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Call pattern specialization limit messages

haskell-cafe - Sat, 06/11/2016 - 4:32am
When I compile Data.Sequence with -dppr-debug, I get several messages about constructor specialization exceeding the call pattern limit. Things like SpecConstr Function ‘$j_ssfy{v} [lid]’ has four call patterns, but the limit is 3 Use -fspec-constr-count=n to set the bound Specialisations: [([sc_sAZr{v} [lid]], [sc_sAZr{v} [lid], lvl_sdmH{v} [lid]]), ([sc_sAZs{v} [lid]], [sc_sAZs{v} [lid], lvl_sw9X{v} [lid]]), ([sc_sAZt{v} [lid]], [sc_sAZt{v} [lid], lvl_swa0{v} [lid]]), ([sc_sAZu{v} [lid]], [sc_sAZu{v} [lid], lvl_swat{v} [lid]])] How can I figure out what function this sort of thing is actually talking about? I'd love to see what benchmarks say about whether tweaking -fspec-constr-count is a good idea, but I don't know what to benchmark. Thanks, David _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo
Categories: Offsite Discussion

All-fail case in asum

haskell-cafe - Fri, 06/10/2016 - 3:37pm
Hello I want to define some parser such way: myParser = tryA <|> tryB <|> fail "input must be either A or B" It works. But then I want to rewrite it with asum: myParser = asum [tryA, tryB, fail "must be A or B"] It works, but the wrong way. Instead of my error it writes "empty". Just "empty". It is so because in base library asum = foldr (<|>) empty What if it was defined asum [] = empty asum [x:xs] = x <|> asum xs It would help me with my parser. But what can this break? Why isn't this done yet?
Categories: Offsite Discussion

GHC 8 + ImpredictiveTypes + $

haskell-cafe - Fri, 06/10/2016 - 9:59am
Hi, I have had a number of trivial compilation failures in many of my projects that contain instances for MonadBaseControl (from monad-control) since upgrading to GHC 8. Now, I say 'trivial' since the actual fix is incredibly minor - a change of compose (.) to apply ($). What was less trivial was the (additional) hair loss arriving at the fix. I've put together a minimal example that demonstrates both the failing (pre-GHC8) and the fixed (GHC8) instances here: https://gist.github.com/brendanhay/e6f2501c15ac5160ca7dbb6ada6777f0 Since I found the error message somewhat directionless, I'd like some help actually understanding the root cause and why the 'fix' works: * I assume previously GHC did not fully check type aliases that were impredictive prior to GHC 8? * What does this imply for a type alias such as for the alias RunInBase used in monad-control that contains RankNTypes: http://hackage.haskell.org/package/monad-control-1.0.1.0/docs/Control-Monad-Trans-Control.html#t:RunInBase - Is such an alias not
Categories: Offsite Discussion

couldn't match expected type ByteString with actual type IO ByteString

haskell-cafe - Thu, 06/09/2016 - 1:07pm
Hello All, I'm getting the following error: /apps/workspace/hade/src/Step/ReadExcel.hs:39:23: Couldn't match expected type ‘L.ByteString’ with actual type ‘IO L.ByteString’ In the first argument of ‘IBuf’, namely ‘j’ In the second argument of ‘sendChan’, namely ‘(IBuf j)’ when I compile the following code: data Buf = IChan (SendPort Buf) | IBuf (L.ByteString) deriving (Show,Generic,Typeable) instance Binary Buf readExcel :: Process() readExcel = do sendChan chan (IBuf j) where IChan chan = expect j = do r <- toTableRowsFromFile 8 "final-project.xlsx" let b = A.encode r return b remotable ['readExcel] Any ideas as to what I'm doing wrong? Carl _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
Categories: Offsite Discussion

FHPC'16 - reminder, and deadline extension

General haskell list - Thu, 06/09/2016 - 12:54pm
Dear colleagues, Following several requests for an extension, the submission deadline for FHPC'16 has been extended by 5 days to 15th June. ====================================================================== CALL FOR PAPERS FHPC 2016 The 5th ACM SIGPLAN Workshop on Functional High-Performance Computing Nara, Japan September 22, 2016 https://sites.google.com/site/fhpcworkshops/ Co-located with the International Conference on Functional Programming (ICFP 2016) Submission Deadline: Wednesday, 15 June, 2016 (anywhere on earth) ====================================================================== The FHPC workshop aims at bringing together researchers exploring uses of functional (or more generally, declarative or high-level) programming technology in application domains where high performance is essential. The aim of the meeting is to
Categories: Incoming News

FHPC'16 - deadline extension to 14th June

haskell-cafe - Thu, 06/09/2016 - 10:14am
Dear colleagues, Following several requests for an extension, the submission deadline for FHPC'16 has been extended by 5 days to 15th June. ====================================================================== CALL FOR PAPERS FHPC 2016 The 5th ACM SIGPLAN Workshop on Functional High-Performance Computing Nara, Japan September 22, 2016 https://sites.google.com/site/fhpcworkshops/ Co-located with the International Conference on Functional Programming (ICFP 2016) Submission Deadline: Wednesday, 15 June, 2016 (anywhere on earth) ====================================================================== The FHPC workshop aims at bringing together researchers exploring uses of functional (or more generally, declarative or high-level) programming technology in application domains where high performance is essential. The aim of the meeti
Categories: Offsite Discussion

Haskell in Leipzig 2016: Second Call for Papers

haskell-cafe - Thu, 06/09/2016 - 9:29am
                             Haskell in Leipzig                             September 14-15, 2016                             HTKW Leipzig, Germany                          http://hal2016.haskell.org/ Allow me to remind everyone of the opportunity to talk about your research, projects or ideas at this year’s Haskell in Leipzig. The deadline is three weeks from now. == News == Unsure about whether HaL is interesting to you? No need to worry: Alejandro Russo (from Chalmers) is our keynote speaker and will talk about his work on information-flow control (i.e. SecLib, LIO, MAC, HLIO) – a great topic that is of interest to researchers, practitioners and beginners alike.  == About HaL == The workshop series “Haskell in Leipzig”, now in its 11th year, brings together Haskell developers, Haskell researchers, Haskell enthusiasts and Haskell beginners to listen to talks, take par
Categories: Offsite Discussion

Call for talks: Haskell Implementors Workshop 2016, Sep 24 (FIXED), Nara

glasgow-user - Thu, 06/09/2016 - 8:17am
(...and now with the right date in the subject line!) Call for Contributions ACM SIGPLAN Haskell Implementors' Workshop http://haskell.org/haskellwiki/HaskellImplementorsWorkshop/2016 Nara, Japan, 24 September, 2016 Co-located with ICFP 2016 http://www.icfpconference.org/icfp2016/ Important dates --------------- Proposal Deadline: Monday, 8 August, 2016 Notification: Monday, 22 August, 2016 Workshop: Saturday, 24 September, 2016 The 8th Haskell Implementors' Workshop is to be held alongside ICFP 2016 this year in Nara. It is a forum for people involved in the design and development of Haskell implementations, tools, libraries, and supporting infrastructure, to share their work and discuss future directions and collaborations with others. Talks and/or demos are proposed by submitting an abstract, and selected by a small program committee. There will be no published proceedings; the workshop wil
Categories: Offsite Discussion

Call for talks: Haskell Implementors Workshop 2016, Aug 24, Nara

glasgow-user - Thu, 06/09/2016 - 8:14am
Call for Contributions ACM SIGPLAN Haskell Implementors' Workshop http://haskell.org/haskellwiki/HaskellImplementorsWorkshop/2016 Nara, Japan, 24 September, 2016 Co-located with ICFP 2016 http://www.icfpconference.org/icfp2016/ Important dates --------------- Proposal Deadline: Monday, 8 August, 2016 Notification: Monday, 22 August, 2016 Workshop: Saturday, 24 September, 2016 The 8th Haskell Implementors' Workshop is to be held alongside ICFP 2016 this year in Nara. It is a forum for people involved in the design and development of Haskell implementations, tools, libraries, and supporting infrastructure, to share their work and discuss future directions and collaborations with others. Talks and/or demos are proposed by submitting an abstract, and selected by a small program committee. There will be no published proceedings; the workshop will be informal and interactive, with a flexible timetabl
Categories: Offsite Discussion

ANN: Intero for Emacs

haskell-cafe - Wed, 06/08/2016 - 1:01pm
Here is a new Emacs package providing *very basic* Haskell programmer needs: - Type checking - Autocompletion - Go to definition - Type of selection - A basic REPL support It’s very simple, tries to *just work*, is based on Stack (required), the Emacs package auto-installs the correct version of its backend within your Stack working directory, supports the recently released GHC 8 all the way back to GHC 7.8.3. Having to configure anything to get basic functionality is considered a bug. The home page is here with details and demonstrations: http://commercialhaskell.github.io/intero/ The GitHub project where you can submit feature requests or bug reports: https://github.com/commercialhaskell/intero Thanks for reading! ​ _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
Categories: Offsite Discussion

so strange but interesting

haskell-cafe - Wed, 06/08/2016 - 11:07am
Hi, I know it might be something strange, but still so interesting, you have to see it here <http://spalogoxe.njtec.com/aebez> Warmest, dek5< at >yandex.ru _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
Categories: Offsite Discussion

[ANN] New docs for the Aivika simulation platform

haskell-cafe - Wed, 06/08/2016 - 9:37am
Hi Cafe, I wrote a new article "Aivika - A Constructor of General-Purpose Simulation Libraries" [1]. It uncovers key ideas of that how I implemented nested simulation and parallel distributed simulation in the Aivika platform [2]. Monads, immutable data structures, managed side effects, continuations, streams, recursive computations are all those things that are widely used in Aivika. The article can be useful for those who will have a willingness to use my simulation libraries for nested simulation, or distributed simulation, or some other field I cannot still imagine. Finally, I wrote a small tutorial for beginners [3]. It takes a simple discrete event simulation model and shows how we can add a Monte-Carlo experiment, save the results in the CSV files, plot histograms and charts, for the example, the deviation chart with a trend and confidence interval using rule 3-sigma. This tutorial can be used for quick diving into Aivika. All the programming code is written in Haskell. Best regards, David Sorokin
Categories: Offsite Discussion

ANN: SciFlow-0.5.0

haskell-cafe - Tue, 06/07/2016 - 10:48pm
Hi Cafe, I've been working on a package to manage data analysis pipelines, mainly for personal use. But I feel there may be others who are interested in this as well, so I just published an up-to-date version to hackage. Briefly, this package help you design and manage data analysis pipelines written in Haskell, with computation steps being just Haskell functions with type: a -> IO b. I use template Haskell to construct the dependency graph, and computation steps are assembled according to the graph and type checked at compile time. Each step can be configured to run either locally or on a remote machine. Concurrency is also supported. Independent steps will run simultaneously. Take a look at https://github.com/kaizhang/SciFlow for breif introduction and some examples. This package is still under heavy development, but it is quite stable otherwise as I've been using it on our cluster for some time. I hope you would find it useful and any feedback is welcome! _______________________________________________
Categories: Offsite Discussion

How to capture the output of GHCi :show command

haskell-cafe - Tue, 06/07/2016 - 7:02pm
I would like to be able to bind the output of GHCi's :show to a variable, but I don't see a nice way to do so. Is it possible to do this directly in GHCi? My specific use for this is appending to the current prompt.
Categories: Offsite Discussion

Vacancy: Professor Software technology at UtrechtUniversity

haskell-cafe - Tue, 06/07/2016 - 5:08pm
The Faculty of Science at Utrecht University is seeking to appoint a Full Professor in Software Technology to lead, alongside the other two chairs, the division of Software Systems within the Faculty. The full Professor directs and supervises research in the field of software technology, specifically in the design and development of formalisms and methodologies for effective program construction and program analysis. She/he develops new initiatives, aiming at research programs in software technology. This includes the acquisition of external research funds, both at the national and international levels, and the dissemination of research results and its applications to the relevant research communities. The full professor has a leading role in teaching and supervision. She or he contributes to the department’s curriculum development at BSc, MSc and PhD levels. The full professor plays an active role in the leadership and administrative duties of the Department and/or Faculty. For more information about
Categories: Offsite Discussion

Vacancy: Professor Software technology at UtrechtUniversity

General haskell list - Tue, 06/07/2016 - 5:07pm
The Faculty of Science at Utrecht University is seeking to appoint a Full Professor in Software Technology to lead, alongside the other two chairs, the division of Software Systems within the Faculty. The full Professor directs and supervises research in the field of software technology, specifically in the design and development of formalisms and methodologies for effective program construction and program analysis. She/he develops new initiatives, aiming at research programs in software technology. This includes the acquisition of external research funds, both at the national and international levels, and the dissemination of research results and its applications to the relevant research communities. The full professor has a leading role in teaching and supervision. She or he contributes to the department’s curriculum development at BSc, MSc and PhD levels. The full professor plays an active role in the leadership and administrative duties of the Department and/or Faculty. For more information about
Categories: Incoming News

On-site GHC-related Haskell/C opportunity atPositive Technologies (Moscow)

haskell-cafe - Tue, 06/07/2016 - 1:07pm
Good day! The Moscow office of Positive Technologies (https://www.ptsecurity.com) is looking for an experienced Haskell developer with a strong C background. You will be working in a team that develops a next generation security platform: think widely available, easy to use, dramatically enhanced security. In particular, we want you to help rewrite our core application in Haskell, which in turn requires porting GHC runtime to run on bare metal. Details can be seen in our Reddit posting: https://www.reddit.com/r/haskell/comments/4msraq/onsite_ghcrelated_haskellc_opportunity_at/ To apply, send you resume or questions to career< at >ptsecurity.com and CC skosyrev< at >ptsecurity.com.
Categories: Offsite Discussion

uninstalling ghc-8.0.1-x86_64 installed through"install-haskell-platform.sh"

haskell-cafe - Mon, 06/06/2016 - 4:03pm
Hi all, How can I uninstall cleanly ghc-8.0.1-x86_64 that I installed using the script install-haskell-platform.sh (found on haskell.org website under Generic Linux). I'm on ubuntu Trusty. Thanks, Pat _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
Categories: Offsite Discussion

WADT 2016 -- Extended Deadline

General haskell list - Mon, 06/06/2016 - 2:16pm
CFP: WADT 2016 - 23rd International Workshop on Algebraic Development Techniques (extended deadline) Link: http://cs.swan.ac.uk/wadt16/ When Sep 21, 2016 - Sep 24, 2016 Where Gregynog, UK Submission Deadline June 17, 2016 (extended) Notification July 3, 2016 (extended) Final Version Due July 15, 2016 AIMS AND SCOPE The algebraic approach to system specification encompasses many aspects of the formal design of software systems. Originally born as formal method for reasoning about abstract data types, it now covers new specification frameworks and programming paradigms (such as object-oriented, aspect-oriented, agent-oriented, logic and higher-order functional programming) as well as a wide range of application areas (including information systems, concurrent, distributed and mobile systems). The workshop will provide an opportunity to present recent and ongoing work, to meet colleagues, and to discuss new ideas and future trends. TOP
Categories: Incoming News

New Haddock

General haskell list - Mon, 06/06/2016 - 2:03pm
I couldn’t find an announcement of the new version of Haddock. You can now document your libraries even more beautifully. For example, will render as https://hackage.haskell.org/package/random-fu-0.2.7.0/docs/Data-Random-Distribution-Binomial.html#v:integralBinomialPDF <https://hackage.haskell.org/package/random-fu-0.2.7.0/docs/Data-Random-Distribution-Binomial.html#v:integralBinomialPDF> Also don’t forget you can put really nice diagrams in your documentation e.g. http://hackage.haskell.org/package/diagrams-contrib-1.3.0.7/docs/Diagrams-Example-Logo.html <http://hackage.haskell.org/package/diagrams-contrib-1.3.0.7/docs/Diagrams-Example-Logo.html> and http://hackage.haskell.org/package/diagrams-contrib-1.3.0.7/docs/Diagrams-TwoD-Layout-Tree.html <http://hackage.haskell.org/package/diagrams-contrib-1.3.0.7/docs/Diagrams-TwoD-Layout-Tree.html>. Dominic Steinitz dominic< at >steinitz.org http://idontgetoutmuch.wordpress.com _______________________________________________ Haskell mailing list Haskell< at >haskel
Categories: Incoming News