thousand lines of code that I have never seen before and that has bit-rotted for over six y

Re: [Haskell-cafe] runhaskell flags: What is going on?

2013-05-03 Thread Niklas Hambüchen
Not sure what you mean; if I just run `runhaskell`, it reads from stdin. In any way, if runhaskell exits with error code 127, should it not print what the error is? On Fri 03 May 2013 22:48:33 SGT, Brandon Allbery wrote: > If you type just 'runhaskell' you will get an error message which > expla

Re: [Haskell-cafe] BayHac '13

2013-05-03 Thread Mark Lentczner
*Update:* - BayHac '13 is just *two weeks away*. - We have *over 60* sign-ups! - Please sign up, if you haven't already. - We've added an optiona