Re: [Haskell-cafe] Question about Newtype op() function arguments.
Ah, so is the idea, then, to use *op()* when `n` wasn't actually constructed formally, but rather assembled by the user, so as to match the type of the accessor function normally supplied as the argument to the constructor? 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
[Haskell-cafe] Examples of MVars usage
Hello, everyone. I am looking for packages on hackage which use MVars extensively. Those which create plenty of MVars -- not just one or two for conditional synchronization or to keep track of a value throughout the program. My purpose is to analyze usage patterns of MVars. Does anybody have any suggestions? So far I have analyzed a few packages: * conjure (0.1) * distributed-process (0.4.2) * distributed-process-p2p (0.1.1.0) * leksah (0.12.1.3) * manatee-core (0.1.1) * urlcheck (0.1.1) Nonetheless, I feel like I still haven't covered a good enough range of usage, since some examples are small, and some use MVars just for a small number of cases, while the heavy lifting is done with STM. And surely because there are only 6 of them. Any suggestion will be very much appreciated. []'s -- Francisco Soares Nt. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Examples of MVars usage
Hi Francisco, You can try GitHub's code search https://github.com/search?l=Haskellq=mvarref=cmdformtype=Code Cheers, --Lucas 2013/6/12 Francisco M. Soares Nt. xfrancisco.soa...@gmail.com Hello, everyone. I am looking for packages on hackage which use MVars extensively. Those which create plenty of MVars -- not just one or two for conditional synchronization or to keep track of a value throughout the program. My purpose is to analyze usage patterns of MVars. Does anybody have any suggestions? So far I have analyzed a few packages: * conjure (0.1) * distributed-process (0.4.2) * distributed-process-p2p (0.1.1.0) * leksah (0.12.1.3) * manatee-core (0.1.1) * urlcheck (0.1.1) Nonetheless, I feel like I still haven't covered a good enough range of usage, since some examples are small, and some use MVars just for a small number of cases, while the heavy lifting is done with STM. And surely because there are only 6 of them. Any suggestion will be very much appreciated. []'s -- Francisco Soares Nt. ___ 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] Examples of MVars usage
On 12 June 2013 21:29, Francisco M. Soares Nt. xfrancisco.soa...@gmail.com wrote: I am looking for packages on hackage which use MVars extensively. Those which create plenty of MVars Hi Francisco, Also take a look at Control.Concurrent.Chan in the base library: http://hackage.haskell.org/packages/archive/base/latest/doc/html/Control-Concurrent-Chan.html A big Chan has a lot of MVars inside. Bas ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Haskell Weekly News: Issue 270
Welcome to issue 270 of the HWN, an issue covering crowd-sourced bits of information about Haskell from around the web. This issue covers the week of June 2 to 8, 2013. Quotes of the Week * shachaf: getLine :: IO String contains a String in the same way /bin/ls contains a list of files. Top Reddit Stories * Haskell's HLearn library cross-validates more than 400x faster than Java's Weka due to new monoid based algorithm Domain: izbicki.me, Score: 86, Comments: 13 On Reddit: [1] http://goo.gl/dAoe5 Original: [2] http://goo.gl/dLZJv * FP Complete Launches Haskell in Real World Competition with $1,000 Cash Prize Each Month Domain: fpcomplete.com, Score: 80, Comments: 10 On Reddit: [3] http://goo.gl/FthPX Original: [4] http://goo.gl/pzgQ2 * So I write compilers for a living now Domain: evincarofautumn.blogspot.it, Score: 76, Comments: 69 On Reddit: [5] http://goo.gl/hXp0G Original: [6] http://goo.gl/wMaab * Haskell for all: pipes-parse-1.0.0: Pushback, delimited parsers, resumable parsing, and lenses Domain: haskellforall.com, Score: 55, Comments: 77 On Reddit: [7] http://goo.gl/U3MzG Original: [8] http://goo.gl/3wEJ7 * Thank you to the Haskell community for encouraging programmers to explore the relationship between algebra and programming. -- My accepted paper at the International Conference of Machine Learning (ICML13) Domain: jmlr.org, Score: 54, Comments: 3 On Reddit: [9] http://goo.gl/Ni0oF Original: [10] http://goo.gl/klOzM * GHCJS introduction – Concurrent Haskell in the browser, by Luite Stegeman Domain: weblog.luite.com, Score: 54, Comments: 27 On Reddit: [11] http://goo.gl/l9LDH Original: [12] http://goo.gl/avaez * Haskell from C: Where are the for Loops? Domain: fpcomplete.com, Score: 46, Comments: 28 On Reddit: [13] http://goo.gl/YqkSU Original: [14] http://goo.gl/pwYB3 * fficxx - FFI to C++ in Haskell Domain: ianwookim.org, Score: 45, Comments: 12 On Reddit: [15] http://goo.gl/y1awM Original: [16] http://goo.gl/wHF2U * Control.Category: now with kind polymorphism Domain: neocontra.blogspot.com, Score: 42, Comments: 7 On Reddit: [17] http://goo.gl/9gb6f Original: [18] http://goo.gl/ALvld * Pixel art editor in 600 lines of Haskell Domain: github.com, Score: 39, Comments: 5 On Reddit: [19] http://goo.gl/gmFOF Original: [20] http://goo.gl/w8yEg * Haskell for all: pipes-concurrency-1.2.0: Behaviors and broadcasts Domain: haskellforall.com, Score: 35, Comments: 35 On Reddit: [21] http://goo.gl/rojk1 Original: [22] http://goo.gl/aNK8l * Mastermind in Agda, Running in the Browser Domain: people.inf.elte.hu, Score: 28, Comments: 0 On Reddit: [23] http://goo.gl/N8yty Original: [24] http://goo.gl/7lhvT * Bittoll: A bitcoin transaction system written in Haskell. Domain: bittoll.com, Score: 25, Comments: 13 On Reddit: [25] http://goo.gl/9MFXB Original: [26] http://goo.gl/q39ps * standalone-haddock: host your Haskell documentation on your website Domain: feuerbach.github.io, Score: 22, Comments: 7 On Reddit: [27] http://goo.gl/dAsmP Original: [28] http://goo.gl/INyIe Top StackOverflow Questions * What is () in Haskell, exactly? votes: 18, answers: 4 Read on SO: [29] http://goo.gl/XkrXD * Haskell pre-monadic I/O votes: 15, answers: 1 Read on SO: [30] http://goo.gl/oryYA * Display function types in Haskell votes: 12, answers: 1 Read on SO: [31] http://goo.gl/qOtpV * Haskell Pattern Matching Fails on Negative Number votes: 12, answers: 2 Read on SO: [32] http://goo.gl/mw4WF * Debugging performance bottlenecks for longest common subsequence algorithm votes: 11, answers: 1 Read on SO: [33] http://goo.gl/mfa8S * What is a shrink, with regard to Haskell's QuickCheck? votes: 11, answers: 2 Read on SO: [34] http://goo.gl/eLlyO * Cross module optimizations in GHC votes: 10, answers: 1 Read on SO: [35] http://goo.gl/RyFQP * Functional composition with multi-valued functions in haskell? votes: 9, answers: 3 Read on SO: [36] http://goo.gl/10Xvd * A more succinct way to map functions onto fields of an algebraic datatype? votes: 9, answers: 1 Read on SO: [37] http://goo.gl/CfIOa * What's the history behind the Functor type class? votes: 8, answers: 1 Read on SO: [38] http://goo.gl/5BwZS Until next time, [39]+Daniel Santa Cruz References 1. http://izbicki.me/blog/hlearn-cross-validates-400x-faster-than-weka 2. http://www.reddit.com/r/haskell/comments/1fl33k/haskells_hlearn_library_crossvalidates_more_than/ 3. http://www.fpcomplete.com/blog/2013/06/call-for-submissions 4. http://www.reddit.com/r/haskell/comments/1fvtbf/fp_complete_launches_haskell_in_real_world/ 5.
[Haskell-cafe] Nightly builds of GHC HEAD for OS X 10.8
Since mid-January, I’ve been running nightly builds of GHC on my Mac Pro for 10.8.x, 64-bit. I’ve decided to make these results publically downloadable here: http://ghc.newartisans.com. The installer tarballs are in dist, while the fulltest and nofib logs are in logs. According to Jenkins this build takes 8h15m minutes, so I figured this might save others some CPU heat. -- John Wiegley FP Complete Haskell tools, training and consulting http://fpcomplete.com johnw on #haskell/irc.freenode.net ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Testing invasive proposals with Hackager
In many discussions we make guesses about how much code proposals like Functor = Monad would break. You can use https://github.com/dterei/Hackager to build all of Hackage (preferably in a VM). Of course many packages have external dependencies, so I'd like to share the following list of packages to save you some time. (These are the names of packages suited for a Ubuntu 13.04 VM, and with these installed, 2800 packages are successfully built and 1700 failing, so it's quite good coverage. If you find more packages that improve on this, please add them.) acl-dev attr-dev binutils-dev cfitsio-dev expect-dev freeglut3-dev libadns1-dev libalure-dev libasound-dev libaspell-dev libatlas-dev libaugeas-dev libavcodec-dev libavfilter-dev libavformat-dev libavutil-dev libbibutils-dev libbluetooth-dev libbz2-dev libcal3d12-dev libcmph-dev libcrack2-dev libcrypto++-dev libcsound64-dev libctemplate-dev libcurl-dev libcv-dev libcwiid-dev libdb-dev libdevil-dev libdpkg-dev libev-dev libevent-dev libexif-dev libfam-dev libfcgi-dev libfftw3-dev libfltk1.3-dev libfreenect-dev libftgl-dev libfuse-dev libgd2-xpm-dev libgeoip-dev libglfw-dev libglpk-dev libgmime-2.6-dev libgnome-keyring-dev libgnutls-dev libgnutls-dev libgpcl-dev libhighgui-dev libimlib2-dev libinsighttoolkit4-dev libjasper-dev libjudy-dev libkyotocabinet-dev liblapack-dev libldap2-dev libldap2-dev libleveldb-dev libmagic-dev libmarkdown2-dev libmecab-dev libmpfr-dev libmtp-dev libmx-dev libmysqlclient-dev libncurses-dev libncurses-dev libnotmuch-dev libobjc-4.7-dev libodbc1 libode-dev libogg-dev libois-dev libopenal-dev libpam0g-dev libpcap-dev libpoker-eval-dev libportaudio-dev libpulse-dev libqd-dev libqrencode-dev libraw1394-dev libreadline-dev libscsynth1 libselinux-dev libsnappy-dev libsndfile1-dev libsqlite3-dev libssl-dev libssl-dev libst-dev libsvm-dev libtalloc-dev libtbb-dev libtheora-dev libtiff-dev libtokyocabinet-dev libtokyotyrant-dev libtre-dev libuuid-dev libv4l-dev libvxl1-dev libxapian-dev libxen-dev libxerces-c-dev libxine-dev libxmmsclient-dev libxosd-dev libxqilla-dev libxss-dev libxtst-dev libyaml-dev libz-dev libzephyr-dev libzmq-dev linux-libc-dev tcl-dev wx2.8-headers xmms2-dev ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Testing invasive proposals with Hackager
On 13 June 2013 09:59, Niklas Hambüchen m...@nh2.me wrote: In many discussions we make guesses about how much code proposals like Functor = Monad would break. You can use https://github.com/dterei/Hackager to build all of Hackage (preferably in a VM). Of course many packages have external dependencies, so I'd like to share the following list of packages to save you some time. (These are the names of packages suited for a Ubuntu 13.04 VM, and with these installed, 2800 packages are successfully built and 1700 failing, so it's quite good coverage. If you find more packages that improve on this, please add them.) awesome! How do we add packages to the list; do you have a github repo for it? Conrad. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Examples of MVars usage
First of all, thank you for your suggestions. You can try GitHub's code search For the moment I am ignoring Github because it's harder to separate stable development from unstable. Even so, it might be worth the trouble to check out github soon. Thank you, Lucas. Also take a look at Control.Concurrent.Chan in the base library: Yes, the base package seems like a good one for inclusion. Thank you, Bas. []'s -- Francisco 2013/6/12 Bas van Dijk v.dijk@gmail.com On 12 June 2013 21:29, Francisco M. Soares Nt. xfrancisco.soa...@gmail.com wrote: I am looking for packages on hackage which use MVars extensively. Those which create plenty of MVars Hi Francisco, Also take a look at Control.Concurrent.Chan in the base library: http://hackage.haskell.org/packages/archive/base/latest/doc/html/Control-Concurrent-Chan.html A big Chan has a lot of MVars inside. Bas ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Haskell Platform 2013.2.0.0 64bit.pkg
Today I cleared out everything, using uninstall-hs and rm -rf ~/.cabal ~/Library/Haskell I downloaded Haskell Platform 2013.2.0.0 64bit.pkg and installed it. I was unsuccessful in installing the packages I wanted using cabal install, which suggested running ghc-pkg check. So I cleared out everything again and reinstalled the HP. In the admin account, ghc-pkg check says Warning: haddock-interfaces: /Library/Haskell/ghc-7.6.3/lib/haskell-platform-2013.2.0.0/ doc/html/haskell-platform.haddock doesn't exist or isn't a file Warning: haddock-html: /Library/Haskell/ghc-7.6.3/lib/haskell-platform-2013.2.0.0/ doc/html doesn't exist or isn't a directory ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANN: Angel 0.4.2
I'm pleased to announce the release of Angel 0.4.2 and that I have officially taken over maintainership of this project. Thanks to Jamie Turner for starting such a great project and allowing me to take over this project. angel is a daemon that runs and monitors other processes. It is similar to djb's daemontools or the Ruby project god. It's goals are to keep a set of services running, and to facilitate the easy configuration and restart of those services. 0.4.1 added the count option to the config to control the number of instances of a particular process to start. 0.4.2 added the pidfile option to specify the path of a pidfile to generate when monitoring processes. -- Michael Xavier http://www.michaelxavier.net ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell Platform 2013.2.0.0 64bit.pkg
* Richard A. O'Keefe o...@cs.otago.ac.nz [2013-06-13 17:37:57+1200] Today I cleared out everything, using uninstall-hs and rm -rf ~/.cabal ~/Library/Haskell I downloaded Haskell Platform 2013.2.0.0 64bit.pkg and installed it. I was unsuccessful in installing the packages I wanted using cabal install, which suggested running ghc-pkg check. So I cleared out everything again and reinstalled the HP. In the admin account, ghc-pkg check says Warning: haddock-interfaces: /Library/Haskell/ghc-7.6.3/lib/haskell-platform-2013.2.0.0/ doc/html/haskell-platform.haddock doesn't exist or isn't a file Warning: haddock-html: /Library/Haskell/ghc-7.6.3/lib/haskell-platform-2013.2.0.0/ doc/html doesn't exist or isn't a directory This is harmless (but should be fixed). Do you need help with your original problem? If so, please give us more details. Roman ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
