Re: [Haskell-cafe] librar...@haskell.org (was: GHC and backwards compatibility)
On 8/19/2013 2:43 PM, Ketil Malde wrote: Joe Q headprogrammingc...@gmail.com writes: This is definitely an issue with the array package not setting the right minimum versions. You should email the maintainer. Yes, that would be the thing to do, except that the maintainer is librar...@haskell.org, whom I believe does not accept emails from me. :-( But if you (or anybody else) subscribes to the list, perhaps you could forward? In any case, one of the dependencies uses Stringable, which means that a newer GHC is probably still required. -k The libraries@ address is just a mailman list. Perhaps it should be set to allow non-subscribers to post. Not allowing the general public to email the posted maintainer of the standard library is ridiculous. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Alternative name for return
On 8/7/2013 11:00 AM, David Thomas wrote: twice :: IO () - IO () twice x = x x I would call that evaluating x twice (incidentally creating two separate evaluations of one pure action description), but I'd like to better see your perspective here. x is only evaluated once, but /executed/ twice. For IO, that means magic. For other types, it means different things. For Identity, twice = id! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: tasty, a new testing framework
On 8/5/2013 2:48 PM, Roman Cheplyaka wrote: I am pleased to announce the first release of tasty, a new testing framework for Haskell. It is meant to be a successor to test-framework (which is unmaintained). Tasty supports HUnit, SmallCheck, QuickCheck, and golden tests out of the box (through the standard packages), but it is very extensible, so you can write your own test providers. Please see the home page for more information: http://documentup.com/feuerbach/tasty Roman ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe Will tasty be available through yum? *ducks* ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Question about Newtype op() function arguments.
On 6/7/2013 4:51 PM, Tom Ellis wrote: On Fri, Jun 07, 2013 at 04:05:09PM -0400, Joe Q wrote: The phantom parameter solves the same problem as scoped type variables. Granted, if you find yourself in that kind of polymorphic soup you have deeper problems... I don't understand this. Scoped type variables are used when you want to use a type variable from the top level within the body of a function. If you use op and specify a particular constructor then you don't have a variable but a concrete instance of a type. But maybe I'm missing some more powerful way this can be used ... Tom You can use scoped type variables to correct an ambiguous type error. You can think of op as a variation on asTypeOf, as documented here on http://www.haskell.org/haskellwiki/Scoped_type_variables#Avoiding_Scoped_Type_Variables. If I tried to come up with an example that's specific to op, it would only be horribly contrived. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Hackage checking maintainership of packages
And we can have something on hackage that does this check automatically! And we can put unmaintained in the description! And then we can leave it unmaintained! Unmaintained should have its own flag, I think... On 5/5/2013 2:28 PM, Petr Pudlák wrote: I'd say: - If a package has UNMAINTAINED (perhaps also DEPRECATED?) somewhere in its title/description, don't do anything. - Otherwise if the package hasn't been updated for past 3 months, send a quarterly reminder (including the information under what conditions the reminder is sent). 2013/5/5 Doug Burke dburke...@gmail.com mailto:dburke...@gmail.com On May 5, 2013 7:25 AM, Petr Pudlák petr@gmail.com mailto:petr@gmail.com wrote: Hi, on another thread there was a suggestion which perhaps went unnoticed by most: -- Forwarded message -- From: Niklas Hambüchen m...@nh2.me mailto:m...@nh2.me Date: 2013/5/4 ... I would even be happy with newhackage sending every package maintainer a quarterly question Would you still call your project X 'maintained'? for each package they maintain; Hackage could really give us better indications concerning this. This sounds to me like a very good idea. It could be as simple as If you consider yourself to be the maintainer of package X please just hit reply and send. If Hackage doesn't get an answer, it'd just would display some red text like This package seems to be unmaintained since D.M.Y. Best regards, Petr For those packages that give a repository, a query could be done automatically to see when it was last updated. It's not the same thing as 'being maintained', but is less annoying for those people with many packages on hackage. Doug ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Looking for portable Haskell or Haskell like language
If you are feeling brave, you can also bootstrap GHC. For operating systems that are already supported, it should not be too hard. Last time I tried on a fresh install of Debian, the process was to install the dependencies, and then something like this: sh configure make make install Disclaimer: this was with 7.4.1, which was a while ago. I don't remember if that's all there was to it. On 4/27/2013 7:12 AM, Daniel Fischer wrote: On Saturday 27 April 2013, 19:18:35, Andrew Cowie wrote: On Fri, 2013-04-26 at 21:21 -0800, Christopher Howard wrote: Hi. I've got this work situation where I've got to do all my work on /ancient/ RHEL5 systems, with funky software configurations, and no root privileges. I wanted to install GHC in my local account, but the gnu libc version is so old (2.5!) that I can't even get the binary packages to install. Silly question, but have you tried *building GHC from source*? Building GHC is non-trivial, but basically boils down to having an existing ghc that runs enough to bootstrap, right? So you can take a (quite old, sure, no problem) ghc out of the RHEL 5 repositories and use that to build a current GHC 7.6 say. It's not quite as convenient as that, since you need a new enough GHC to build 7.6 (not sure which version is required). So you'd probably need to build one or two intermediate GHCs from source, depending on what you can directly install. Building from source isn't so difficult, you need a gcc, you need to install happy and alex (sufficiently old versions for the start, install the newest versions before you build the final GHC), and of course a working GHC. ./configure --prefix=$HOME (or where you want to install GHC) make make install You then have a lot of time to drink tea. That _would_ be linked against whatever library stack you have present, and you should be ok from there. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Why were datatype contexts removed instead of fixing them?
From what I have heard, they are completely subsumed by GADTs, which is a stable enough extension that it was considered unimportant to save. Your Foo would be something like this: data Foo a where Foo :: Eq a = a - Foo a On 4/25/2013 6:38 AM, harry wrote: If I understand correctly, the problem with datatype contexts is that if we have e.g. data Eq a = Foo a = Foo a the constraint Eq a is thrown away after a Foo is constructed, and any method using Foos must repeat Eq a in its type signature. Why were these contexts removed from the language, instead of fixing them? PS This is following up on a discussion on haskell-beginners, How to avoid repeating a type restriction from a data constructor. I'm interested in knowing whether there's a good reason not to allow this, or if it's just a consequence of the way type classes are implemented by compilers. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: Nomyx 0.1 beta, the game where you can change the rules
On 2/28/2013 11:17 PM, Chris Wong wrote: On Wed, Feb 27, 2013 at 8:37 AM, Corentin Dupontcorentin.dup...@gmail.com wrote: Hi Chris, Thanks! That's true for the user number. What should I do? Encrypt it? It's not that you have a user number, or even that it's accessible: it's that it's the entirety of access control, meaning that if the user changes it they can masquerade as another user. The correct solution is that a user should authenticate, which creates a session hash that you stash away and also send back to the user as a cookie so the browser will present it on accesses. Then you check that the presented hash is there and matches the session hash. These should expire periodically, requiring the user to log back in again. Additionally, you can change the session hash with every page hit, to some other totally random hash. If someone steals your session, they had better act on it immediately, lest you visit another page and it changes completely. If your session gets hijacked, you get logged out. When you log in again the attacker loses access. You can also check sessions by the hash and IP address. That has usability concerns though. Even if players never switch machines in the middle of a game, suppose you are playing on a cell phone and your train goes through a tunnel. When you reconnect, your provider gives you a different IP and you are logged out. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
