News aggregator

Final CFP: WPTE 2015 Second International Workshop on Rewriting Techniques for Program Transformations and Evaluation

General haskell list - Thu, 04/09/2015 - 8:23am
FINAL CALL FOR PAPERS Second International Workshop on Rewriting Techniques for Program Transformations and Evaluation WPTE 2015 affiliated with RDP 2015 2 July, 2015, Warsaw, Poland Aims and Scope ============== The aim of WPTE is to bring together the researchers working on program transformations, evaluation, and operationally-based programming language semantics, using rewriting methods, in order to share the techniques and recent developments and to exchange ideas to encourage further activation of research in this area. The previous WPTE was held in Vienna 2014. Topics of interest in the scope of this workshop include: * Correctness of program transformations, optimizations and translations. * Program transformations for proving termination, confluence and
Categories: Incoming News

PrimMonad for Control.Monad.ST.Lazy?

haskell-cafe - Thu, 04/09/2015 - 3:49am
I notice that the strict ST monad has an instance for PrimMonad but the lazy ST monad does not. Is there a reason why, or is merely an oversight? (What I Am Really Trying To Do: get a purely lazy stream of random values out of mwc-random.) --ken _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >
Categories: Offsite Discussion

Why are we naming types instead of instances when we have multiple instances per type?

Haskell on Reddit - Thu, 04/09/2015 - 3:19am

Hey this always struck me as odd. Why do we newtype types to use different istances where it would make a lot more sense to name the instance instead? We seem to be naming the wrong thing.

submitted by arianvp
[link] [38 comments]
Categories: Incoming News

Giving up on NixOS (for now)

Haskell on Reddit - Thu, 04/09/2015 - 3:04am
Categories: Incoming News

Generalized Newtype Deriving not allowed in SafeHaskell

haskell-cafe - Thu, 04/09/2015 - 2:43am
When compiling code with Generalized Newtype Deriving and the -fwarn-unsafe flag, I get -XGeneralizedNewtypeDeriving is not allowed in Safe Haskell This happens both in GHC 7.8 and GHC 7.10. I thought I remembered reading somewhere that GNTD is now part of the safe language? The GHC manual used to state that GNTD is not allowed in Safe Haskell: But this language on GNTD not being part of the safe language was removed in the 7.8 manual: The GHC release notes don't say anything about this one way or the other. Thoughts? _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >
Categories: Offsite Discussion

Last CFP Bx'15: 4th International Workshop onBidirectional Transformations

General haskell list - Wed, 04/08/2015 - 5:06pm
LAST CALL FOR PAPERS Fourth International Workshop on Bidirectional Transformations (Bx 2015) L'Aquila, Italy (co-located with STAF, July 24, 2015) Bidirectional transformations (Bx) are a mechanism for maintaining the consistency of at least two related sources of information. Such sources can be relational databases, software models and code, or any other document following standard or ad-hoc formats. Bx are an emerging topic in a wide range of research areas, with prominent presence at top conferences in several different fields (namely databases, programming languages, software engineering, and graph transformation), but with results in one field often getting limited exposure in the others. Bx 2015 is a dedicated venue for Bx in all relevant fields, and is part of a workshop series that was created in order to promote cross-disciplinary research and awareness in the area. A
Categories: Incoming News

skip hpc during build

glasgow-user - Mon, 04/06/2015 - 3:35pm
I'm deleting hpc after building ghc for a vm to save space. Is there an easy way to skip building it in the first place? -- View this message in context: Sent from the Haskell - Glasgow-haskell-users mailing list archive at
Categories: Offsite Discussion

runghc and GhcWithInterpreter

glasgow-user - Mon, 04/06/2015 - 3:34pm
I've built GHC with GhcWithInterpreter = NO. runghc is built and installed, but errors out with "not built for interactive use". Is runghc supposed to work with such a build? If not, why is it built at all? -- View this message in context: Sent from the Haskell - Glasgow-haskell-users mailing list archive at
Categories: Offsite Discussion

Proposal for a generic showIntAtBase

libraries list - Sun, 04/05/2015 - 5:46pm
Hi, The current implementation of showIntAtBase in Numeric is limited to Chars currently. *showIntAtBase* * :: (Integral a, Show a) => a -> (Int -> Char) -> a -> ShowS* The 2 reasons for this constraint is: a) We only accept functions of the form (Int -> Char) b) An implicit concatenation using (:) I'd like to propose a new function showIntAtBaseGeneric that removes the (Int -> Char) function constraint and takes an additional function to replace the implicit (:) operator. *showIntAtBaseGeneric* * :: (Integral a1, Num b, Show a1) =>* * a1 -> (b -> a) -> (a -> s -> s) -> a1 -> s -> s* Now showIntAtBase may be implemented as: *showIntAtBase :: (Integral a, Show a) => a -> (Int -> Char) -> a -> ShowS* *showIntAtBase base toChr n0 r0 = showIntAtBaseGeneric base toChr (:) n0 r0* The API and behavior of showIntAtBase remains unchanged while allowing for generic conversions not limited to Chars alone. *Example: * *λ> showIntAtBaseGeneric 26 id (:) 500 [] -- convert 500 to base26 and provid
Categories: Offsite Discussion

A Random Strawman

libraries list - Sat, 04/04/2015 - 6:57pm
Hello All, Having skimmed the literature, run some tests and benchmarks: The current System.Random is broken: Furthermore, this is recorded in at least two published papers: and The tf-random package does not have this breakage and is based on good theoretical foundations. In my tests tf-random performs better than System.Random. As a result of which, I am very much inclined to suggest we replace the code in System.Random with tf-random. Before doing any more work on this, I’d like to understand what the next steps should be. How much review should be carried out? I have no reason to doubt the implementors have done a great job but should someone (who?) review the code more formally. If so what would the process / tools be? Tests in packages / applications may now fail as the (pseudo) random numbers will be different w
Categories: Offsite Discussion

immortal profiling

glasgow-user - Fri, 04/03/2015 - 6:05am Would be really useful to be able to profile code without dying, especially in the context of a long-lived server. Am I missing something that would allow me to do this? cheers mark _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users< at >
Categories: Offsite Discussion

New gtk2hs 0.12.4 release

gtk2hs - Wed, 11/21/2012 - 12:56pm

Thanks to John Lato and Duncan Coutts for the latest bugfix release! The latest packages should be buildable on GHC 7.6, and the cairo package should behave a bit nicer in ghci on Windows. Thanks to all!


Categories: Incoming News