Haskell Weekly


Issue 235 2020-10-29

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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.


  • Episode 28: GHC 2021 by Haskell Weekly Podcast

    Does the idea of -XGHC2021 excite you? Cameron Gera and Taylor Fausak work through this proposed set of language extensions.

  • Quicksort in Haskell by Alexander Vershilov

    Making beautiful quicksort real with rewriting rules.

  • Cellular Automaton in Haskell (II). WireWorld by Claes-Magnus Berg

    When making WireWorld we can reuse large parts (with some trivial changes) of the UI made for the implementation of Conway’s Game of Life.

  • Accidentally-Quadratic HashMaps by Jack Kelly

    Unless you’re careful, using foldMap to build HashMaps can take O(n^2) time.

  • Handling of Uncaught Exceptions in Haskell by Ivan Gromakovsky

    When your Haskell application’s thread throws an exception that does not get caught, the Haskell runtime system will handle it and print it based on the Show instance.

  • Haskell: The Bad Parts, part 1 by Michael Snoyman

    Haskell is a great language with some warts. Ideally, we’d get rid of the warts. Second to that: let’s be honest about the warts and warn people away from them.

  • Plucking In, Plucking Out by Matt Parsons

    In The Trouble With Typed Errors, I argue that an error type that is too big is a major problem. But I’ve never really been bothered with an env type that is too big. Why is that?

  • Tagged is not a Newtype by Evan Borden

    As learners get deeper into the ecosystem, as they explore more GHC extensions, they find Tagged and DataKinds.


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

In brief

Show & tell

  • Echoes of Ouroboros

    Echoes of Ouroboros is a 2D puzzle game. Play as a thief who must finish a job … under loopy circumstances!

  • OrboROS

    This is a no-engine game based on raw Vulkan SDK and some Haskell libraries I made to load stuff.

Call for participation