Re: [Haskell-cafe] [Haskell] [ANN] GenCheck - a generalized property-based testing framework
Hi, 1. Minor correction for your tutorial: reverse . reverse = id is called the involution property, not idempotency. 2. Writing haddock documentation would definitely increase the chances for GenCheck wide adoption. -- Roman I. Cheplyaka :: http://ro-che.info/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [Haskell] [ANN] GenCheck - a generalized property-based testing framework
On Tue, Jun 19, 2012 at 4:04 PM, Jacques Carette care...@mcmaster.cawrote: User beware: this is gencheck-0.1, there are still a few rough edges. We plan to add a Template Haskell feature to this which should make deriving enumerators automatic for version 0.2. Can you provide me a quick pointer into what methods need to be generated automatically? Thanks, Pedro ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [Haskell] [ANN] GenCheck - a generalized property-based testing framework
On 12-06-23 04:26 AM, Roman Cheplyaka wrote: Hi, 1. Minor correction for your tutorial: reverse . reverse = id is called the involution property, not idempotency. Indeed! Fixed, thanks. 2. Writing haddock documentation would definitely increase the chances for GenCheck wide adoption. Absolutely - I am working on that now. It was always the plan, but we were sitting on GenCheck for too long, so I decided to push out an early 0.1 release and fix that up for 0.2 Jacques ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [Haskell] [ANN] GenCheck - a generalized property-based testing framework
On 12-06-23 04:38 AM, José Pedro Magalhães wrote: On Tue, Jun 19, 2012 at 4:04 PM, Jacques Carette care...@mcmaster.ca mailto:care...@mcmaster.ca wrote: User beware: this is gencheck-0.1, there are still a few rough edges. We plan to add a Template Haskell feature to this which should make deriving enumerators automatic for version 0.2. Can you provide me a quick pointer into what methods need to be generated automatically? Sure. Given a data definition such as data Zipper a = Zip ![a] ![a] deriving (Eq,Show) (where the strictness annotations are not relevant), one would want to automatically generate instance Enumerated Zipper where enumeration = eMemoize $ eProd Zip (eList A) (eList A) and for data BinTree a = BTNode a | BTBr (BinTree a) (BinTree a) generate instance Enumerated (BinTree Label) where enumeration = eMemoize $ eSum (eNode (BTNode A)) (eProd BTBr eBinTree eBinTree) Jacques ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] transformers problem: Could not deduce MonadTrans (StateT s) ??
Why this function doesn't compile? phi :: Monad m = StateT s m () phi = lift $ return () I get (ghc-7.4.1) Could not deduce (MonadTrans (StateT s)) arising from a use of `lift' from the context (Monad m) bound by the type signature for phi :: Monad m = StateT s m () at FSMt.hs:28:1-22 Possible fix: add (MonadTrans (StateT s)) to the context of the type signature for phi :: Monad m = StateT s m () or add an instance declaration for (MonadTrans (StateT s)) In the expression: lift In the expression: lift $ return () In an equation for `phi': phi = lift $ return () Failed, modules loaded: none. Anton ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANNOUNCE: dbus 0.10
This is completing the merger of the dbus-core and dbus-client packages. The new package does everything they can do, but better. Hackage: http://hackage.haskell.org/package/dbus Homepage: https://john-millikin.com/software/haskell-dbus/ API reference: https://john-millikin.com/software/haskell-dbus/reference/haskell-dbus/0.10/ Examples: Included in the tarball, and also at https://john-millikin.com/branches/haskell-dbus/0.10/head:/examples/ Notable changes: * The module hierarchy was simplified. Most users will only ever need the DBus and DBus.Client modules. * Exports which were not used or useful have been removed. * Much better documentation -- most exports now have a description, and several have examples. * The source code isn't literate any more. Too many people expressed frustration at trying to contribute, so I just converted it all to standard flat .hs files. * Better support for custom socket transports and authentication mechanisms. * Added support for listening for socket connections. This allows users to implement both sides of a peer-peer session. * Various improvements to performance, including moving from binary to cereal. * Various minor improvements to correctness. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] transformers problem: Could not deduce MonadTrans (StateT s) ??
On Sat, Jun 23, 2012 at 12:22 PM, Anton Kholomiov anton.kholom...@gmail.com wrote: Why this function doesn't compile? phi :: Monad m = StateT s m () phi = lift $ return () I get (ghc-7.4.1) Could not deduce (MonadTrans (StateT s)) arising from a use of `lift' from the context (Monad m) This means exactly what it says: you have stated that m must be a Monad, but you didn't say anything about whether it's a MonadTrans, so you can't use lift. The correct signature would be phi :: (Monad m, MonadTrans m) = StateT s m () -- brandon s allbery allber...@gmail.com wandering unix systems administrator (available) (412) 475-9364 vm/sms ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] transformers problem: Could not deduce MonadTrans (StateT s) ??
No, it wants me to define an instance for (StateT s) which is supposed to be defined be the authors of the library. Actually I discovered that I have two libraries called transformers. transformers-0.2.2.0 transformers-0.3.0.0 So when I'm doing import Control.Monad.Trans (0.2.2.0) I get the error And when I'm doing import Control.Monad.Trans.Class (0.3.0.0) It compiles. Anton ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] transformers problem: Could not deduce MonadTrans (StateT s) ??
At last.. No, it wants me to define an instance for (StateT s) which is supposed to be defined be the authors of the library. Actually I discovered that I have two libraries called transformers. transformers-0.2.2.0 transformers-0.3.0.0 So when I'm doing import Control.Monad.Trans (0.2.2.0) I get the error And when I'm doing import Control.Monad.Trans.Class (0.2.2.0) It compiles. Anton ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] transformers problem: Could not deduce MonadTrans (StateT s) ??
On 23 Jun 2012, at 21:27, Anton Kholomiov wrote: At last.. No, it wants me to define an instance for (StateT s) which is supposed to be defined be the authors of the library. Actually I discovered that I have two libraries called transformers. transformers-0.2.2.0 transformers-0.3.0.0 So when I'm doing import Control.Monad.Trans (0.2.2.0) Ehm... seems like you're importing mtl instead of transformers. AFAIK there is no Control.Monad.Trans module in transformers. I get the error And when I'm doing import Control.Monad.Trans.Class (0.2.2.0) It compiles. Anton ___ 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] transformers problem: Could not deduce MonadTrans (StateT s) ??
Indeed, thank you. mtl is cruel with me for the second time uumpf. But it's strange mtl just reexports transformer's module 2012/6/23 MigMit miguelim...@yandex.ru On 23 Jun 2012, at 21:27, Anton Kholomiov wrote: At last.. No, it wants me to define an instance for (StateT s) which is supposed to be defined be the authors of the library. Actually I discovered that I have two libraries called transformers. transformers-0.2.2.0 transformers-0.3.0.0 So when I'm doing import Control.Monad.Trans (0.2.2.0) Ehm... seems like you're importing mtl instead of transformers. AFAIK there is no Control.Monad.Trans module in transformers. I get the error And when I'm doing import Control.Monad.Trans.Class (0.2.2.0) It compiles. Anton ___ 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] transformers problem: Could not deduce MonadTrans (StateT s) ??
Maybe I export State from one library version and instance from another? 2012/6/23 Anton Kholomiov anton.kholom...@gmail.com Indeed, thank you. mtl is cruel with me for the second time uumpf. But it's strange mtl just reexports transformer's module 2012/6/23 MigMit miguelim...@yandex.ru On 23 Jun 2012, at 21:27, Anton Kholomiov wrote: At last.. No, it wants me to define an instance for (StateT s) which is supposed to be defined be the authors of the library. Actually I discovered that I have two libraries called transformers. transformers-0.2.2.0 transformers-0.3.0.0 So when I'm doing import Control.Monad.Trans (0.2.2.0) Ehm... seems like you're importing mtl instead of transformers. AFAIK there is no Control.Monad.Trans module in transformers. I get the error And when I'm doing import Control.Monad.Trans.Class (0.2.2.0) It compiles. Anton ___ 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] ANNOUNCE: dbus 0.10
On 06/23/2012 09:10 PM, John Millikin wrote: This is completing the merger of the dbus-core and dbus-client packages. The new package does everything they can do, but better. Hackage: http://hackage.haskell.org/package/dbus Homepage: https://john-millikin.com/software/haskell-dbus/ API reference: https://john-millikin.com/software/haskell-dbus/reference/haskell-dbus/0.10/ Examples: Included in the tarball, and also at https://john-millikin.com/branches/haskell-dbus/0.10/head:/examples/ Notable changes: * The module hierarchy was simplified. Most users will only ever need the DBus and DBus.Client modules. * Exports which were not used or useful have been removed. * Much better documentation -- most exports now have a description, and several have examples. * The source code isn't literate any more. Too many people expressed frustration at trying to contribute, so I just converted it all to standard flat .hs files. * Better support for custom socket transports and authentication mechanisms. * Added support for listening for socket connections. This allows users to implement both sides of a peer-peer session. * Various improvements to performance, including moving from binary to cereal. * Various minor improvements to correctness. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe Great that you finally did that. Because recently it was hard to understand that dbus-client is merged into dbus-core-0.9 without some haskell-cafe log. -- Best regards, dmitry malikov ! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Unambiguous choice implementation
I'm reading Conal Elliot's paper, Push-Pull FRP. At some point he needs an unambiguous choice operator, essentially to implement select: a future that waits for one of its future arguments to fire. His implementation of unamb creates two threads racing on a shared MVar. By his own admission, this is very inefficient. My question is, is there a better implementation? -- [:Bartosz:] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] cvs-ghc mailing list silently dropping my mails
Hi all, I've been trying to send mail to the cvs-ghc mailng list and the list seems to be silently dropping my emails. I have: a) Made sure I was sending mail with the subscribed from address. b) Unsubscribed and re-subscribed and tried again. All to no avail. Is there a moderation queue on that list that needs to be seen to? Cheers, Erik -- -- Erik de Castro Lopo http://www.mega-nerd.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Martin Odersky on What's wrong with Monads
Cafe, I was watching a panel on languages[0] recently and Martin Odersky (the creator of Scala) said something about Monads: What's wrong with Monads is that if you go into a Monad you have to change your whole syntax from scratch. Every single line of your program changes if you get it in or out of a Monad. They're not polymorphic so it's really the old days of Pascal. A monomorphic type system that says 'well that's all I do' ... there's no way to abstract over things. [0, 53:45] Thoughts? --J Arthur [0] - http://css.dzone.com/articles/you-can-write-large-programs ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
