- Libraries - Haskell.org

Dear friends from haskell
by foxseo2023 24 Nov '23

24 Nov '23

Dear friends from I hope this message finds you well and thriving in your endeavors. As a fellow Vietnamese student currently pursuing education in the United States, I can't help but feel a sense of pride and excitement about the prospect of inviting you to experience the beauty and charm of my homeland, Vietnam. Vietnam is a land of captivating landscapes, rich history, and warm hospitality. From the breathtaking Ha Long Bay with its emerald waters and limestone karsts to the vibrant city life of Ho Chi Minh City, our country offers a diverse range of experiences for every traveler. Picture yourself exploring the ancient town of Hoi An, with its lantern-lit streets and traditional architecture, or hiking through the terraced rice fields of Sapa, surrounded by lush greenery. Beyond the scenic landscapes, you will discover the heart and soul of Vietnam in its people. The kindness and friendliness of the Vietnamese people create an atmosphere of warmth that is truly unique. Whether you're savoring the delicious street food in Hanoi, engaging in conversations with locals, or witnessing the traditional water puppetry shows, you'll find yourself immersed in a culture that values community and connection. Vietnam is not just a destination; it's an experience that will leave a lasting impression on your heart. I extend this invitation to you with the hope that you'll consider making Vietnam your next travel destination. Come and discover the hidden gems, the delectable cuisine, and the genuine smiles that await you in the heart of Southeast Asia. I look forward to the day when I can share the beauty of my homeland with you in person. Until then, safe travels and may your curiosity lead you to the wonders of Vietnam. Best regardshttps://vking.vn/kien-truc/biet-thu-tan-co-dien/

1 0

maintenance of the "cond" package
by James Cranch 11 Oct '23

11 Oct '23

I have been trying to contact the maintainer of the package cond: https://hackage.haskell.org/package/cond I am interested in development, and I submitted a pull request three weeks ago. I emailed the listed address for the maintainer to follow up on that pull request, but my email bounced as undeliverable. Searching the web suggested an alternative address (which, since it is not the official address listed for the maintainer, I am BCCing rather than CCing), but an email I sent to that address has gone without reply for ten days. It does appear that the maintainer has recently been active on github, however. I'm very happy to work with the maintainer as they prefer, but this email is a statement of my intent to take over (if necessary) the maintenance of the package according to this procedure: https://wiki.haskell.org/Taking_over_a_package Of course this will be reversible.

1 0

[ANN] BNFC 2.9.5 released
by Andreas Abel 26 Jul '23

26 Jul '23

BNFC 2.9.5 is available at - https://hackage.haskell.org/package/BNFC-2.9.5 - https://github.com/BNFC/bnfc/releases/tag/v2.9.5 (binaries and changelog) Feedback welcome, problems at https://github.com/BNFC/bnfc/issues . The BNF Converter (bnfc) is a wizard generating syntax trees, parser and printer from a Labelled BNF (LBNF) grammar. It is currently able to generate Haskell, Agda, C, C++, Java, and OCaml representations. Supported parser generators: Happy, ocamlyacc, Menhir, ANTLR, CUP, Bison. More information: http://bnfc.digitalgrammars.com Changes in 2.9.5: * C/C++/Java: escape newline etc. when printing `String` and `Char` literals [[#449](https://github.com/BNFC/bnfc/issues/449)] * Java/ANTLR: unescape `String` and `Char` literals in parser (needs Java ≥ 15) [[#451](https://github.com/BNFC/bnfc/issues/451)] * Java/ANTLR: fix case problem with language names like `C` [[#455](https://github.com/BNFC/bnfc/issues/455)] * Java with line numbers: compatibility with `jflex` ≥ 1.8 [[#453](https://github.com/BNFC/bnfc/issues/453)] * Haskell/GADT: generated `ComposOp.hs` no longer needs `mtl` library [[#438](https://github.com/BNFC/bnfc/pull/438)] * Ocaml: fixed a crash in printer with unbalanced `}` [[#439](https://github.com/BNFC/bnfc/issues/439)] * Ocaml: lex escape sequences in `Char` [[#452](https://github.com/BNFC/bnfc/issues/452)] * Ocaml: removed superfluous `let rec` in the printers for token categories Cheers, Andreas -- Andreas Abel <>< Du bist der geliebte Mensch. Department of Computer Science and Engineering Chalmers and Gothenburg University, Sweden andreas.abel(a)gu.se http://www.cse.chalmers.se/~abela/

1 0

[ANN] bytestring-0.11.5.0 and bytestring-0.12.0.0
by Matthew Craven 07 Jul '23

07 Jul '23

On behalf of the maintainers team I'm happy to announce that two new bytestring versions have been released: * bytestring-0.11.5.0 is expected to be the last release in the bytestring-0.11 series. * bytestring-0.12.0.0 bundles all of the planned breaking changes that have been in the pipeline for the last few years. Highlights from the changelog (https://github.com/haskell/bytestring/blob/0.12.0.0/Changelog.md) * Some recently-discovered bugs in the SIMD implementations of isValidUtf8 have been fixed. * With bytestring-0.12.0.0, ShortByteString can now be safely coerced to or from the ByteArray type. * Many functions returning StrictByteString can now return their results unboxed. Many people contributed their time and effort to make this release happen. Thanks to all of them! Just to name a few, in no particular order: * Viktor Dukhovni * Vaibhav Sagar * Simon Jakobi * Matthew Craven * Andrew Lelechenko * Sergey Vinokurov * Koz Ross * Every contributor to past bytestring releases Happy Haskelling! ~-Matthew Craven

1 0

Proposal: add laws to MonadError
by Alexandre Esteves 06 Jul '23

06 Jul '23

I ran into a scenario where the use of MonadError would only be valid if catchError (pure a) h = pure a was a law, so I looked up the laws in https://hackage.haskell.org/package/mtl-2.3/docs/Control-Monad-Error-Class.… but surprisingly found none. One would expect to see 1. catchError (pure a) h = pure a 2. catchError (throwError e) h = h e 3. throwError e >>= f = throwError e which would rule out silly instances like instance MonadError () Maybe where throwError () = Nothing catchError _ f = f () Searching for "monad error laws" gives me no haskell results, only https://typelevel.org/blog/2018/04/13/rethinking-monaderror.html which suggests the same laws. I propose adding these 3 laws to MonadError haddocks. AFAICT the IO/Maybe/Either/ExceptT instances in https://hackage.haskell.org/package/mtl-2.3/docs/src/Control.Monad.Error.Cl… all obey the laws.

3 7

Help with package/module naming
by David Feuer 09 May '23

09 May '23

I'm currently putting the finishing touches on the first version of a new priority queue package. It implements amortized-optimal priority queues and is intended to compete with the heaps package with a simpler, more compact, and hopefully faster implementation†. The main types are key-only and key-value priority queues, which I'm naming based on the conventions of the pqueue package: data MinQueue k data MinPQueue k a data MaxQueue k data MaxPQueue k a Additionally, the implementation uses underlying types with constant time insertion, logarithmic-time union, logarithmic time peekMin, and logarithmic time deleteMin: -- Key-value priority queues that are strict in both the key and the -- value. data MinPQueue k a -- Similar to the above, but associating -- two values with each key. The @a@ -- value is stored strictly and the @b@ value -- is stored lazily. data MinPQueue2 k a b So I have a few questions: 1. What should I name this package? 2. What should I name the modules containing the bootstrapped queues? 3. What should I name the modules containing the underlying oddly-strict queues? I don't know how many people will want to use them, but I figure they're probably just what's needed from time to time and it's better to let them loose than keep them under wraps. Finally, there is the question of how to expose internals. In addition to the queues above, with are all reasonable things for public consumption, there are modules implementing those, as well as a couple modules implementing helper types and such. I'm really no good at figuring out how to "lay out" modules in a package, so any advice would be greatly appreciated. † The heaps package uses bootstrapped skew binomial heaps (Brodal and Okasaki), achieving worst case constant-time union and peekMin and worst case logarithmic time deleteMin. The package I'm working on uses the same bootstrapping technique, but with a space-saving modification of Louis Wasserman's realization of Okasaki lazy binomial heap as the base priority queue. It achieves the same bounds, but union is only constant time in the (persistently) amortized sense; it degrades to logarithmic time in the worst case. In practice, this theoretical degradation likely doesn't matter, both because it's small and because GHC's garbage collection imposes occasional delays regardless.

1 0

test-framework-quickcheck2 maintainers
by Ben Franksen 20 Apr '23

20 Apr '23

I have made a PR and hackage says the maintainers are libraries(a)haskell.org. Could someone take a look, please? Cheers, Ben -- I would rather have questions that cannot be answered, than answers that cannot be questioned. -- Richard Feynman

1 0

Intend to take over package filelock
by Andreas Abel 23 Mar '23

23 Mar '23

See https://discourse.haskell.org/t/take-over-filelock-package/6037?u=andreasab… : I intend to take over https://hackage.haskell.org/package/filelock. It is a dependency of crucial Haskell infrastructure such as `pantry` and `haskell-server` (via `acid-state`). I needs a fix to work with `unix-2.8` as released with GHC 9.6: - https://github.com/takano-akio/filelock/pull/13 I have been trying to communicate this on github to the maintainer Takano Akio since 2023-02-08. I have tried to contact the maintainer by email 2023-03-12, but have gotten no response. Preferably, the maintainer would come back, but I do not have much hope, their last public github activity was 2021-08-22. -- Andreas Abel <>< Du bist der geliebte Mensch. Department of Computer Science and Engineering Chalmers and Gothenburg University, Sweden andreas.abel(a)gu.se http://www.cse.chalmers.se/~abela/

1 0

Re: whither the maintainer for comp-data? request for NMU?
by Carter Schonwald 13 Mar '23

13 Mar '23

welcome back! ;) On Mon, Mar 13, 2023 at 4:12 AM Patrick Bahr <paba(a)itu.dk> wrote: > Andreas, Carter, > > Apologies for neglecting my maintainer duties on comp-data. I will catch > up on it this week. > > I'd happily accept a co-maintainer, but I don't have any candidate. > > -- Patrick > > ________________________________________ > From: Carter Schonwald <carter.schonwald(a)gmail.com> > Sent: 01 March 2023 00:32 > To: Andreas Abel > Cc: Haskell Libraries; Patrick Bahr; patrick(a)bahr.io > Subject: Re: whither the maintainer for comp-data? request for NMU? > > Andreas: thanks for ccing Patrick! > > At the very least, data comp is an amazing exploration of pushing data > type a la carte style engineering to its limits and keeping it buildable > seems valuable > > Happily the main issue seems to be a matter of migrating some template > Haskell > > On Tue, Feb 28, 2023 at 11:59 AM Andreas Abel <andreas.abel(a)ifi.lmu.de > <mailto:andreas.abel@ifi.lmu.de>> wrote: > Patrick, maybe you would accept a co-maintainer for comp-data? > > But then, there should also be a co-maintainer wanting to take the job... > > Concerning NMUs, there is info here: > > https://github.com/haskell-infra/hackage-trustees/blob/master/policy.md#3-s… > > On 2023-01-23 19:37, Carter Schonwald wrote: > > Hey everyone, > > https://github.com/pa-ba/compdata/issues/36 > > <https://github.com/pa-ba/compdata/issues/36> and many similar issues > > and 1-3 corresponding PRs have been posted to the comp-data repo, whats > > the current process for engaging the trustees in making an NMU that > > handles newer ghc support? (these issues have been standing for ~ a year > > now). > > > > ideally the maintainer surfaces in the near future, but would be great > > to get it buildable again > > > > -Carter >

1 0

whither the maintainer for comp-data? request for NMU?
by Carter Schonwald 28 Feb '23

28 Feb '23

Hey everyone, https://github.com/pa-ba/compdata/issues/36 and many similar issues and 1-3 corresponding PRs have been posted to the comp-data repo, whats the current process for engaging the trustees in making an NMU that handles newer ghc support? (these issues have been standing for ~ a year now). ideally the maintainer surfaces in the near future, but would be great to get it buildable again -Carter

2 2