- Haskell-Cafe - Haskell.org

ANN: prefix-units 0.2.0
by Iustin Pop 22 Nov '15

22 Nov '15

Hi all, New version of my small library prefix-units (for parsing and formatting things like "10K"). Changes: * Incompatible API change to cleanup some initial design decisions: the two level `FormatOption`/`FormatMode` model is removed, the fixed unit of `FormatOption` is moved to a new constructor `FormatMode`, and `FormatOption` is removed entirely. This should be a simpler API, at the cost of breaking compatibility. * Fixed issue #3 (No support for negative numbers). * Worked around issue #1 (Add 'base' unit) by adding a mode that disables scaling; it should have the same effect without introducing an artificial unit. Feedback welcome, either via email or at https://github.com/iustin/prefix-units. happy hacking, iustin

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Warning: Tab Character
by Jeon-Young Kang 21 Nov '15

21 Nov '15

Hello everyone. I am a newbie of Haskell, using Textmate on mac. I got the following warning. How can I fix it? Warning: Tab character Ok, modules loaded: Main. Sincerely, Young

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NNOUNCE: Haskell Communities and Activities Report (29th ed., November 2015)
by Mihai Maruseac 21 Nov '15

21 Nov '15

On behalf of all the contributors, we are pleased to announce that the Haskell Communities and Activities Report (29th edition, November 2015) is now available, in PDF and HTML formats: http://haskell.org/communities/11-2015/report.pdf http://haskell.org/communities/11-2015/html/report.html Many thanks go to all the people that contributed to this report, both directly, by sending in descriptions, and indirectly, by doing all the interesting things that are reported. We hope you will find it as interesting a read as we did. If you have not encountered the Haskell Communities and Activities Reports before, you may like to know that the first of these reports was published in November 2001. Their goal is to improve the communication between the increasingly diverse groups, projects, and individuals working on, with, or inspired by Haskell. The idea behind these reports is simple: Every six months, a call goes out to all of you enjoying Haskell to contribute brief summaries of your own area of work. Many of you respond (eagerly, unprompted, and sometimes in time for the actual deadline) to the call. The editors collect all the contributions into a single report and feed that back to the community. When we try for the next update, six months from now, you might want to report on your own work, project, research area or group as well. So, please put the following into your diaries now: ======================================== End of March 2015: target deadline for contributions to the May 2015 edition of the HCAR Report ======================================== Unfortunately, many Haskellers working on interesting projects are so busy with their work that they seem to have lost the time to follow the Haskell related mailing lists and newsgroups, and have trouble even finding time to report on their work. If you are a member, user or friend of a project so burdened, please find someone willing to make time to report and ask them to "register" with the editors for a simple e-mail reminder in March (you could point us to them as well, and we can then politely ask if they want to contribute, but it might work better if you do the initial asking). Of course, they will still have to find the ten to fifteen minutes to draw up their report, but maybe we can increase our coverage of all that is going on in the community. Feel free to circulate this announcement further in order to reach people who might otherwise not see it. Enjoy! Mihai Maruseac <hcar at haskell.org> -- Mihai Maruseac (MM) "If you can't solve a problem, then there's an easier problem you can solve: find it." -- George Polya

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RDF with Haskell
by Jeon-Young Kang 21 Nov '15

21 Nov '15

I am a newbie learning Haskell. I'd like to import RDF in Haskell as well as to do SPARQL. I went through RDF4H, Swish, and so on. But it is still difficult to understand them for me. Anyone can suggest me to learn that? or recommend any kinds of books or tutorials? Sincerely, Jeon-Young -- Department of Geography State University of New York at Buffalo jykang22(a)gmail.com Jeon-Young Kang

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Re: [Haskell-cafe] AMP - how do you motivate this in teaching?
by Olaf Klinke 21 Nov '15

21 Nov '15

Albert's explanation is the best so far, IMHO. liftA2 is by far the most useful and reasonable function in Control.Applicative. Realizing that it can be made the definition of Applicative is what made me friends with that typeclass. As an algebraicist, to me Control.Monad.join is what distinguishes Monad from Applicative, although Albert's explanation is more accessible new programmers. I tend to explain monads by example of container monads mimicking powerset features, and join has a natural interpretation there. -- Olaf

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ANN: cacophony 0.4.0, pipes-cacophony 0.1.2
by John Galt 20 Nov '15

20 Nov '15

cacophony[1] is a library which implements the Noise[2] protocol. Noise is a framework for cryptographic protocols based on ECDH key agreement authored by Trevor Perrin. pipes-cacophony[3] builds on cacophony to provide pipes that facilitate key agreement and secure messaging (in conjunction with, for example, pipes-network). -- John [1] http://hackage.haskell.org/package/cacophony [2] https://github.com/trevp/noise/blob/master/noise.md [3] http://hackage.haskell.org/package/pipes-cacophony

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AMP - how do you motivate this in teaching?
by Johannes Waldmann 20 Nov '15

20 Nov '15

Because of AMP, I have to rewrite slides and example code for my lectures, and I don't like it. In fact I probably won't do it, and will advise students to return to ghc-7.8 - but then, how does that look? Really, my answer to [1] 3.5 Beginner friendliness How often did you say ... "A Monad is always an Applicative" is: never. (for "is a Functor" - often. In fact, always) Now, I don't want to bring on another general discussion of AMP - instead I'd like to hear from people who use monads in teaching (e.g., to define semantic domains) about how they sell "Applicative m =>" to their students. (The intersection of AMPers and teachers is non-empty?) - Johannes [1] https://wiki.haskell.org/Functor-Applicative-Monad_Proposal

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Re: [Haskell-cafe] [Coq-Club] ANN: linearscan, linearscan-hoopl 1.0.0
by John Wiegley 20 Nov '15

20 Nov '15

>>>>> Beta Ziliani <bziliani(a)famaf.unc.edu.ar> writes: > I'd be interested to know what was the outcome of the project from the point > of view of BEA Systems. Is there any report about it? >From BAE's point of view, we gained some industrial perspective. Separately, I have prepared an experience report that is currently seeking a venue. John

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ANN: stack-0.1.8.0
by Emanuel Borsboom 20 Nov '15

20 Nov '15

New version released of Stack, a build tool. See README <https://github.com/commercialhaskell/stack/tree/release#how-to-install> for installation and upgrade instructions. There are now Windows installers available: download them here <https://github.com/commercialhaskell/stack/blob/release/doc/install_and_upg…>. In addition, new Fedora 23 packages are available here <https://github.com/commercialhaskell/stack/blob/release/doc/install_and_upg…> . Note that, starting with v0.1.8.0, releases of Stack will always have an even-numbered second-to-last version component. Odd second-to-last version components are reserved for unstable builds. Major changes: - GHCJS can now be used with stackage snapshots via the new compiler field. - Docker integration works with non-FP Complete generated images #531 <https://github.com/commercialhaskell/stack/issues/531> Other enhancements: - Added an allow-newer config option #922 <https://github.com/commercialhaskell/stack/issues/922> #770 <https://github.com/commercialhaskell/stack/issues/770> - When a Hackage revision invalidates a build plan in a snapshot, trust the snapshot #770 <https://github.com/commercialhaskell/stack/issues/770> - Added a stack config set resolver RESOLVER command. Part of work on #115 <https://github.com/commercialhaskell/stack/issues/115> - stack setup can now install GHCJS on windows. See #1145 <https://github.com/commercialhaskell/stack/issues/1145> and #749 <https://github.com/commercialhaskell/stack/issues/749> - stack hpc report command added, which generates reports for HPC tix files - stack ghci now accepts all the flags accepted by stack build. See #1186 <https://github.com/commercialhaskell/stack/issues/1186> - stack ghci builds the project before launching GHCi. If the build fails, optimistically launch GHCi anyway. Use stack ghci --no-build option to disable #1065 <https://github.com/commercialhaskell/stack/issues/1065> - stack ghci now detects and warns about various circumstances where it is liable to fail. See #1270 <https://github.com/commercialhaskell/stack/issues/1270> - Added require-docker-version configuration option - Packages will now usually be built along with their tests and benchmarks. See #1166 <https://github.com/commercialhaskell/stack/issues/1166> - Relative local-bin-path paths will be relative to the project’s root directory, not the current working directory. #1340 <https://github.com/commercialhaskell/stack/issues/1340> - stack clean now takes an optional [PACKAGE] argument for use in multi-package projects. See #583 <https://github.com/commercialhaskell/stack/issues/583> - Ignore cabal_macros.h as a dependency #1195 <https://github.com/commercialhaskell/stack/issues/1195> - Pad timestamps and show local time in —verbose output #1226 <https://github.com/commercialhaskell/stack/issues/1226> - GHCi: Import all modules after loading them #995 <https://github.com/commercialhaskell/stack/issues/995> - Add subcommand aliases: repl for ghci, and runhaskell for runghc #1241 <https://github.com/commercialhaskell/stack/issues/1241> - Add typo recommendations for unknown package identifiers #158 <https://github.com/commercialhaskell/stack/issues/158> - Add stack path --local-hpc-root option - Overhaul dependencies’ haddocks copying #1231 <https://github.com/commercialhaskell/stack/issues/1231> - Support for extra-package-dbs in ‘stack ghci’ #1229 <https://github.com/commercialhaskell/stack/pull/1229> - stack new disallows package names with “words” consisting solely of numbers #1336 <https://github.com/commercialhaskell/stack/issues/1336> - stack build --fast turns off optimizations Bug fixes: - Fix: Haddocks not copied for dependencies #1105 <https://github.com/commercialhaskell/stack/issues/1105> - Fix: Global options did not work consistently after subcommand #519 <https://github.com/commercialhaskell/stack/issues/519> - Fix: ‘stack ghci’ doesn’t notice that a module got deleted #1180 <https://github.com/commercialhaskell/stack/issues/1180> - Rebuild when cabal file is changed - Fix: Paths in GHC warnings not canonicalized, nor those for packages in subdirectories or outside the project root #1259 <https://github.com/commercialhaskell/stack/issues/1259> - Fix: unlisted files in tests and benchmarks trigger extraneous second build #838 <https://github.com/commercialhaskell/stack/issues/838>

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On Hiatus Until January 2016: Haskell Weekly News
by Kim-Ee Yeoh 20 Nov '15

20 Nov '15

Regrettably, I must announce that Haskell Weekly News will go on hiatus until the new year. I recognize that the last issue was back in September. It's been said that "The more a man possesses over and above what he uses, the more careworn he becomes." In my case, mundane possessions have indeed insisted on being attended to. I wish every reader a fine holiday season. -- Kim-Ee Editor of Haskell Weekly News

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