Haskell Weekly


Issue 174 2019-08-29

Subscribe now! We'll never send you spam. You can also follow our feed. Read more issues in the archives.

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.


  • GHC 8.8.1 released by Ben Gamari

    The GHC team is very pleased to announce the reelease of GHC 8.8.1. This release is the culmination of over 3000 commits by over one hundred contributors and has several new features and numerous bug fixes relative to GHC 8.6.

  • cabal-install released by Mikhail Glushenkov

    Legacy commands are now only accessible with the v1- prefixes, and the v2- commands are the new default.

  • HSoC — Hadrian Optimisation: Final Report by James Foster

    This project was all about trying to optimise Hadrian, the new build system for GHC which uses Shake instead of Make, with the hope being that faster build times helps GHC devs, which in turn helps everyone in the wider community that uses GHC.

  • Haskell-y Ever After: Summer Tales for Every Full-stack Developer (Part Two) by Andika Demas Riyandi

    A Google Summer of Code’s student story about implementing Haskell on the Hackage Matrix Builder’s frontend application using Functional Reactive Programming approach.

  • Building a Blog in Haskell with Yesod–Giving Back by Riccardo Odone

    This is a series about Yesod: a Haskell web framework that follows a similar philosophy to Rails. In fact, it is strongly opinionated and provides a lot of functionality out of the box.

  • PatternSynonyms for expressive code by Raghu Kaippully

    PatternSynonyms is a very handy GHC extension to abstract away some implementation details of your data types and present a cleaner interface to the rest of the code.

  • Functional Dependencies & Type Families by Gabriel Volpe

    Probably the coolest stuff has been about Functional Dependencies and Type Families, so this is my attempt to explain it in order to gain a better understanding and hopefully help someone else out there as well.

  • Automatic White-Box Testing with Free Monads by Alexander Granin

    Automatic creation of regression tests by designing a system that records the input, output and side-effects of a business application in production.

  • Fixed Points and Non-Fixed Points of Haskell Functors by Ziyang Liu

    I’ve been playing with fixed points of Haskell functors lately and thought it would be useful to write down some of my thoughts, both to solidify my understanding and for future reference.

  • Customizable Datatypes by Michail Pardalos

    This pattern allows parameters to be added in an easy way without cluttering up type signatures and has helped clean up a lot of code.


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 sliceofpy, a library that provides Python-ish slicing traversals for Haskell.

Call for participation