- Haskell-Cafe - Haskell.org

Append after index and update items after inserted item with lens
by Cody Goodman 13 Mar '18

13 Mar '18

Hello, I'm trying to insert a new elemnt into a list after a given index and increment the orderId accordingly with the lens library. I'm a bit confused at why this code isn't working: ``` import Control.Lens data A = A { _customOrderId :: Int } deriving Show things = [ A {_customOrderId = 0} , A {_customOrderId = 1} , A {_customOrderId = 2} , A {_customOrderId = 3} ] main = print $ things & ( (_drop 2 %~ ((A 22)<|)) . ((traversed . indices (> 2) . customerOrderIdLens) %~ (+ 1)) ) ``` The first portion works to insert where desired, but the second portion `((traversed . indices (> 2) . customerOrderIdLens) %~ (+ 1))` only increments the order id in indices 4. Any idea why this is happening? Thanks, Cody Goodman

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Call for Contributions: Type-Driven Development 2018
by Niki Vazou 13 Mar '18

13 Mar '18

Hello, The first call for contributions for TyDe is out. Forward it to anyone who might be interested. Best, Niki Vazou ============================================== CALL FOR CONTRIBUTIONS Type 2018: Type-Driven Development https://icfp18.sigplan.org/track/tyde-2018 23-29 Sep, 2018, St. Louis, Missouri (co-located with ICFP) ============================================== *Call for Contributions* We welcome all contributions, both theoretical and practical, on a range of topics including: dependently typed programming; generic programming; design and implementation of programming languages, exploiting types in novel ways; exploiting typed data, data dependent data, or type providers; static and dynamic analyses of typed programs; tools, IDEs, or testing tools exploiting type information; pearls, being elegant, instructive examples of types used in the derivation, calculation, or construction of programs. *Important Dates* Regular paper deadline: Wednesday, June 6, 2018 Extended abstract deadline: Wednesday, June 13, 2018 Author notification: Friday, June 29, 2018 Deadline for camera ready version: August 5, 2018 Workshop: Thursday, September 27, 2018 *Program Committee* - Guillaume Allais, Radboud University Nijmegen, Netherlands - Zena M. Ariola, University of Oregon, USA - David Darais, University of Vermont, USA - Richard Eisenberg, Bryn Mawr College, USA (co-chair) - Jennifer Hackett, University of Nottingham, UK - Shin-ya Katsumata, National Institute of Informatics, Japan - Daan Leijen, Microsoft Research, USA - Shin-Cheng Mu, Academia Sinica, Taiwan - Dominic Orchard, University of Kent, UK - Peter-Michael Osera, Grinnell College, USA - Zoe Paraskevopoulou, Princeton University, USA - Alberto Pardo, Universidad de la Republica, Uruguay - Matthieu Sozeau, University of Paris Diderot, Paris 7, France - Niki Vazou, University of Maryland, USA (co-chair) *Submission details* Submissions should fall into one of two categories: - Regular research papers (12 pages) - Extended abstracts (2 pages) The bibliography will not be counted against the page limits for either category. Regular research papers are expected to present novel and interesting research results, and will be included in the formal proceedings. Extended abstracts should report work in progress that the authors would like to present at the workshop. Extended abstracts will be distributed to workshop attendees but will not be published in the formal proceedings. We welcome submissions from PC members (with the exception of the two co-chairs), but these submissions will be held to a higher standard. Submission is handled through HotCRP: https://tyde18.hotcrp.com/ All submissions should be in portable document format (PDF) and formatted using the ACM SIGPLAN style guidelines: http://www.sigplan.org/Resources/Author/ Note that the ACM SIGPLAN style guidelines have changed from previous years! In particular, submissions should use the new ‘acmart’ format and the two-column ‘sigplan’ subformat (not to be confused with the one-column ‘acmlarge’ subformat!). Extended abstracts must be submitted with the label ‘Extended abstract’ clearly in the title.

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1st CfP: IFL 2018 (30th Symposium on Implementation and Application of Functional Languages)
by Jurriaan Hage 13 Mar '18

13 Mar '18

Hello, Please, find below the first call for papers for IFL 2018. Please forward these to anyone you think may be interested. Apologies for any duplicates you may receive. best regards, Jurriaan Hage Publicity Chair of IFL --- ================================================================================ IFL 2018 30th Symposium on Implementation and Application of Functional Languages University of Massachusetts Lowell, MA, USA September 5th-7th, 2018 http://iflconference.org ================================================================================ ### 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 2018 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. 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 specialization - run-time code generation - partial evaluation - (abstract) interpretation - metaprogramming - 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 - virtual/abstract machine architectures - validation, verification of functional programs - tools and programming techniques - (industrial) applications ### Submissions and peer-review Differently from previous editions of IFL, IFL 2018 solicits two kinds of submissions: * Regular papers (12 pages including references) * Draft papers for presentations ('weak' limit between 8 and 15 pages) Regular papers will undergo a rigorous review by the program committee, and will be evaluated according to their correctness, novelty, originality, relevance, significance, and clarity. A set of regular papers will be conditionally accepted for publication. Authors of conditionally accepted papers will be provided with committee reviews along with a set of mandatory revisions. Regular papers not accepted for publication will be considered as draft papers, at the request of the author. Draft papers will be screened to make sure that they are within the scope of IFL, and will be accepted for presentation or rejected accordingly. Prior to the symposium: Authors of conditionally accepted papers and accepted presentations will submit a pre-proceedings version of their work that will appear in the draft proceedings distributed at the symposium. The draft proceedings does not constitute a formal publication. We require that at least one of the authors present the work at IFL 2018. After the symposium: Authors of conditionally accepted papers will submit a revised versions of their paper for the formal post-proceedings. The program committee will assess whether the mandatory revisions have been adequately addressed by the authors and thereby determines the final accept/reject status of the paper. Our interest is to ultimately accept all conditionally accepted papers. If you are an author of a conditionally accepted paper, please make sure that you address all the concerns of the reviewers. Authors of accepted presentations will be given the opportunity to incorporate the feedback from discussions at the symposium and will be invited to submit a revised full article for the formal post-proceedings. 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. ### Publication The formal proceedings will appear in the International Conference Proceedings Series of the ACM Digital Library. At no time may work submitted to IFL be simultaneously submitted to other venues; submissions must adhere to ACM SIGPLAN's republication policy: http://www.sigplan.org/Resources/Policies/Republication ### Important dates Submission of regular papers: May 25, 2018 Submission of draft papers: July 17, 2018 Regular and draft papers notification: July 20, 2018 Deadline for early registration: August 8, 2018 Submission of pre-proceedings version: August 29, 2018 IFL Symposium: September 5-7, 2018 Submission of papers for post-proceedings: November 7, 2018 Notification of acceptance: December 22, 2018 Camera-ready version: February 10, 2019 ### 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 Authors submit through EasyChair: https://easychair.org/conferences/?conf=ifl2018 ### Peter Landin Prize The Peter Landin Prize is awarded to the best paper presented at the symposium every year. The honored 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. ### Organization and Program committee Chairs: Jay McCarthy & Matteo Cimini, University of Massachusetts Lowell, USA Program Committee: * Arthur Chargu√©raud, Inria, FR * Ben Delaware, Purdue University, USA * Christos Dimoulas, Northwestern University, USA * David Darais, University of Vermont, USA * Dominic Orchard, University of Kent, UK * Ekaterina Komendantskaya, Heriot-Watt University, UK * Garrett Morris, University of Kansas, USA * Heather Miller, EPFL & Northeastern University, CH & USA * Jeremy Yallop, University of Cambridge, UK * Keiko Nakata, SAP Innovation Center Potsdam, DE * Laura Castro, University of A Coru√±a, ESP * Magnus Myreen, Chalmers University of Technology, SWE * Natalia Chechina, Bournemouth University, UK * Peter Achten, Radboud Universiteit Nijmegen, NL * Peter-Michael Osera, Grinnell College, USA * Richard Eisenberg, Bryn Mawr College, USA * Trevor McDonell, University of New South Wales, AUS * Yukiyoshi Kameyama, University of Tsukuba, JAP ### Venue The 30th IFL will take place at the UMass Lowell Inn & Conference Center in Lowell (MA), in association with the University of Massachusetts Lowell. The City of Lowell is located at the heart of the Merrimack Valley just 30 miles northwest of Boston. Lowell can be easily reached by train or taxi. See the website for more information on the venue. ### Acknowledgments This call-for-papers is an adaptation and evolution of content from previous instances of IFL. We are grateful to prior organizers for their work, which is reused here. A part of IFL 2018 format and CFP language that describes conditionally accepted papers has been adapted from call-for-papers of OOPSLA conferences.

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Serialising data between Haskell and C#
by Clinton Mead 12 Mar '18

12 Mar '18

Hi All I want to integrate Haskell into an existing C# project, initially by creating one C# class that basically does all it's "work" in Haskell (and just provides a C# interface). There will be a few types passed in and out of this Haskell module from/to C#. On the C# side, there are classes with members, who's types are probably going to be either Strings, Ints, or lists of Strings/Ints, or lists of other objects. I'd like to have the same types on the Haskell side. It would be nice if I could just magically pass one of these C# types to Haskell and on the Haskell side it will appear as a Haskell type I assume what I'll have to do is serialise the type on the C# side and deserialise on the Haskell side. C# allows one to serialise any data type to XML. Haskell has plenty of serialisation libraries as well. However, the problem I presume is that if I just serialise to XML on the C# side, and deserialise from XML on the Haskell side, if my types are just slightly different, or even if the exact serialisers/deserialises represent their data in different ways, it isn't going to work. It seems like passing complex data to/from Haskell may be a common problem other people experience, so I'm looking for any suggestions on a clean way of doing this.

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Midlands Graduate School 2018 - final call for participation
by Graham Hutton 12 Mar '18

12 Mar '18

Dear all, There are just a few days left now to register for this years Midlands Graduate School (MGS) in Nottingham: eight fantastic courses on dependently typed programming, categories, lambda calculus, semantics, and more. Registration closes on Friday 16th March. Please share! http://tinyurl.com/MGS18NOTT Best wishes, Graham Hutton and Henrik Nilsson ========================================================== Midlands Graduate School 2018 9-13 April 2018, Nottingham, UK http://tinyurl.com/MGS18NOTT BACKGROUND: The Midlands Graduate School (MGS) in the Foundations of Computing Science provides an intensive course of lectures on the mathematical foundations of computing. The MGS has been running since 1999, and is aimed at PhD students in their first or second year of study, but the school is open to everyone, and has increasingly seen participation from industry. We welcome participants from all over the world! COURSES: Eight courses will be given. Participants usually take all the introductory courses and choose additional options from the advanced courses depending on their interests. Invited course - Type-Driven Development with Idris, Edwin Brady Introductory courses - Lambda Calculus, Venanzio Capretta - Category Theory, Roy Crole - Domain Theory and Denotational Semantics, Achim Jung Advanced courses - Univalent Foundations, Benedikt Ahrens - Coalgebra, Alexander Kurz - Separation Logic, Georg Struth - Machine Learning, Michel Valstar REGISTRATION: Registration is £550 for student, academic and independent participants, and £850 for industry participants. The fee includes 5 nights single en-suite accommodation (Sun-Thu), lunch and coffee breaks, and the conference dinner. The registration deadline is ** Friday 16th March **. Spaces are limited, so please register early to secure your place. SPONSORSHIP: We offer a range of sponsorship opportunities for industry (bronze, silver, gold and platinum), each with specific benefits. Please see the website for further details. ========================================================== This message and any attachment are intended solely for the addressee and may contain confidential information. If you have received this message in error, please contact the sender and delete the email and attachment. Any views or opinions expressed by the author of this email do not necessarily reflect the views of the University of Nottingham. Email communications with the University of Nottingham may be monitored where permitted by law.

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Midlands Graduate School 2018 - final call for participation
by Graham Hutton 12 Mar '18

12 Mar '18

Dear all, There are just a few days left now to register for this years Midlands Graduate School (MGS) in Nottingham: eight fantastic courses on dependently typed programming, categories, lambda calculus, semantics, and more. Registration closes on Friday 16th March. Please share! http://tinyurl.com/MGS18NOTT Best wishes, Graham Hutton and Henrik Nilsson ========================================================== Midlands Graduate School 2018 9-13 April 2018, Nottingham, UK http://tinyurl.com/MGS18NOTT BACKGROUND: The Midlands Graduate School (MGS) in the Foundations of Computing Science provides an intensive course of lectures on the mathematical foundations of computing. The MGS has been running since 1999, and is aimed at PhD students in their first or second year of study, but the school is open to everyone, and has increasingly seen participation from industry. We welcome participants from all over the world! COURSES: Eight courses will be given. Participants usually take all the introductory courses and choose additional options from the advanced courses depending on their interests. Invited course - Type-Driven Development with Idris, Edwin Brady Introductory courses - Lambda Calculus, Venanzio Capretta - Category Theory, Roy Crole - Domain Theory and Denotational Semantics, Achim Jung Advanced courses - Univalent Foundations, Benedikt Ahrens - Coalgebra, Alexander Kurz - Separation Logic, Georg Struth - Machine Learning, Michel Valstar REGISTRATION: Registration is £550 for student, academic and independent participants, and £850 for industry participants. The fee includes 5 nights single en-suite accommodation (Sun-Thu), lunch and coffee breaks, and the conference dinner. The registration deadline is ** Friday 16th March **. Spaces are limited, so please register early to secure your place. SPONSORSHIP: We offer a range of sponsorship opportunities for industry (bronze, silver, gold and platinum), each with specific benefits. Please see the website for further details. ========================================================== This message and any attachment are intended solely for the addressee and may contain confidential information. If you have received this message in error, please contact the sender and delete the email and attachment. Any views or opinions expressed by the author of this email do not necessarily reflect the views of the University of Nottingham. Email communications with the University of Nottingham may be monitored where permitted by law.

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A small milestone
by Simon Peyton Jones 11 Mar '18

11 Mar '18

Cherished friends Today is my sixtieth birthday. It is just over forty years since Phil and I called in at Yale on my way to FPCA, and floated the idea of Haskell with Paul Hudak<https://www.microsoft.com/en-us/research/publication/a-history-of-haskell-b…>. (It wasn't called Haskell then, of course.) Rather a lot of water has flowed under the bridge since then. GHC's bug tracker is up to 14,683 tickets; I have read every one of them. But the best thing is Haskell's rich community of smart, motivated, passionate, and friendly colleagues. There was a time when I knew every Haskell programmer on the planet, but we are far, far beyond that point. Now it's beyond me even to keep up with the huge wave of elegant and creative ideas, tools, libraries, and blog posts that you generate. (Kudos to Taylor - and doubtless other colleagues -- for the Haskell Weekly News<https://haskellweekly.news/>, which I love.) But despite its size, it's a community that is still characterised by a love of elegance, and a desire to distil the essence of an idea and encapsulate it in an abstraction, all tempered with respect and tolerance. We don't always live up to these ideals, but by and large we do. Thank you all. Onward and upward! Simon PS: as birthday recreation I'm working on https://ghc.haskell.org/trac/ghc/wiki/QuantifiedContexts

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Re: [Haskell-cafe] [ANNOUNCE] GHC 8.4.1 released
by Ben Gamari 09 Mar '18

09 Mar '18

Vassil Ognyanov Keremidchiev <varosi(a)gmail.com> writes: > I saw there is ARM Aarch64 build, which is pretty cool! But will there be a > ARMv7 (32bit build) as well? > I do hope so. There have been a number of false-starts but hopefully the build that is currently running will finish. Unfortunately getting a working ARMv7 build is rather tricky due to a number of linker bugs that bite under various circumstances. Cheers, - Ben

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Dropping containers support for old GHC versions
by David Feuer 09 Mar '18

09 Mar '18

It's that time again. I'd very much like to drop containers support for GHC version 7.0 (so I can increase the lower bound on array to 0.4 for Safe Haskell-related reasons). I'd also prefer to drop support for GHC versions 7.2 and 7.4, but I'm somewhat open to being convinced not to. What do you all think? David

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Re: [Haskell-cafe] Dropping containers support for old GHC versions
by David Feuer 09 Mar '18

09 Mar '18

On Mar 9, 2018 10:55 AM, "Daniel Cartwright" <chessai1996(a)gmail.com> wrote: On a related note, I find it strange when looking through source code for 'containers'/other Haskell libraries and still see notes about supporting non-GHC Haskell compilers (e.g. Hugs) I believe we've stripped all references to Hugs and nhc98 from containers. If you find any, let us know. I'd be interested in adding support for Frege, but the way it deals with numeric literals could be problematic.

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