Haskell Weekly


Issue 65 2017-07-27

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Welcome to another issue of Haskell Weekly! Haskell is a purely functional programming language that focuses on correctness, productivity, and expressiveness. This is a weekly summary of what’s going on in its community.


  • GHC 8.2.1 released

    The GHC developers are very happy to announce the long-awaited 8.2.1 release of Glasgow Haskell Compiler. This is the second release in the 8.0 series. As such, the focus of this release is performance, stability, and consolidation.

  • Announcing Eta v0.1 developer preview

    Today, we’re excited to release the developer preview of Eta which features the first binary release. The focus for this series will be bug fixes, documentation updates, performance improvements, and standard library changes.

  • The RIO monad

    I’ve played with the idea of a RIO (Reader + IO) monad a number of times in the past, but never bit the bullet to do it. As I’ve been hashing out ideas with some people and working through cleanups on Stack, it became clear that the time was right to try this out.

  • Building inline-c projects just got a lot easier

    The latest version of inline-c,, does not require manual specification of generated C files. Moreover, GHCi now works, provided you use -fobject-code. The build process as a whole is much more reliable.

  • Lens tutorial: SimpleLens

    We may not need all of the tools from the lens package. I believe the best way to start using lenses is Haskell is by implementing a simple subset.

  • Homegrown linear monads with RebindableSyntax

    A linear monad class would allow relying on the type system to ensure that a monadic value can only be used once by forcing the bind to consume its first argument (disallowing multiple uses of earlier stream references), effectively making the previously shown runtime errors impossible.

  • Evolution of error messages

    This is the second and final post about Megaparsec 6.0.0 development. This time we are going to walk through re-design of parse error messages.

  • Haskell Summer of Code status update

    In this blog post I talk about my progress in haskell-interactive-mode (clone of haskell-mode). At this point, I’m not an elisp noob anymore. The most important thing that I had to do was, split haskell-interactive-mode from haskell-mode.

  • Halfway there, or “I want to say I know what I’m doing, but it’s a dangerous thing to say”

    Greetings and salutations! If you’re reading this, it means I haven’t died yet, which is pretty great. So, as my last blog post mentioned, I’ve been spending this summer working on a Haskell Summer of Code project: Bringing sanity to the GHC performance test-suite.

  • Haskell library in a C project

    Usually, people are more interested in calling C libraries from Haskell than vice versa. But at NStack, we are going in the opposite direction. We want to build a Haskell library that is going to be used by the programming languages that we support, such as Python.


  • Facebook: Software Engineer, Static Analysis

    Facebook’s Static Analysis team is seeking an experienced software engineer with expertise in C++ and typed functional programming to help build and improve our analysis tools. You will help design and extend Infer for C++, which is used to find bugs across all Facebook engineering.

Are you looking to hire a Haskell developer? Get in touch with info@haskellweekly.news for advertising opportunities!

In brief

Package of the week

This week’s package of the week is una, a universal un-archiving utility application.

Call for participation

Do you have a beginner-friendly issue you want some help with? Email info@haskellweekly.news to get it included here!