Haskell Weekly


Issue 161 2019-05-30

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Welcome to another issue of Haskell Weekly! Haskell is a safe, purely functional programming language with a fast, concurrent runtime. This is a weekly summary of what’s going on in its community.


  • Codata in action, or how to connect Functional Programming and Object Oriented Programming by Javier Casas

    I have been very interested in codata, mainly because it relates to data in a category-theory way, but, as usual, I didn’t understand many of the words involved.

  • Corydalis v0.4 released! by Iustin Pop

    Corydalis is a web-based image/video viewer to be used for local (non-cloud) image collections. Think of it as Geeqie but web-based and understanding your entire image collection.

  • Cursors, Part 5: The Tree Cursor by Tom Sydney Kerckhove

    This is the fifth post in a series about cursors. It prepares the first data structure to write a simple forest editor

  • Dimensions and Haskell: Introduction by Danya Rogozin

    We investigate features of functional programming in the context of machine learning. Python and R are the most widely used languages in this area. In this post, we discuss Haskell advantages in comparison to Python and R.

  • Faking Fundeps with Typechecker Plugins by Sandy Maguire

    Today I want to talk about another sort of GHC plugin: type-checker plugins! TC plugins let you hook into GHC’s constraint machinery and help it solve domain-specific problems that it wouldn’t be able to otherwise.

  • Integrating Lua tests with tasty-lua by Albert Krewinkel

    I wrote a little utility, tasty-lua, to integrate Lua tests into tasty Haskell tests. It’s not much, but I liked how it turned out.

  • Introducing Bipartite Graphs in Alga by Vasily Alferov

    I am a student at Summer of Haskell this year and I am very thankful to authors of this site who provided me this platform to have a blog about GSoC. This is an introduction post about my project.

  • On the arity of type families by Ryan Scott

    Alas, not everything can be partially applied. In particular, GHC offers a type families extension that lets you define functions for use at the type level.

  • Ormolu: Format Haskell code like never before by Mark Karpov

    If we think of the average Haskeller, who do we see? A poor, broken person. Tired head falls into the open palms, sobbing, deprived of the basic human right for automated source code formatting.

  • The Next 700 Module Systems by Musa Al-hassy

    A requirements driven approach to coherent modularisarion constructs in Dependently-typed languages.


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Trying to hire a Haskell developer? You should advertise with us!

In brief

Package of the week

This week’s package of the week is servant-elm, a library that automatically derives Elms functions to query Servant webservices.

Call for participation