Haskell Weekly


Issue 366 2023-05-04

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 activities report: February–March 2023 by Well-Typed

    This is the seventeenth edition of our GHC activities report, which describes the work on GHC and related projects that we are doing at Well-Typed. The current edition covers roughly the months of February and March 2023.

  • Haskell in Production: Standard Chartered by Gints Dreimanis

    In this article of our Haskell in Production series, we interview José Pedro Magalhães from Standard Chartered – a multinational bank that has over 6 million lines of code written in their own dialect of Haskell called Mu.

  • Implementing complex numbers and FFT with just datatypes (no floats) by Victor Taelin

    In this article, I’ll explain why implementing numbers with just algebraic datatypes is desirable. I’ll then talk about common implementations of FFT (Fast Fourier Transform) and why they hide inherent inefficiencies.

  • Refactoring pure function composition without breaking existing tests by Mark Seemann

    This is an article in an series of articles about the epistemology of interaction testing. In short, this collection of articles discusses how to test the composition of pure functions. While a pure function is intrinsically testable, how do you test the composition of pure functions?

  • The “Services” design pattern by Brandon Chinn

    In the Haskell ecosystem, we have quite a few ways to solve this problem: MTL, effect patterns, etc. This blog post will cover an alternative solution, named the “Services” design pattern.

  • Type-safe data processing pipelines by Georg Rudoy

    In this post, we look at one way of representing those dependencies. Namely, dependencies are encoded in the types, allowing compile-time checking and serving as the code documentation.


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

In brief

  • A Block-Based Functional Programming Language

    Im a Univeristy Student currently studying Computer Science at the University of Southampton, and as apart of my Dissertation / Thesis i have created a proof-of-concept tool that combines ideas from the Functional Language Haskell with the Block-Based visual paradigm.

  • Competitive programming in Haskell: tries by Brent Yorgey

    In my previous post, I challenged you to solve Alien Math, which is about reading numbers in some base B, but with a twist.

  • Episode 25: Bodigrim by The Haskell Interlude

    In this episode Joachim Breitner and Wouter Swierstra talk to Andrew Lelechenko also known as Bodigrim. Bodigrim went from a mathematician in theory to a failed PhD developer to the chair of core libraries committee.

  • The Haskell Unfolder Episode 2: quantified constraints by Andres Löh

    In this episode, we will discuss the QuantifiedConstraints language extension.

  • Monthly Hask Anything (May 2023)

    This is your opportunity to ask any questions you feel don’t deserve their own threads, no matter how small or simple they might be!

Call for participation