News aggregator

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 ( 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: To apply, send you resume or questions to career< at > and CC skosyrev< at >
Categories: Offsite Discussion

uninstalling ghc-8.0.1-x86_64 installed through""

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 (found on website under Generic Linux). I'm on ubuntu Trusty. Thanks, Pat _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >
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: 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 <> Also don’t forget you can put really nice diagrams in your documentation e.g. <> and <>. Dominic Steinitz dominic< at > _______________________________________________ Haskell mailing list Haskell< at >haskel
Categories: Incoming News

Having issue in running Haskell code in Atom

haskell-cafe - Sun, 06/05/2016 - 9:21pm
Hello All, I have started learning Haskell couple of days ago. I was looking for an IDE and found Atom as one of them. When I started using it I installed multiple packages and tried running creating Haskell files and saving it. This IDE always gives me following error. Please help to debug this: [Enter steps to reproduce below:] 1. ... 2. ... **Atom Version**: 1.7.4 **System**: Microsoft Windows 10 Pro **Thrown From**: [haskell-ghc-mod]( package, v1.14.5 ### Stack Trace Haskell-ghc-mod: ghc-mod failed to launch. It is probably missing or misconfigured. ENOENT ``` At Error: spawn ghc-mod ENOENT PATH: undefined path: undefined Path: C:\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program F
Categories: Offsite Discussion

haskell-ide-engine versus hsdev (and Debuggers)

haskell-cafe - Sun, 06/05/2016 - 6:35pm
Hello, I am new to Haskell and thinking of contributing to the IDE efforts. I've noticed two projects which aim to provide a "service" that editors and IDEs can call to help present useful information to programmers. I am wondering how these projects differ and why they are separate efforts since they seem to have very similar end goals? Another thing that I am wondering is if either of these two projects aims to provide debugger support and what the general state of debuggers for Haskell is? I've seen a project for a Haskell remote debugger which looks it was ghci/interpreter based and was being used by Eclipse and IntelliJ. It didn't work when I tried it, however, and I am not sure that the project is still active. It also looks like ghc only recently began adding support for debugging compiled Haskell and that initial efforts may be to get things working with gdb or lldb. Am I correctly understanding the current landscape as far as Haskell debuggers go? Thanks! Leonard _________________________________
Categories: Offsite Discussion

Final CFP: 4th ACM SIGPLAN International Workshop onFunctional Art, Music, Modelling and Design

haskell-cafe - Sun, 06/05/2016 - 2:09pm
4th ACM SIGPLAN International Workshop on Functional Art, Music, Modelling and Design Co-located with ICFP Nara, Japan, 24 September, 2016 Key Dates: Submission deadline - June 24 Author Notification - 15 July Camera Ready - 31 July Workshop - September 24, 2016 We welcome submissions from academic, professional, and independent programmers and artists. Final Call for Papers, Demos, *and* Performances The ACM SIGPLAN International Workshop on Functional Art, Music, Modelling and Design (FARM) gathers together people who are harnessing functional techniques in the pursuit of creativity and expression. Functional Programming has emerged as a mainstream software development paradigm, and its artistic and creative use is booming. A growing number of software toolkits, frameworks and environments for art, music and design now employ functional programming languages and techniques. FARM is a forum for exploration and critical evaluation of these developments,
Categories: Offsite Discussion

Strange type error with -XTypeApplications

haskell-cafe - Sat, 06/04/2016 - 9:32pm
This program: * {-# LANGUAGE TypeApplications #-}* * main = print (fromDynamic < at >Int undefined)* produces this error message: * foo.hs:3:15: error:* * • Cannot apply expression of type ‘t0’* * to a visible type argument ‘Int’* * • In the first argument of ‘print’, namely* * ‘(fromDynamic < at >Int undefined)’* * In the expression: print (fromDynamic < at >Int undefined)* * In an equation for ‘main’:* * main = print (fromDynamic < at >Int undefined)* However, I'd expect it to be "Not in scope: fromDynamic" _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >
Categories: Offsite Discussion

Accumulating and threading output of functions

haskell-cafe - Sat, 06/04/2016 - 4:18pm
Hello all, I have a number of functions, whose type is something like this: f:: a -> b -> (b, c) i.e. it returns a modified b and an additional c. Now I want to write a combinator, which assembles a list of such functions into a single one. This combinator will have to thread the bs from one function to the next and accumulate the cs into a single c. While I was able to write this using a fold, I am not happy with it (my first attempt had a bad error in it, which is always a bad sign). Are you aware of any idioms, how to do such things on the beaten track?
Categories: Offsite Discussion

announce: arithmoi

haskell-cafe - Sat, 06/04/2016 - 3:59pm
It is with great pleasure that the arithmoi maintainers (andrew lelechenko and myself) would like to share the release with the haskell community. This release includes a multiplicatively infinite (but addititively finite) increase in test coverage and correspondingly every known bug in arithmoi has been fixed (so theres no known crashing/faulting bugs, and all tested code gives mathematically correct answers) I would especially like to thank Andrew Lelechenko for becoming a fellow maintainer, his incredibly meticulous, clean, thorough engineering is really what made this release possible and excellent. this should treated as a stable library version release. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >
Categories: Offsite Discussion

New version of itself

haskell-cafe - Sat, 06/04/2016 - 2:24pm
Hello all, I find myself frequentlly writing types like this data Logger a l = Lgr { runLogger :: a -> Log l -> (Log l, Logger a l) } The purpose is to give a logger a chance to carry an internal state. It could e.g. choose to log only every n invocations. To do this it must keep track of how many times it has been called. I want to leave such things private to the Logger. (1) I know that this is not an unusal thing to do, but it has an OO feel to it. Is there a more functional alternative to it. Should I just not worry? (2) I can write a combinator which creates a Logger from a list of Loggers. Since each Logger potentially returns a new version of itself, I must always re-assemble the combined logger from all the returned new versions. I am worried that this is a costly operation, particularly when most Loggers just return themselves unaltered. I don't have any hard numbers about the performance penalty though. These Loggers are used in a discrete-event-simulation and they will get called many t
Categories: Offsite Discussion

Month in Haskell Mode May 2016

haskell-cafe - Sat, 06/04/2016 - 12:56pm
Hi, Month in Haskell Mode May 2016 progress report is available:
Categories: Offsite Discussion

Feedback on -Wredundant-constraints

glasgow-user - Fri, 06/03/2016 - 10:33pm
With 8.0.1 freshly arrived, I'm taking on the task of updating a number of our larger projects here at Galois. I made a couple of these comments briefly on a relevant Trac ticket[1], but I wanted to open this discussion to a wider audience. We tend to use -Wall (and -Werror, in CI environments), and so I've had to make decisions about how to handle the new -Wredundant-constraints warnings. So far, I've come to think of it as two different warnings that happen to be combined: Warning 1: a warning for constraints made redundant by superclass relationships, and Warning 2: a warning for unused constraints Overall I'm a fan of Warning 1. It seems very much in the spirit of other warnings such as unused imports. The only stumbling block is how it affects the 3-release compatibility plan with respect to, e.g., the AMP. Most of our code targets a 2-release window, though, so in every such case it has been fine for us to simply remove the offending constraint. Warning 2 on the other hand is far more dubious to me
Categories: Offsite Discussion

10 open roles in expanding team at Standard Chartered

haskell-cafe - Fri, 06/03/2016 - 1:14pm
I have another ten open roles in the growing Strats team at Standard Chartered. These are full time or contract Haskell developer positions in London or Singapore. Details in the post . _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe< at >
Categories: Offsite Discussion

PPPJ 2016, Submission Deadline Extended to June 13 AoE

General haskell list - Fri, 06/03/2016 - 9:49am
******** Due to several requests, the paper submission deadline has been extended to ******** June 13, 2016 AoE (Anywhere on Earth). ******** ******** Registering paper title and abstract before the submission deadline is ******** optional but encouraged. =============================================== PPPJ '16 13th International Conference on Principles and Practices of Programming on the Java Platform: Virtual Machines, Languages, and Tools August 29 - September 2, 2016 Lugano, Switzerland In-cooperation with ACM SIGPLAN, SIGSOFT, SIGAPP and SPEC RG PPPJ '16 is a forum for researchers and practitioners to present and discuss novel results on all aspects of managed languages and their runtime systems, including virtual machines, tools, methods, frameworks, libraries, case studies, and experience reports. Managed languages and runtime systems of interest include, but are not limited to, Java, Scala, JavaScript, Python, Ruby, C#, F#, Clojure, Groovy
Categories: Incoming News

International summer school on metaprogramming(Cambridge, 8-12 Aug 2016)

haskell-cafe - Thu, 06/02/2016 - 10:27pm
==================================================================== International summer school on metaprogramming Robinson College, Cambridge, United Kingdom 8th-12th August, 2016 ==================================================================== Metaprogramming is an approach to improving programs by treating program fragments (such as expressions or types) as values that the program can manipulate. Metaprogramming comes in various forms, including * staged programming: treating expressions as program values. The execution of a staged program is spread over several phases, with each stage using the available data to generate specialized code. Staged programming has a wide variety of applications — numeric computations, parsing, database queries, generic programming, domain specific languages, and many more. Precompiling the staged code can have dramatic performance improvements, in some cases an order of magnitude or more. * generic
Categories: Offsite Discussion

how to reify an API?

haskell-cafe - Thu, 06/02/2016 - 10:00pm
Dear Cafe, I wanted to benchmark (part of) an API of a package, by enumerating all possible (nested) calls by size of their AST, much as smallcheck does it for data. So I made this straightforward AST representation and (generically) got its Serial instances. That last part has been in smallcheck for a long time, and works nicely. But I do wonder if there is a way to get the AST (and corresponding interpreter) with less boilerplate code (than this: ) If you read the code: it also has a type for "AST contexts" because I wanted to iterate them (to produce larger trees). Again - easy to write down, but boring. - J.
Categories: Offsite Discussion

Summer School on Bidirectional Transformations, Oxford,25-29th July 2016

General haskell list - Thu, 06/02/2016 - 4:52pm
Apologies if you have seen this before, but the early registration deadline (June 10th) is fast approaching for SSBX in Oxford. Please pass this on to anyone who may be interested (and consider coming yourself!). * SUMMER SCHOOL ON BIDIRECTIONAL TRANSFORMATIONS Lady Margaret Hall, Oxford, UK 25th to 29th July 2016 TOPIC Bidirectional transformations (BX) are means of maintaining consistency between multiple information sources: when one source is edited, the others may need updating to restore consistency. BX have applications in databases, user interface design, model-driven development, and many other domains. This summer school is one of the closing activities on the "Theory of Least Change for BX" project at Oxford and Edinburgh ( It brings together leading researchers in BX, spanning theory and practice, for a week of lectures in beautiful Oxford. It will be aimed at doctoral students in computer science, but wi
Categories: Incoming News

LOPSTR 2016: 2nd Call for Papers

General haskell list - Wed, 06/01/2016 - 7:21pm
[ Please distribute, apologies for multiple postings. ] ====================================================================== LOPSTR 2016: 2nd Call for Papers ====================================================================== 26th International Symposium on Logic-Based Program Synthesis and Transformation LOPSTR 2016 Edinburgh, UK, September 6-8, 2016 (co-located with PPDP 2016 and SAS 2016) ====================================================================== DEADLINES: Abstract submission: June 7, 2016 Paper/Extended abstract submission: June 14, 2016 ====================================================================== INVITED SPEAKERS: Francesco Logozzo (Facebook, USA) [jointly with PPDP] Greg Morrisett (Cornell University, USA) [jointly with PPDP] Martin Vechev (ETH Zurich, Switzerland) [jointly with SAS ] =====
Categories: Incoming News

ANN: Haskell for Mac trials & educational discount

General haskell list - Wed, 06/01/2016 - 1:51am
Haskell for Mac, the Haskell IDE with interactive playgrounds, now offers a free 14 day trial and educational discounts: Manuel
Categories: Incoming News