Haskell Weekly


Issue 286 2021-10-21

Subscribe now! We'll never send you spam. You can also follow us on Twitter or with 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.


  • HF Technical Track Elections Results - 2021 by Emily Pillmore

    I’m pleased to announce that the Haskell Foundation Technical Track (HFTT) Elections have concluded, and we have a brand new set of members.

  • Induction without core-size blow-up by Edsko de Vries & Adam Gundry

    The approach described there does however not directly apply to the case of anonymous records. This is the topic we will tackle in this part 2.

  • Into the Future by Andrew Boardman

    In the previous post I talked about what the Haskell Foundation has been up to for the first seven months, now I want to discuss where we’re heading.

  • Proving Equivalence of Polysemy Interpreters by Sandy Maguire

    Last week we looked at how to do property-testing for a polysemy effects’ laws. Today, we’ll investigate how to show that two interpretations are equivalent.

  • Template Haskell — Use Cases by Arnau Abella

    In this blog post, we are going explore a bunch of interesting Template Haskell’s use cases: Type Class Derivation, N-ary Function Generation, Compile-time Static Input Validation, Arbitrary IO at Compile Time.


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

In brief

  • Competitive programming in Haskell: BFS, part 2 (alternative APIs) by Brent Yorgey

    In my last post, I showed how we can solve Modulo Solitaire (and hopefully other BFS problems as well) using a certain API for BFS.

  • Denotational homomorphic testing by Divesh Otwani

    I ended up using something that I’ve been calling denotational homomorphic testing. In this post, I’ll walk through how I ended up with this and why this is legitimately helpful.

  • Epsiode 3: Gabriella Gonzalez by The Haskell Interlude

    We talk about Dhall, Nix, and Haskell, learn why Gabriella’s packages are sometimes called after characters of computer games, and get to know her elevator pitch for educating Haskell.

  • Initial and final encodings of free monads by Li-yao Xia

    Free monads are often introduced as an algebraic data type, an initial encoding. Thanks to that, the term “free monads” tends to be confused with that encoding, even though “free monads” originally refers to a representation-independent idea.

  • Using IO without the IO Monad! by Monday Morning Haskell

    In this article we’re going to demonstrate how we can get limited IO effects within our function. That is, we’ll write our type signature to allow a couple specific IO actions, without opening the door to all kinds of craziness.

Show & tell

  • IHP version 0.15 by Marc Scholten

    A new IHP release with new features and many bug fixes. This release also includes the Stripe Integration and Docker support for IHP Pro and IHP Business users.

Call for participation