Haskell Weekly

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.

Want to see something featured in Haskell Weekly? Open an issue or pull request on GitHub.

Featured

• Using Cloud Haskell to write a type-safe distributed chat

  Cloud Haskell is a set of libraries that combines the power of Haskell’s type system with Erlang’s style of concurrency and distributed programming.

• Strictness surprises in PureScript lazy lists

  It seems that strictness is playing a dirty trick here, evaluating the second cons parameter beforehand against our interest, but strict evaluation is in the nature of PureScript.

• Transforming transformers

  There’s a kind fellow named lunaris on the FPChat slack channel that shares exceptionally good advice. Unfortunately, due to the ephemeral nature of Slack, a lot of this advice is lost to history.

• Dynamic programming in Haskell

  Attempting to program a dynamic programming algorithm in Haskell has helped me understand the fundamental principles behind dynamic programming in a way that I wasn’t able to when I learned it from an imperative programming perspective.

• Your first web application with Spock

  The Spock web framework for Haskell gives you a light but complete foundation to build web servers on, be it for traditional server-side rendered applications, or APIs for single-page applications.

• Coffee, curries, and monads: My journey through Haskell

  What I am going to do is tell you a little about myself, my programming journey, and why I enjoy programming in Haskell. Hopefully it will encourage you to try it out and witness your own joy with the language.

• Property based integration testing using Haskell!

  This article doesn’t require any special functional programming techniques and can be replicated everywhere, but using a functional programming language makes this easier.

• A catamorphic lambda-calculus interpreter

  I was playing around with recursion-schemes, which is pretty cool. It’s very nice to be able to define interpreters like this, so my immediate thought was: can we do this for the lambda-calculus?

• The monad complaint pipeline

  We are a relatively small community, but we’re maybe a little chatty, maybe have a little too much free time waiting for something to compile. Hence we are engaged in near constant internecine war over build tools and the like.

• Lightning fast CI for Haskell projects

  I’ve been working in a few projects at a time in Haskell for the past year, and one point that has been dragging is how much time it takes for a CI job to finish, given this, I started to experiment with other solutions to improve my build feedback loop.

Jobs

• ITProTV seeking Software Developer in Gainesville, Florida

  ITPro.TV is a fast-growing digital media business that focuses on continuing education in technical domains. We are currently accepting applications for full-stack software professionals to join our small but talented multidisciplinary team.

• Anduril Industries is hiring in Orange County

  Come write Haskell, Rust, and Nix (and some C++ when necessary) to make autonomous robots and drones go! If you like FP, interfacing with hardware, and solving problems in detection, tracking, and autonomous vehicle control, send a note to travis@anduril.com

In brief

• Coalescing composite as a monoid
• Function pipeline monoid
• How to compile Haskell to LLVM in 14 simple steps
• IHaskell on CoCalc!
• Next up on MMH!

Package of the week

This week’s package of the week is packcheck, a script for universal build and CI testing of Haskell packages.

Call for participation

• haskanoid: Bump version constraint in dependency on Yampa
• Haskero: Support for case when root project dir is parent of the Stack project
• hledger: Sorting by account codes isn’t working with single-column balance report

Events

• April 27-29: BayHac 2018 in San Francisco, California, United States