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.

Featured

• “Five-Point Haskell”: Total Depravity (and Defensive Typing) by Justin Le

  In this series, Five-Point Haskell, I’ll set out to establish a five-point framework for typed functional programming (and Haskell-derived) design that aims to produce code that is maintainable, correct, long-lasting, extensible, and beautiful to write and work with. We’ll reference real-world case studies with actual examples when we can, and also attempt to dispel thought-leader sound bites that have become all too popular on Twitter (“heresies”, so to speak).

• Pictures as Functions (Haskell for Dilettantes) by Tea Leaves

  We finish up the first half of the Haskell MOOC from haskell.mooc.fi by exploring a cute little graphics library. We contemplate what it means for functions to be “waiting” for arguments. Can pictures be functions?

Jobs

• Artificial (various engineering positions) by Chris Done

  Artificial is a leading UK-based Insurtech company. Our technology enables some of the world’s largest insurers to write complex risks better and faster. This reduces costs both for end customers and underwriters alike, a win-win. We have built a cool DSL to rapidly and robustly model insurance contracts and a platform around it that enables capturing and processing risks in a highly automated fashion. Our team is fully remote with some people close to our London office in the City working from there on occasion. The choice is yours.

In brief

• algebraic-path: Simple composable type safe file path manipulation library by Nikita Volkov

• Golds-gym: Golden testing for benchmarks by ocramz

  I’m doing quite lot of performance work in this period, and needed an integration between “hspec“ and “benchpress“. The library saves benchmark results to golden files, arranged by architecture, and subsequent tests compare against the golden file to track regressions, improvements etc.

• Introducing Concoct - A declarative UI framework by Matt Hunzinger

  I’ve been playing around with how to do proper declarative UI for awhile now, first in Rust and then Haskell. I finally feel like I found an interesting pattern that works similarly to ReactJS but with type-safety for hooks and other things that get tricky in React.

• vpn-router by Daniil Iaitskov

  vpn-router is a service with the Yesod interface allowing users of a local network to control VPN bypass from their devices via routing adjustments. The service is tested with AmneziaVPN 4.8.10.

Show & tell

• Built a locksmith website with a custom Haskell framework by laurendesouza

  Thought I’d share something our team’s been working on. My co-founder just finished a website for a locksmith business using Jenga, a framework he’s been developing on top of Obelisk.

Call for participation

• agda: Some tests are not invoked by make test
• haskell-language-server: HLS test environment variables should have CLI equivalents