- Haskell-Cafe - Haskell.org

Install on Ubuntu
by Galaxy Being 28 Mar '21

28 Mar '21

I've found a Haskell setup guide here, but after the stack setup it wants to install cabal curl -sSL https://get.haskellstack.org | sh then stack install cabal-install cabal update Why do I want to install cabal after stack? Any advice welcome on the "definitive setup." Just started a new machine with Ubuntu 20.10 on it. LB

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Does Haskell have this SML syntax?
by Galaxy Being 26 Mar '21

26 Mar '21

I saw this in *The Little MLer*, a book on SML datatype 'a list = Empty | Cons of 'a * 'a list fun subst_c (pred) = fn (n,Empty) => Empty | (n,Cons(e,t)) => if pred (e) then Cons (n,subst_c (pred) (n,t)) else Cons (e,subst_c (pred) (n,t)) The data type is just a homemade list, and the function subst_c takes a predicate ('a -> Bool) and determines whether an incoming list's elements pass or fail. What is interesting is the fn ... => ... part which takes in more parameters, namely an 'a and an 'a list. Technically this fn... is an anonymous, nameless function, and it seems bizarre to me that it's nested inside the named function but still taking in parameters as if it were at the top level. Here's a previous version showing all three parameters at the top level fun subst_c (pred) (n,Empty) = Empty ... The purpose of the first function was to demonstrate currying. IOW, what the second unnamed function is doing behind the scenes can be broken down to two-stages (currying) of the first with named, then unnamed functions. So my question is, is there anything like this in Haskell where a function inside a function -- named or anonymous -- can take incoming parameters as if it were top level? LB

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Query regarding GSOC
by Shubham Mittal 25 Mar '21

25 Mar '21

Hello I am Shubham from India currently pursuing BTech IT 2nd year. I would like to contribute to Haskell-Cafe as a part of GSOC. Can you please guide me how I can i do so? Thanks and Regards, Shubham Mittal

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IFL2021 First call for papers
by Pieter Koopman 24 Mar '21

24 Mar '21

================================================================================ IFL 2021 33rd Symposium on Implementation and Application of Functional Languages venue: online 1 - 3 September 2021 https://ifl21.cs.ru.nl <https://ifl21-publicity-dot-yamm-track.appspot.com/Redirect?ukey=1NdKhGOLpm…> ================================================================================ Scope The goal of the IFL symposia is to bring together researchers actively engaged in the implementation and application of functional and function-based programming languages. IFL 2021 will be a venue for researchers to present and discuss new ideas and concepts, work in progress, and publication-ripe results related to the implementation and application of functional languages and function-based programming. Industrial track and topics of interest This year's edition of IFL explicitly solicits original work concerning *applications* of functional programming in industry and academia. These contributions will be reviewed by experts with an industrial background. Topics of interest to IFL include, but are not limited to: * language concepts * type systems, type checking, type inferencing * compilation techniques * staged compilation * run-time function specialisation * run-time code generation * partial evaluation * (abstract) interpretation * meta-programming * generic programming * automatic program generation * array processing * concurrent/parallel programming * concurrent/parallel program execution * embedded systems * web applications * (embedded) domain-specific languages * security * novel memory management techniques * run-time profiling performance measurements * debugging and tracing * testing and proofing * virtual/abstract machine architectures * validation, verification of functional programs * tools and programming techniques * applications of functional programming in the industry, including ** functional programming techniques for large applications ** successes of the application functional programming ** challenges for functional programming encountered ** any topic related to the application of functional programming that is interesting for the IFL community Post-symposium peer-review Following IFL tradition, IFL 2021 will use a post-symposium review process to produce the formal proceedings. Before the symposium authors submit draft papers. These draft papers will be screened by the program chairs to make sure that they are within the scope of IFL. The draft papers will be made available to all participants at the symposium. Each draft paper is presented by one of the authors at the symposium. After the symposium every presenter is invited to submit a full paper, incorporating feedback from discussions at the symposium. Work submitted to IFL may not be simultaneously submitted to other venues; submissions must adhere to ACM SIGPLAN's republication policy. The program committee will evaluate these submissions according to their correctness, novelty, originality, relevance, significance, and clarity, and will thereby determine whether the paper is accepted or rejected for the formal proceedings. We plan to publish these proceedings in the International Conference Proceedings Series of the ACM Digital Library, as in previous years. Moreover, the proceedings will also be made publicly available as open access. Important dates Submission deadline of draft papers: 17 August 2021 Notification of acceptance for presentation: 19 August 2021 Registration deadline: 30 August 2021 IFL Symposium: 1-3 September 2021 Submission of papers for proceedings: 6 December 2021 Notification of acceptance: 3 February 2022 Camera-ready version: 15 March 2022 ### Submission details All contributions must be written in English. Papers must use the ACM two columns conference format, which can be found at: http://www.acm.org/publications/proceedings-template <https://ifl21-publicity-dot-yamm-track.appspot.com/Redirect?ukey=1NdKhGOLpm…> Peter Landin Prize The Peter Landin Prize is awarded to the best paper presented at the symposium every year. The honoured article is selected by the program committee based on the submissions received for the formal review process. The prize carries a cash award equivalent to 150 Euros. Organisation IFL 2021 Chairs: Pieter Koopman and Peter Achten, Radboud University, The Netherlands IFL Publicity chair: Pieter Koopman, Radboud University, The Netherlands PC (under construction): Peter Achten (co-chair) - Radboud University, Netherlands Thomas van Binsbergen - University of Amsterdam, Netherlands Edwin Brady - University of St. Andrews, Scotland Laura Castro - University of A Coruña, Spain Youyou Cong - Tokyo Institute of Technology, Japan Olaf Chitil - University of Kent, England Andy Gill - University of Kansas, USA Clemens Grelck - University of Amsterdam, Netherlands John Hughes - Chalmers University, Sweden Pieter Koopman (co-chair) - Radboud University, Netherlands Cynthia Kop - Radboud University, Netherlands Jay McCarthey - University of Massachussetts Lowell, USA Neil Mitchell - Facebook, England Jan De Muijnck-Hughes - Glasgow University, Scotland Keiko Nakata - SAP Innovation Center Potsdam, Germany Jurriën Stutterheim - Standard Chartered, Singapore Simon Thompson - University of Kent, England Melinda Tóth - Eötvos Loránd University, Hungary Phil Trinder - Glasgow University, Scotland Meng Wang - University of Bristol, England Viktória Zsók - Eötvos Loránd University, Hungary Virtual symposium Because of the Covid-19 pandemic, this year IFL 2021 will be an online event, consisting of paper presentations, discussions and virtual social gatherings. Registered participants can take part from anywhere in the world. Acknowledgments This call-for-papers is an adaptation and evolution of content from previous instances of IFL. We are grateful to prior organisers for their work, which is reused here. [image: beacon]

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ANN closed-intervals-0.1
by Olaf Klinke 24 Mar '21

24 Mar '21

Dear Cafe, I am pleased to announce the first release of closed-intervals [1], a package for querying and manipulating collections of closed intervals in totally ordered types. Other packages exist which either deal with a single interval type [2,4] or provide an interval type class [3]. Having both closed, open and half-open intervals makes the interface complicated, however. The focus of closed-intervals is on intervals including both end-points and is intended to be used on records with length or duration information. My use cases are mostly sequences of annotated time intervals [*], parsed from time-stamped data. Against these sequences overlap-, coverage- and intersection queries are run using single intervals as query. The package contains many doctests. Testing builds on Henning Thielemann's doctest-extract [5] and doctest-exitcode-io [6] packages. closed-intervals is, after provenience [7], the second package in an effort to open-source my employer's entire Haskell codebase. We will gradually publish from general to problem-specific. Cheers, Olaf [1] https://hackage.haskell.org/package/closed-intervals [2] https://hackage.haskell.org/package/data-interval [3] https://hackage.haskell.org/package/IntervalMap [4] https://hackage.haskell.org/package/intervals [5] https://hackage.haskell.org/package/doctest-extract [6] https://hackage.haskell.org/package/doctest-exitcode-io [7] https://hackage.haskell.org/package/provenience [*] Since time types are fine-grained and a time point is an idealized concept, the question of end-point inclusion is not that relevant for time intervals. We do distinguish between intersection in end-points and proper intersection, though.

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Implementing Dragon, Uber's data-integration tool for property graphs
by Jeffrey Brown 23 Mar '21

23 Mar '21

If your interests include any nonempty subset of Haskell, category theory and graphs, you might enjoy this. Online attendance is free. (For all I know in-person attendance is free too, if you live near SF area.) https://www.meetup.com/Category-Theory/events/nnrhgsyccfbhc -- Jeff Brown | Jeffrey Benjamin Brown LinkedIn <https://www.linkedin.com/in/jeffreybenjaminbrown> | Github <https://github.com/jeffreybenjaminbrown> | Twitter <https://twitter.com/carelogic> | Facebook <https://www.facebook.com/mejeff.younotjeff> | very old Website <https://msu.edu/~brown202/>

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Global Package Install
by A. Mc. 22 Mar '21

22 Mar '21

Hello, I am trying to add the package System.Random to be able to run it the same way Data.List or Data.Char, et cetera does in ghci and in doing a ghc command line build. I've tried using $ stack ghci --package random which I have to run every single time I want to load a module that imports anything from System.Random and I've already tried $ cabal install --lib random which only works with cabal, and I've used the command $ stack install random, which says 'cache populated' but if a restart and load a dependent module, still is not working for me. I've also tried to update the .yaml file by putting System.Random into the brackets is the sr directory, but this I'm guessing isn't what you're supposed to do as it doesn't work either. I'm using Cygwin on a Windows 10 operating system. Your assistance in this matter would be greatly appreciated. Thank you for your time.

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Call for Talks: Haskell Implementors' Workshop
by Ningning Xie 22 Mar '21

22 Mar '21

Call for Talks ACM SIGPLAN Haskell Implementors' Workshop https://icfp21.sigplan.org/home/hiw-2021 Virtual, 22 Aug, 2021 Co-located with ICFP 2021 https://icfp21.sigplan.org/ Important dates --------------- Deadline: Wednesday, 30 June, 2021 (AoE) Notification: Wednesday, 14 July, 2021 Workshop: Sunday, 22 August, 2021 The 13th Haskell Implementors' Workshop is to be held alongside ICFP 2021 this year virtually. 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 open spaces in the timetable and room for ad-hoc discussion, demos, and lightning short talks. Scope and target audience ------------------------- It is important to distinguish the Haskell Implementors' Workshop from the Haskell Symposium which is also co-located with ICFP 2021. The Haskell Symposium is for the publication of Haskell-related research. In contrast, the Haskell Implementors' Workshop will have no proceedings -- although we will aim to make talk videos, slides and presented data available with the consent of the speakers. The Implementors' Workshop is an ideal place to describe a Haskell extension, describe works-in-progress, demo a new Haskell-related tool, or even propose future lines of Haskell development. Members of the wider Haskell community encouraged to attend the workshop -- we need your feedback to keep the Haskell ecosystem thriving. Students working with Haskell are specially encouraged to share their work. The scope covers any of the following topics. There may be some topics that people feel we've missed, so by all means submit a proposal even if it doesn't fit exactly into one of these buckets: * Compilation techniques * Language features and extensions * Type system implementation * Concurrency and parallelism: language design and implementation * Performance, optimisation and benchmarking * Virtual machines and run-time systems * Libraries and tools for development or deployment Talks ----- We invite proposals from potential speakers for talks and demonstrations. We are aiming for 20-minute talks with 5 minutes for questions and changeovers. We want to hear from people writing compilers, tools, or libraries, people with cool ideas for directions in which we should take the platform, proposals for new features to be implemented, and half-baked crazy ideas. Please submit a talk title and abstract of no more than 300 words. Submissions should be made via HotCRP. The website is: https://icfp-hiw21.hotcrp.com/ We will also have lightning talks session. These have been very well received in recent years, and we aim to increase the time available to them. Lightning talks be ~7mins and are scheduled on the day of the workshop. Suggested topics for lightning talks are to present a single idea, a work-in-progress project, a problem to intrigue and perplex Haskell implementors, or simply to ask for feedback and collaborators. Logistics --------- Due to the on-going COVID-19 situation, ICFP (and, consequently, HIW) will be held remotely this year. However, the organizers are still working hard to provide for a great workshop experience. While we are sad that this year will lack the robust hallway track that is often the highlight of HIW, we believe that this remote workshop presents a unique opportunity to include more of the Haskell community in our discussion and explore new modes of communicating with our colleagues. We hope that you will join us in making this HIW as vibrant as any other. Program Committee ----------------- * Dominique Devriese (Vrije Universiteit Brussel) * Daan Leijen (Microsoft Research) * Andres Löh (Well-Typed LLP) * Julie Moronuki (Typeclass Consulting) * John Wiegley (DFINITY) * Ningning Xie (the University of Hong Kong) * Edward Z. Yang (Facebook AI Research) Contact ------- * Ningning Xie <xnning at hku.hk>

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International Conference on Recent Theories and Applications in Transportation and Mobility - (RTATM 2021) Prague
by matteo＠confscience.com 22 Mar '21

22 Mar '21

Call for papers ************************************************* International Conference on Recent Theories and Applications in Transportation and Mobility - (RTATM 2021) Prague - Czech Republic, October 14-15, 2021 https://confscience.com/rtatm/ Submission deadline: April 1, 2021 All papers accepted in RTATM 2021 will be published in Springer CCIS (Communications in Computer and Information Science). CCIS is abstracted/indexed in Scopus, SCImago, EI-Compendex, Mathematical Reviews, DBLP, Google Scholar, and Thomson Reuters Conference Proceedings Citation (Former ISI Proceedings) *************************************************************************** IMPORTANT DATES: - Paper Submission: April 1, 2021 - Acceptance Notification: July 1, 2021 - Final Manuscript Due: September 1, 2021 *************************************************************************** The RTATM 2021 conference will be held in Conjunction with: International Conference on Applied Data Science and Intelligence (ADSI 2021) International Conference on Informatics Revolution for Smarter Healthcare (IRSH 2021) *************************************************************************** TOPICS: Authors are invited to submit their original papers to address the topics of the conference, including but not limited to: FUNDAMENTALS AND THEORIES - Modelling and Simulation Algorithms - Vehicular Wireless Medium Access Control - V2X communications - Routings and Protocols for Connected Vehicles - Mobility Models and Architectures - Distribution Strategies - Traffic Incident Management Systems - Bio-Inspired Approaches - Optimization and Collaboration - Automatic Control in Vehicular Networks - Energy-aware Connected Mobility - Programming Languages - Sustainable Transportation - Multimodal Transportation Networks and Systems - Systemsb Integration - Driver Behavior Models and Simulation - Human Factors and Travel Behaviour - Green Mobility - Regulations and Bylaws for Intelligent - Transportation and Mobility SMART TRANSPORTATION AND LOGISTICS - Mobility Management - Connected Vehicles - VANETs - Predictive Logistics - Spatio-Temporal Event Tracking - Decision Support Systems - Emergency Management - Logistics and E-Commerce - Supply Chain Design and Execution - Supply Chain Management - Advanced Planning Systems - Fleet Management - Multi-Agent Systems - Machine Learning for Smart Logistics - Intelligent Infrastructures - Real-time Analysis of Comprehensive Supply Chain Data - Smart Synchronization of Logistics Processes - New Approaches for Cost Transparency - Big Data for Smart Logistics - Logistics 4.0 - Mobile Networks - Next-Generation Smart Logistics - Performance Management Approaches - Tests and Deployment - Software Defined Networks - Smart Freight Management - Smart Shipment Management - Smart Warehousing - Smart Inventory management DATA AND SERVICES - Real-Time transportation Data Acquisition - Event Detection and Monitoring - Data Warehouses for connected mobility - Data mining and Data analytics - Data Worthiness in Connected Vehicles - Data Trustworthiness for effective transportation and mobility - Road Traffic Data Analytics - Structured and Unstructured Data for Connected Mobility - Volunteered Geographic Information (VGI) - Data Representation for Connected Mobility - Transportation Data Mining - Transportation and mobility Data Visualization - Cognitive and Context-aware Intelligence - Transportation Decision Support Systems - Mobility as a Service (MaaS) - Intelligent Transportation Services - Smart Mobility Services - Big Data and Vehicle Analytics - Massive Data Management - Collective and connected Intelligence - Next Generation Services - Driver Behaviour Analysis - Geo-Spatial Services - Service-Oriented Architecture (SOA) - Web and Mobile Services SAFETY, SECURITY, AND HAZARD MANAGEMENT - Security Issues in Vehicular Communications - Safety Applications of Connected Vehicles - Weather-related Safety solutions - V2V, V2I and I2V Road Safety Applications - Connected Mobility for Hazard Management - Risk Management - Road Traffic Crashes Analytics - Traffic Jam Prediction - Resource Allocation for Hazard Management - Trust and Privacy Issues in Logistics - Management of Exceptional Events - New approaches to Networking Security for Transportation Applications - Failure modes, human factors, software safety - Automated Failure Analysis - Performance and Human Error Analysis - Design and Reliability of Control Systems - Dispersion Modelling Software - Quantification of Risk *************************************************************************** OUTSTANDING PAPERS: Based on the peer review scores as well as the presentations at the conference, the authors of outstanding papers will be invited to extend their works for a potential publication in journals special issues with high impact factors. *************************************************************************** PAPER SUBMISSION: Papers must be submitted electronically as PDF files via easychair (https://easychair.org/conferences/?conf=rtatm2021) All papers will be peer reviewed. Length of Full papers: 12-15 pages long (written in the LNCS/CCIS one-column page format, 400 words per page) Length of Short papers: less than 12 pages For more information, please refer to the conference website: https://confscience.com/rtatm/ *************************************************************************** CONTACT For more information, please send an email to info-rtatm(a)confscience.com

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ANN unicode-general-category-0.1.0.0
by Javran Cheng 22 Mar '21

22 Mar '21

Hi Cafe, I'm happy to announce the release of a new package: unicode-general-category. This package provides the same set of functions related to Unicode general category found in Data.Char, but uses information from Unicode 13.0.0 - in addition a set of tools are offered to turn any modern UnicodeData.txt into such a set of functions. I wrote this as a by-product of my recent adventure into parsing Java (it follows Unicode 13, but Data.Char is dependent on GHC versions), but hope this can also be helpful to others in some way. https://hackage.haskell.org/package/unicode-general-category https://github.com/Javran/unicode-general-category Cheers, Javran (Fang) Cheng

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